'02 C5 Z06 Diagnostic Codes Help
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Advanced
Joined: Sep 2007
Posts: 58
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'02 C5 Z06 Diagnostic Codes Help
Hi Guys,
I just purchased a an EB '02 Z06 this week. The "sercive active handling" message has came on twice in driving about 120 miles. Then from here I found out how to check the diagnostic codes. Below I listed the codes it gave me and the description I found from here.
TCS
C1221H,C1222H wheel speed sensors sending bad or no signal
C1248H one or more faults have been detected in the EBCM in the ABS/TCS system
C1288H http://forums.corvetteforum.com/show...8&postcount=16
RDCM
B2283H Battery #1 fault
B2285H Battery #2 fault
B2287H +5V reference fault
LDCM
B2282H Battery #1 fault
B2284H Battery #2 fault
U1064H loss of communication with BCM
1)Should I worry about the RDCM and LDCM codes at all?
2)what about C1248 and C1288?
3)Which side wheel speed sensors do C1221 and C1222 refer to?
4)The previous owner changed the rear tires to 315/30, does that have any effect?
Thanks in Advance
I just purchased a an EB '02 Z06 this week. The "sercive active handling" message has came on twice in driving about 120 miles. Then from here I found out how to check the diagnostic codes. Below I listed the codes it gave me and the description I found from here.
TCS
C1221H,C1222H wheel speed sensors sending bad or no signal
C1248H one or more faults have been detected in the EBCM in the ABS/TCS system
C1288H http://forums.corvetteforum.com/show...8&postcount=16
RDCM
B2283H Battery #1 fault
B2285H Battery #2 fault
B2287H +5V reference fault
LDCM
B2282H Battery #1 fault
B2284H Battery #2 fault
U1064H loss of communication with BCM
1)Should I worry about the RDCM and LDCM codes at all?
2)what about C1248 and C1288?
3)Which side wheel speed sensors do C1221 and C1222 refer to?
4)The previous owner changed the rear tires to 315/30, does that have any effect?
Thanks in Advance
Burning Brakes
Joined: Jan 2006
Posts: 1,170
Likes: 27
From: Magnolia Greens NC
Here's some reading for you to start with..
**** all the referenced pictures/photos can be emailed to you once I have your address****
The Basics
Let's cover some basic information on AH, TC, and ABS. In simple terms, these three systems combine data from wheel speed sensors, yaw rate sensors, steering wheel position sensors, along with brake and throttle inputs to determine what the driver wants to do and detects any lose of traction and take corrective action by pulling back on the throttle, activating brakes on individual wheels, or releasing brake pressure as needed to maintain traction.
What goes wrong
When there is a problem anywhere in the system, the computer does not know what's going on with the car or cannot respond correctly. Rather than risking the wrong response which could potentially wreck you car, the whole system is simply disabled for the remainder of the ignition cycle. At this time you will see the ABS and Traction Control warning indicators illuminated on the instrument cluster along with the following messages on the Driver Information Center (DIC):
- Service ABS
- Service Traction System
- Service Active Handling
At this point, you can safely continue to drive your car, just remember that your electronic driving aids are no longer functioning so you should adjust your driving habits accordingly.
Troubleshooting
As I said before, when there is a problem the system is deactivated for the remainder of the ignition cycle, so sometimes everything will go back to normal if you just turn off the car and restart it. If that corrects the problem, it was either a glitch in the system, a lose connection that's going to come back soon or an early sign of a future failure that is coming. Even though the system is now functional it is still beneficial to continue to trouble shoot. The history code should give you a good idea of what to check
The next step is to see where the fault is. If you have several different codes write them down, clear them, and see which ones come back the next time you start the car. At this point, I'm betting that the codes point to either the EBCM or the wheel speed sensors. We'll get to the wheel speed sensors later, for now, let's get to the EBCM.
Electronic Brake Control Module
The most common code for the EBCM is C1214 - Sol Valve relay Contact or coil CKT Open. This code is set when the system voltage is less than 8 volts for 0.23 seconds. Since our goal is to fix this for the lowest price possible, we'll start checking things we can fix for free
The EBCM sits between the engine and radiator. You can see it in the picture on the left below. The EBCM is on the left with the large wire harness coming into it and the sticker on top. The Brake Pressure Modulator Valve (BPMV) in on the right with the brake lines coming out. The EBCM is a dry module, meaning that you can change it out without having to worry about bleeding the ABS system. All of the brake fluid is contained within the BPMV. The coils (seen in the picture on the right below) fit over small spools that have valves inside them. The valves are operated by an electromagnetic field supplied by the coils.
Start by doing a quick visual inspection of the wires. If there are any obvious signs of damage, you've likely found the problem. One member had a problem with the wires rubbing the serpentine belt
Also check to make sure the wire harness has a good connection. If the connection appears solid disconnect it (see step 3 in the replacement instructions below) check the pins to ensure that they have not been bent or damaged in any way. If there is any sign of corrosion, clean it off. Once everything looks good, reseat the harness.
Next, let's move on to the grounds. The EBCM is grounded to the chassis on the left frame rail, just forward of the engine. It's the Black box right in the middle of the picture. As you can see, it's real easy for dirt and moisture to get in that area which isn't exactly good for electronic components. Even if you never drive your car in the rain, it'll still get wet when you wash it, and that could be enough
Start by unbolting the chassis ground, then take the chassis ground connector apart.
These pictures show the corrosion that can build up in the ground connector. If you chassis grounds look like this one, you've probably found the problem. Even if they don't, go ahead and clean it up with a wire brush before putting it back together. Also clean off the chassis and bolt to make sure you've got a good clean ground.
*If you are having any other electrical issues, it's a good idea to check the grounds. These pictures show where the other grounds are.
It's unlikely, but before you break out you credit card and forking over your hard earned money, it's a good idea to check the fuses. One fuse box is located under the hood beside the battery, the second one is under the passenger side of the dash. Remove the floor mat and you will see the access panel. Just pull the fuses out and do a quick visual check.
On the left, you see a good fuse, on the right is a bad fuse
At this point, we know all of the wires are good, but for some reason enough voltage is not getting to the system. It is possible that your battery is not functioning properly. If your battery is a couple of years old, has been drained and recharged a couple of times it might be a good idea to go ahead and replace your battery. This is a long shot for EBCM issues, but I think it's worth a shot before spending several hundred dollars for a new EBCM and you're going to have to replace it eventually anyways. Old batteries can cause a variety of minor electrical issues and you likely have a bunch of history codes for minor issues if the battery is causing the problem.
Now on the EBCM itself. If the electrical contacts inside the relay are dirty or burnt, the vibration from striking the module may change the symptoms or may clear them up for a while. This is by no means a fix or a cure all, in fact it could make it worse or it may not do anything, it's just something to try. Use a small plastic hammer or something similar, lightly tap the front of the EBCM on the lower right corner of the module. The area will be on the right hand side of the lower electrical connection seen in the picture below.
At this point, You've got to additional possibilities. Replace the EBCM or replace both the EBCM and the BPMV. The service manual calls for you to measure the resistance between each pump motor control circuit and the housing of the BPMV, if that checks our okay, you replace the EBCM if not you replace them both. Since most people do not have the equipment to do this the best we can do is to replace the EBCM. If that doesn't work, you'll have to go back and replace the BPMV.
The procedure for replacing the EBCM is very simple. The only special tool you need is a T-20 torx screw driver. I have a Craftsman tool set that has a 1/4" drive screwdriver with and adapter for many different size bit. Unfortunately, the adapter was to long to fit between the EBCM and water pump, so I purchased a set of Craftsman 5 pc. torx screwdriver set that worked fine. A flathead screwdriver may also be needed to pry apart the EBCM from the BPMV
1 - make sure the car is off.
2 - you will probably need to remove the airbridge to get to the EBCM.
3 - remove the wire harness by first removing the white plastic clip that locks it in place (I cut it off and replaced it with a zip-tie) (picture 1), then lift gray handle and pull back on the wire harness (picture 3). At this point, you will be able to see the second wire connection that is removed by pulling down (picture 3).
4 - The service manual call for you the remove the 2 insulator nuts that hold the BPMV to the brackets and lift the EBCM/BPMV out of the bracket. I do not think this step is necessary because there is plenty of room while it is still in the bracket and you do not gain much additional clearance since the brake lines restrict the movement.
5 - Remove the 6 T-20 torx screws connecting the EBCM and BPMV - 1 on each corner and 2 on the sides (picture 2).
6 - "Separate the EBCM from the BPMV by gently pulling apart until separated" - I should start laughing here, but it's not that funny. It's been my experience that anytime the instructions call for you to do something gently, nothing gentle is going to work. In this case, I had to use a flathead screw driver to brake the seal. Once it moved a little, the rest was easy. In addition to the rubber seal, each of the 12 holes you see in picture 3 have a peg in them from the BPMV. Don't go crazy, but be prepared to force them apart.
7 - At this point, all you've got to do is put it all back together. push the new EBCM onto the BPMV.
8 - Replace the 6 T-20 torx screws
9 - reconnect the wire harness
10 - put the intake back on
picture 1 picture 2 picture 3
At this point, the AH/TC/ABS should work normally. If not, you've also got a problem with the BPMV. Although you could replace the BPMV yourself, you have to bleed the ABS system which requires Tech II. For those of you like me that don't have access to Tech II, you've got 2 options. Replace the BPMV yourself and tow the car to a shop with Tech II to have it bled, or just take it in to have the BPMV replaced. The advantage is that you've already done all of the trouble shooting so you want have to pay the mechanic to diagnose the problem for you.
Wheel Speed Sensors
Back to the wheel speed sensors. Code C1221 - 1228 indicate that one of the wheel speed sensors is either sending a bad signal or no signal. Start by checking the connections. The wheel speed sensors are integrated into the wheel bearing/hub assembly pictured below. The wire coming out of the back is the connection for the wheel speed sensors. Verify that the connector are not broken, damaged, or corroded in any way. Pay particular attention to the female end.
The wire coming out of the wheel speed sensor connects to and 18" jumper harness, then to the main harness. It is very common for people to have a weak female pin in one of those connections. If all of that checks out good, Swap the jumper harness from side to side. For example if the left front is bad, swap it over to the right front. and install the good one from the right front to the left side. Then clear the trouble code. If the trouble code is now on the right side, you know the wire harness is the problem. If the code is still on the left side after swapping the jumper harnesses, you know the problem is inside the wheel speed sensors.
If all the wires check out good, it's time to take a trip to Auto Zone for a new set of bearings. You can buy replacement AC Delco bearing from your dealer if you want to, or get the exact same bearing in a different box for half the price (~$150) from Auto Zone, you decide. The bearings should be replaced in axel sets, so if your left front is bad, you have to replace the right front too. While your at it, this is a good time to upgrade the lug studs and add spindle ducts.
Replacement part sources
New EBCMs. Below is a list of part #s and estimated prices from Fred Beans to give you an idea of what you should pay.
Part Number: 10343433
All 2003-2004: $465.58
Part Number: 12216561
All 2002: $610.16
Part Number: 12208997
All 2001: $612.80
Part Number: 9367071
All 1999-2000 w/o Control Active Brakes: $486.40
An alternative to buying a new one is to have your original rebuilt.
For EBCM repair/replace
Call Brandon
877-648-7530 at ABS FIXER
or: www.absfixer.com
$150. plus UPS....warranted as long as You own it
The best place to get replacement wheel bearing/hub assemblies is Auto Zone. You're looking for the Timken brand ones. They are exactly the same as the OEM AC Delco bearings, but sold for about half the price (~$150 vs. $300+ from Chevy).
fuses are available at any auto parts store for, a set of various sizes should cost no more than a few dollars and should last a while.
The Basics
Let's cover some basic information on AH, TC, and ABS. In simple terms, these three systems combine data from wheel speed sensors, yaw rate sensors, steering wheel position sensors, along with brake and throttle inputs to determine what the driver wants to do and detects any lose of traction and take corrective action by pulling back on the throttle, activating brakes on individual wheels, or releasing brake pressure as needed to maintain traction.
What goes wrong
When there is a problem anywhere in the system, the computer does not know what's going on with the car or cannot respond correctly. Rather than risking the wrong response which could potentially wreck you car, the whole system is simply disabled for the remainder of the ignition cycle. At this time you will see the ABS and Traction Control warning indicators illuminated on the instrument cluster along with the following messages on the Driver Information Center (DIC):
- Service ABS
- Service Traction System
- Service Active Handling
At this point, you can safely continue to drive your car, just remember that your electronic driving aids are no longer functioning so you should adjust your driving habits accordingly.
Troubleshooting
As I said before, when there is a problem the system is deactivated for the remainder of the ignition cycle, so sometimes everything will go back to normal if you just turn off the car and restart it. If that corrects the problem, it was either a glitch in the system, a lose connection that's going to come back soon or an early sign of a future failure that is coming. Even though the system is now functional it is still beneficial to continue to trouble shoot. The history code should give you a good idea of what to check
The next step is to see where the fault is. If you have several different codes write them down, clear them, and see which ones come back the next time you start the car. At this point, I'm betting that the codes point to either the EBCM or the wheel speed sensors. We'll get to the wheel speed sensors later, for now, let's get to the EBCM.
Electronic Brake Control Module
The most common code for the EBCM is C1214 - Sol Valve relay Contact or coil CKT Open. This code is set when the system voltage is less than 8 volts for 0.23 seconds. Since our goal is to fix this for the lowest price possible, we'll start checking things we can fix for free
The EBCM sits between the engine and radiator. You can see it in the picture on the left below. The EBCM is on the left with the large wire harness coming into it and the sticker on top. The Brake Pressure Modulator Valve (BPMV) in on the right with the brake lines coming out. The EBCM is a dry module, meaning that you can change it out without having to worry about bleeding the ABS system. All of the brake fluid is contained within the BPMV. The coils (seen in the picture on the right below) fit over small spools that have valves inside them. The valves are operated by an electromagnetic field supplied by the coils.
Start by doing a quick visual inspection of the wires. If there are any obvious signs of damage, you've likely found the problem. One member had a problem with the wires rubbing the serpentine belt
Also check to make sure the wire harness has a good connection. If the connection appears solid disconnect it (see step 3 in the replacement instructions below) check the pins to ensure that they have not been bent or damaged in any way. If there is any sign of corrosion, clean it off. Once everything looks good, reseat the harness.
Next, let's move on to the grounds. The EBCM is grounded to the chassis on the left frame rail, just forward of the engine. It's the Black box right in the middle of the picture. As you can see, it's real easy for dirt and moisture to get in that area which isn't exactly good for electronic components. Even if you never drive your car in the rain, it'll still get wet when you wash it, and that could be enough
Start by unbolting the chassis ground, then take the chassis ground connector apart.
These pictures show the corrosion that can build up in the ground connector. If you chassis grounds look like this one, you've probably found the problem. Even if they don't, go ahead and clean it up with a wire brush before putting it back together. Also clean off the chassis and bolt to make sure you've got a good clean ground.
*If you are having any other electrical issues, it's a good idea to check the grounds. These pictures show where the other grounds are.
It's unlikely, but before you break out you credit card and forking over your hard earned money, it's a good idea to check the fuses. One fuse box is located under the hood beside the battery, the second one is under the passenger side of the dash. Remove the floor mat and you will see the access panel. Just pull the fuses out and do a quick visual check.
On the left, you see a good fuse, on the right is a bad fuse
At this point, we know all of the wires are good, but for some reason enough voltage is not getting to the system. It is possible that your battery is not functioning properly. If your battery is a couple of years old, has been drained and recharged a couple of times it might be a good idea to go ahead and replace your battery. This is a long shot for EBCM issues, but I think it's worth a shot before spending several hundred dollars for a new EBCM and you're going to have to replace it eventually anyways. Old batteries can cause a variety of minor electrical issues and you likely have a bunch of history codes for minor issues if the battery is causing the problem.
Now on the EBCM itself. If the electrical contacts inside the relay are dirty or burnt, the vibration from striking the module may change the symptoms or may clear them up for a while. This is by no means a fix or a cure all, in fact it could make it worse or it may not do anything, it's just something to try. Use a small plastic hammer or something similar, lightly tap the front of the EBCM on the lower right corner of the module. The area will be on the right hand side of the lower electrical connection seen in the picture below.
At this point, You've got to additional possibilities. Replace the EBCM or replace both the EBCM and the BPMV. The service manual calls for you to measure the resistance between each pump motor control circuit and the housing of the BPMV, if that checks our okay, you replace the EBCM if not you replace them both. Since most people do not have the equipment to do this the best we can do is to replace the EBCM. If that doesn't work, you'll have to go back and replace the BPMV.
The procedure for replacing the EBCM is very simple. The only special tool you need is a T-20 torx screw driver. I have a Craftsman tool set that has a 1/4" drive screwdriver with and adapter for many different size bit. Unfortunately, the adapter was to long to fit between the EBCM and water pump, so I purchased a set of Craftsman 5 pc. torx screwdriver set that worked fine. A flathead screwdriver may also be needed to pry apart the EBCM from the BPMV
1 - make sure the car is off.
2 - you will probably need to remove the airbridge to get to the EBCM.
3 - remove the wire harness by first removing the white plastic clip that locks it in place (I cut it off and replaced it with a zip-tie) (picture 1), then lift gray handle and pull back on the wire harness (picture 3). At this point, you will be able to see the second wire connection that is removed by pulling down (picture 3).
4 - The service manual call for you the remove the 2 insulator nuts that hold the BPMV to the brackets and lift the EBCM/BPMV out of the bracket. I do not think this step is necessary because there is plenty of room while it is still in the bracket and you do not gain much additional clearance since the brake lines restrict the movement.
5 - Remove the 6 T-20 torx screws connecting the EBCM and BPMV - 1 on each corner and 2 on the sides (picture 2).
6 - "Separate the EBCM from the BPMV by gently pulling apart until separated" - I should start laughing here, but it's not that funny. It's been my experience that anytime the instructions call for you to do something gently, nothing gentle is going to work. In this case, I had to use a flathead screw driver to brake the seal. Once it moved a little, the rest was easy. In addition to the rubber seal, each of the 12 holes you see in picture 3 have a peg in them from the BPMV. Don't go crazy, but be prepared to force them apart.
7 - At this point, all you've got to do is put it all back together. push the new EBCM onto the BPMV.
8 - Replace the 6 T-20 torx screws
9 - reconnect the wire harness
10 - put the intake back on
picture 1 picture 2 picture 3
At this point, the AH/TC/ABS should work normally. If not, you've also got a problem with the BPMV. Although you could replace the BPMV yourself, you have to bleed the ABS system which requires Tech II. For those of you like me that don't have access to Tech II, you've got 2 options. Replace the BPMV yourself and tow the car to a shop with Tech II to have it bled, or just take it in to have the BPMV replaced. The advantage is that you've already done all of the trouble shooting so you want have to pay the mechanic to diagnose the problem for you.
Wheel Speed Sensors
Back to the wheel speed sensors. Code C1221 - 1228 indicate that one of the wheel speed sensors is either sending a bad signal or no signal. Start by checking the connections. The wheel speed sensors are integrated into the wheel bearing/hub assembly pictured below. The wire coming out of the back is the connection for the wheel speed sensors. Verify that the connector are not broken, damaged, or corroded in any way. Pay particular attention to the female end.
The wire coming out of the wheel speed sensor connects to and 18" jumper harness, then to the main harness. It is very common for people to have a weak female pin in one of those connections. If all of that checks out good, Swap the jumper harness from side to side. For example if the left front is bad, swap it over to the right front. and install the good one from the right front to the left side. Then clear the trouble code. If the trouble code is now on the right side, you know the wire harness is the problem. If the code is still on the left side after swapping the jumper harnesses, you know the problem is inside the wheel speed sensors.
If all the wires check out good, it's time to take a trip to Auto Zone for a new set of bearings. You can buy replacement AC Delco bearing from your dealer if you want to, or get the exact same bearing in a different box for half the price (~$150) from Auto Zone, you decide. The bearings should be replaced in axel sets, so if your left front is bad, you have to replace the right front too. While your at it, this is a good time to upgrade the lug studs and add spindle ducts.
Replacement part sources
New EBCMs. Below is a list of part #s and estimated prices from Fred Beans to give you an idea of what you should pay.
Part Number: 10343433
All 2003-2004: $465.58
Part Number: 12216561
All 2002: $610.16
Part Number: 12208997
All 2001: $612.80
Part Number: 9367071
All 1999-2000 w/o Control Active Brakes: $486.40
An alternative to buying a new one is to have your original rebuilt.
For EBCM repair/replace
Call Brandon
877-648-7530 at ABS FIXER
or: www.absfixer.com
$150. plus UPS....warranted as long as You own it
The best place to get replacement wheel bearing/hub assemblies is Auto Zone. You're looking for the Timken brand ones. They are exactly the same as the OEM AC Delco bearings, but sold for about half the price (~$150 vs. $300+ from Chevy).
fuses are available at any auto parts store for, a set of various sizes should cost no more than a few dollars and should last a while.
Thread Starter
Advanced
Joined: Sep 2007
Posts: 58
Likes: 0
thanks for the detailed response.
my e-mail is "icedemn 'at' hotmail.com"
Is the "1-4 shift" light supposed to come on at about 1500-2000 rpm in 1st gear? I've tried to shift from 1st to 2nd gear a couple of times in that range and that light comes on and doesn't allow me to go into 2nd gear.
I'm at 46,500 miles and the car has extended warranty until 48,000 miles. If these codes have H behind them, which they do, will the warranty still cover and replace everything for no charge?
Happy New Year
my e-mail is "icedemn 'at' hotmail.com"
Is the "1-4 shift" light supposed to come on at about 1500-2000 rpm in 1st gear? I've tried to shift from 1st to 2nd gear a couple of times in that range and that light comes on and doesn't allow me to go into 2nd gear.
I'm at 46,500 miles and the car has extended warranty until 48,000 miles. If these codes have H behind them, which they do, will the warranty still cover and replace everything for no charge?
Happy New Year
Safety Car
Joined: Jan 2001
Posts: 4,386
Likes: 689
From: Boise ID
thanks for the detailed response.
my e-mail is "icedemn 'at' hotmail.com"
Is the "1-4 shift" light supposed to come on at about 1500-2000 rpm in 1st gear? I've tried to shift from 1st to 2nd gear a couple of times in that range and that light comes on and doesn't allow me to go into 2nd gear.
I'm at 46,500 miles and the car has extended warranty until 48,000 miles. If these codes have H behind them, which they do, will the warranty still cover and replace everything for no charge?
Happy New Year
my e-mail is "icedemn 'at' hotmail.com"
Is the "1-4 shift" light supposed to come on at about 1500-2000 rpm in 1st gear? I've tried to shift from 1st to 2nd gear a couple of times in that range and that light comes on and doesn't allow me to go into 2nd gear.
I'm at 46,500 miles and the car has extended warranty until 48,000 miles. If these codes have H behind them, which they do, will the warranty still cover and replace everything for no charge?
Happy New Year
The engine coolant temperature is higher than 169F (76C),
you are going 15 to 19 mph (24 to 31 km/h) and
you are at 21 percent throttle or less.
As far as the codes, you might try clearing the history and see what comes back after some driving.
Burning Brakes
Joined: Jan 2006
Posts: 1,170
Likes: 27
From: Magnolia Greens NC
thanks for the detailed response.
my e-mail is "icedemn 'at' hotmail.com" GOT IT! EMAILING NOW
Is the "1-4 shift" light supposed to come on at about 1500-2000 rpm in 1st gear? I've tried to shift from 1st to 2nd gear a couple of times in that range and that light comes on and doesn't allow me to go into 2nd gear. INCREASE THE REVS, BETWEEN THAT SHIFT, & IT WON'T ENGAGE THE 1st to 4th shift FUNCTION
I'm at 46,500 miles and the car has extended warranty until 48,000 miles. If these codes have H behind them, which they do, will the warranty still cover and replace everything for no charge?
IF YOU STILL HAVE 100% WARRANTY, THEY SHOULD FIX YOUR PROBLEM, BUT INQUIRE 1st if you will have to pay any % share...And, even if you have deleted those history (H) codes, diagnostic testing will reveal these and a qualified shop will know the solution for each.
Happy New Year
my e-mail is "icedemn 'at' hotmail.com" GOT IT! EMAILING NOW
Is the "1-4 shift" light supposed to come on at about 1500-2000 rpm in 1st gear? I've tried to shift from 1st to 2nd gear a couple of times in that range and that light comes on and doesn't allow me to go into 2nd gear. INCREASE THE REVS, BETWEEN THAT SHIFT, & IT WON'T ENGAGE THE 1st to 4th shift FUNCTION
I'm at 46,500 miles and the car has extended warranty until 48,000 miles. If these codes have H behind them, which they do, will the warranty still cover and replace everything for no charge?
IF YOU STILL HAVE 100% WARRANTY, THEY SHOULD FIX YOUR PROBLEM, BUT INQUIRE 1st if you will have to pay any % share...And, even if you have deleted those history (H) codes, diagnostic testing will reveal these and a qualified shop will know the solution for each.
Happy New Year
Thread Starter
Advanced
Joined: Sep 2007
Posts: 58
Likes: 0
thanks guys, I will clear the codes and see if any of them come back.
also:
Which side wheel speed sensors do C1221 and C1222 codes refer to?
The previous owner changed the rear tires to 315/30/18, does that have any effect?
also:
Which side wheel speed sensors do C1221 and C1222 codes refer to?
The previous owner changed the rear tires to 315/30/18, does that have any effect?
Last edited by ultimatetsi; Jan 2, 2008 at 04:10 PM.
Safety Car
Joined: Jan 2001
Posts: 4,386
Likes: 689
From: Boise ID
DTC C1221 LF Wheel Speed Sensor Input Signal is 0
DTC C1222 RF Wheel Speed Sensor Input Signal is 0
Circuit Description
The speed sensor used on this vehicle is a single point magnetic pickup. This sensor produces an AC signal that the EBCM uses the frequency from to calculate the wheel speed.
Conditions for Setting the DTC
The DTC will set if one wheel speed = 0 and the other WSS are greater than 8 km/h (5 mph) for 2.5 seconds.
Action Taken When the DTC Sets
ABS/TCS/Active Handling (if equipped with RPO JL4) are disabled.
Indicators that turn on:
ABS indicator
Car Icon (TCS indicator)
Messages displayed on the DIC:
Service ABS
Service Traction System
Service Active HNDLG (if equipped with Active Handling RPO JL4)
Conditions for Clearing the DTC
Condition for DTC is no longer present and scan tool clear DTC function is used.
Fifty ignition cycles have passed with no DTCs detected.
Diagnostic Aids
It is very important that a thorough inspection of the wiring and connectors be performed. Failure to carefully and fully inspect wiring and connectors may result in misdiagnosis, causing part replacement with reappearance of the malfunction.
An intermittent malfunction can be caused by poor connections, broken insulation, or a wire that is broken inside the insulation.
If an intermittent malfunction exists refer to Intermittents and Poor Connections in Wiring Systems.
DTC C1222 RF Wheel Speed Sensor Input Signal is 0
Circuit Description
The speed sensor used on this vehicle is a single point magnetic pickup. This sensor produces an AC signal that the EBCM uses the frequency from to calculate the wheel speed.
Conditions for Setting the DTC
The DTC will set if one wheel speed = 0 and the other WSS are greater than 8 km/h (5 mph) for 2.5 seconds.
Action Taken When the DTC Sets
ABS/TCS/Active Handling (if equipped with RPO JL4) are disabled.
Indicators that turn on:
ABS indicator
Car Icon (TCS indicator)
Messages displayed on the DIC:
Service ABS
Service Traction System
Service Active HNDLG (if equipped with Active Handling RPO JL4)
Conditions for Clearing the DTC
Condition for DTC is no longer present and scan tool clear DTC function is used.
Fifty ignition cycles have passed with no DTCs detected.
Diagnostic Aids
It is very important that a thorough inspection of the wiring and connectors be performed. Failure to carefully and fully inspect wiring and connectors may result in misdiagnosis, causing part replacement with reappearance of the malfunction.
An intermittent malfunction can be caused by poor connections, broken insulation, or a wire that is broken inside the insulation.
If an intermittent malfunction exists refer to Intermittents and Poor Connections in Wiring Systems.
Burning Brakes
Joined: Jan 2006
Posts: 1,170
Likes: 27
From: Magnolia Greens NC
[QUOTE=ultimatetsi;1563435200]thanks guys, I will clear the codes and see if any of them come back.
also:
Which side wheel speed sensors do C1221 and C1222 codes refer to?
DTC C1221 LF Wheel Speed Sensor Input Signal is 0
DTC C1222 RF Wheel Speed Sensor Input Signal is 0
The previous owner changed the rear tires to 315/30/18, does that have any effect? IT SHOULD'NT
also:
Which side wheel speed sensors do C1221 and C1222 codes refer to?
DTC C1221 LF Wheel Speed Sensor Input Signal is 0
DTC C1222 RF Wheel Speed Sensor Input Signal is 0
The previous owner changed the rear tires to 315/30/18, does that have any effect? IT SHOULD'NT
Last edited by trussme; Jan 2, 2008 at 04:38 PM.
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Tech Contributor
Joined: Oct 1999
Posts: 41,044
Likes: 9,808
From: Charlotte, NC (formerly Endicott, NY)
With a Z it is likely you have GMPP as your Service Plan since a lot of other plans won't insure the Z for some reason. If it is GMPP the deductible can be $0, or something like $50, $100 or maybe $200. The deductible is based on a per visit to the shop basis versus the number of repairs made so a large number of repairs can be covered in one visit. However, they will not cover the battery and based on the combination of codes you have there is a strong possibility you may have a battery problem or a poor voltage or ground connection at the battery. Check the battery and its connections first.
C1248 indicates you have 2 wheel speed sensors on the same axle reporting problems and that Dynamic Rear Proportioning has been disabled. A low voltage can cause the EBCM to misread the wheel speed sensor signals.
C1288 indicates there is an issue with the steering wheel position sensor. Low voltage can cause problems here also.
The door control modules indicate there are definite voltage problems with those modules so the battery and its connections become suspect.
ABS related Diagnostics
DTC C1248
Circuit Description
The dynamic rear proportioning (DRP) is a control system that replaces the hydraulic proportioning function of the mechanical proportioning valve in the base brake system. The DRP control system is part of the operating software in the EBCM. The DRP uses active control with the existing ABS in order to regulate the vehicle's rear brake pressure.
Conditions for Running the DTC
One or more faults have been detected by the EBCM in the ABS/TCS systems.
Conditions for Setting the DTC
One of the following conditions exits:
DTC C1236 sets and ignition voltage is less than 8.5 volts.
DTC C1254 or C1255 sets.
DTCs C1265 and C1267 set.
Two wheel speed sensor DTCs on the same axle set.
Action Taken When the DTC Sets
The EBCM disables the DRP for the duration of the ignition cycle.
The red Brake warning indicator turns ON.
Conditions for Clearing the DTC
The condition for the DTC is no longer present and the DTC is cleared with a scan tool.
The EBCM automatically clears the history DTC when a current DTC is not detected in 100 consecutive drive cycles.
Diagnostic Aids
Use this DTC in order to differentiate which of the following conditions is present:
The EBCM turned ON the red Brake warning indicator.
The instrument cluster turned ON the red Brake warning indicator due to low brake fluid in the master cylinder reservoir.
The instrument cluster turned ON the red Brake warning indicator due to the application of the park brake.
Diagnose any other ABS DTCs that set along with this DTC.
DTC C1287 or C1288
Circuit Description
The vehicle stability enhancement system (VSES) is activated by the electronic brake control mdoule (EBCM) calculating the desired yaw rate and comparing it to the actual yaw rate input. The desired yaw rate is calculated from measured steering wheel position, vehicle speed, and lateral acceleration. The difference between the desired yaw rate and actual yaw rate is the yaw rate error, which is a measurement of oversteer or understeer. If the yaw rate error becomes too large, the EBCM will attempt to correct the vehicle's yaw motion by applying differential braking to the left or right front wheel.
The amount of differential braking applied to the left or right front wheel is based on both the yaw rate error and side slip rate error. The side slip rate error is a function of the lateral acceleration minus the product of the yaw rate and vehicle speed. The yaw rate error and side slip rate error are combined to produce the total delta velocity error. When the delta velocity error becomes too large and the VSES system activates, the drivers steering inputs combined with the differential braking will attempt to bring the delta velocity error toward zero.
The VSES activations generally occur during aggressive driving, in the turns or bumpy roads without much use of the accelerator pedal. When braking during VSES activation, the brake pedal will feel different than the ABS pedal pulsation. The brake pedal pulsates at a higher frequency during VSES activation.
Conditions for Running the DTC
The ignition is ON.
Conditions for Setting the DTC
C1287
One of the following conditions exists:
The steering wheel position sensor is synchronized and the steer rate (speed that the steering wheel appears to be turning) is greater than 1100 degrees/second.
The steer rate is less than 80 degrees/second and the difference in the phase angle between Phase A and Phase B is greater than 20 degrees.
The 2 steering sensor signals (Phase A and Phase B) do not agree for 1 second. Under this condition, this DTC will set along with DTC C1281.
C1288
One of the following conditions exists:
Both Phase A and Phase B are greater than 4.9 volts for 1.6 seconds.
Both Phase A and Phase B are less than 0.2 volts for 1.6 seconds.
The difference in the changes in Phase A and Phase B is greater than 35.2 degrees for 9.76 milliseconds.
Action Taken When the DTC Sets
The EBCM disables the VSES for the duration of the ignition cycle.
The Traction Control and Active Handling indicator turns ON.
The DIC displays the Service Active Handling message.
The ABS remains functional.
Conditions for Clearing the DTC
The condition for the DTC is no longer present and the DTC is cleared with a scan tool.
The EBCM automatically clears the history DTC when a current DTC is not detected in 100 consecutive drive cycles.
Diagnostic Aids
The scan tool may display 2 additional characters after the DTC. Take note of the 2 character code and any other DTCs that are set. The 2 character code is an engineering aid used in order to determine the specific criteria which caused the DTC to set.
During diagnosis, park the vehicle on a level surface.
Check the vehicle for proper alignment. The car should not pull in either direction while driving straight on a level surface.
Find out from the driver under what conditions the DTC was set (when the DIC displayed the Service Active Handling message). This information will help to duplicate the failure.
Door Control Module Related Diagnostics
DTC B2282-B2285
Circuit Description
The driver door module (DDM) and passenger door module (PDM) each have a high and low power feed . The low power feed, battery 1, is used to provide power for the door module logic and internal driver operation. The high power feed, battery 2, is used to provide power for systems that draw higher amounts of current. The door modules monitor the voltage level at battery 1 and battery 2 to determine if the voltage level is out of range. If the voltage level is out of range, a DTC is set.
Conditions for Setting the DTC
The door module detects battery 1 or battery 2 voltage range under 8.5 volts or over 16.3 volts.
Condition must be present for greater than 2 seconds.
Action Taken When the DTC Sets
Stores a history DTC B2282, B2283, B2284 or B2285 in the door module memory.
These DTCs can only be set as a history code even if the malfunction is current.
No driver warning message will be displayed for this DTC.
Conditions for Clearing the DTC
The door module no longer detects battery 1 or battery 2 voltage below 8.5 volts or higher than 16.3 volts for greater than 2 seconds.
The DTC is cleared using the IPC clearing feature, or
The DTC is cleared using a scan tool.
Diagnostic Aids
The following conditions may cause an intermittent malfunction:
There is an intermittent open or short to ground in a battery 1 or battery 2 circuit.
The battery voltage is out of range.
A charging system malfunction.
Using a scan tool, select DCM Data display and monitor battery 1 and battery 2 voltage while operating the door locks and heated mirrors. This can determine if battery 1 or battery 2 voltage is affected by these devises and can help duplicate the malfunction.
If the DTC does not reset after the code is cleared, then the problem may be intermittent. Refer to Testing for Intermittent and Poor Connections in Wiring Systems.
Check the PWRFDL fuse.
Bill
C1248 indicates you have 2 wheel speed sensors on the same axle reporting problems and that Dynamic Rear Proportioning has been disabled. A low voltage can cause the EBCM to misread the wheel speed sensor signals.
C1288 indicates there is an issue with the steering wheel position sensor. Low voltage can cause problems here also.
The door control modules indicate there are definite voltage problems with those modules so the battery and its connections become suspect.
ABS related Diagnostics
DTC C1248
Circuit Description
The dynamic rear proportioning (DRP) is a control system that replaces the hydraulic proportioning function of the mechanical proportioning valve in the base brake system. The DRP control system is part of the operating software in the EBCM. The DRP uses active control with the existing ABS in order to regulate the vehicle's rear brake pressure.
Conditions for Running the DTC
One or more faults have been detected by the EBCM in the ABS/TCS systems.
Conditions for Setting the DTC
One of the following conditions exits:
DTC C1236 sets and ignition voltage is less than 8.5 volts.
DTC C1254 or C1255 sets.
DTCs C1265 and C1267 set.
Two wheel speed sensor DTCs on the same axle set.
Action Taken When the DTC Sets
The EBCM disables the DRP for the duration of the ignition cycle.
The red Brake warning indicator turns ON.
Conditions for Clearing the DTC
The condition for the DTC is no longer present and the DTC is cleared with a scan tool.
The EBCM automatically clears the history DTC when a current DTC is not detected in 100 consecutive drive cycles.
Diagnostic Aids
Use this DTC in order to differentiate which of the following conditions is present:
The EBCM turned ON the red Brake warning indicator.
The instrument cluster turned ON the red Brake warning indicator due to low brake fluid in the master cylinder reservoir.
The instrument cluster turned ON the red Brake warning indicator due to the application of the park brake.
Diagnose any other ABS DTCs that set along with this DTC.
DTC C1287 or C1288
Circuit Description
The vehicle stability enhancement system (VSES) is activated by the electronic brake control mdoule (EBCM) calculating the desired yaw rate and comparing it to the actual yaw rate input. The desired yaw rate is calculated from measured steering wheel position, vehicle speed, and lateral acceleration. The difference between the desired yaw rate and actual yaw rate is the yaw rate error, which is a measurement of oversteer or understeer. If the yaw rate error becomes too large, the EBCM will attempt to correct the vehicle's yaw motion by applying differential braking to the left or right front wheel.
The amount of differential braking applied to the left or right front wheel is based on both the yaw rate error and side slip rate error. The side slip rate error is a function of the lateral acceleration minus the product of the yaw rate and vehicle speed. The yaw rate error and side slip rate error are combined to produce the total delta velocity error. When the delta velocity error becomes too large and the VSES system activates, the drivers steering inputs combined with the differential braking will attempt to bring the delta velocity error toward zero.
The VSES activations generally occur during aggressive driving, in the turns or bumpy roads without much use of the accelerator pedal. When braking during VSES activation, the brake pedal will feel different than the ABS pedal pulsation. The brake pedal pulsates at a higher frequency during VSES activation.
Conditions for Running the DTC
The ignition is ON.
Conditions for Setting the DTC
C1287
One of the following conditions exists:
The steering wheel position sensor is synchronized and the steer rate (speed that the steering wheel appears to be turning) is greater than 1100 degrees/second.
The steer rate is less than 80 degrees/second and the difference in the phase angle between Phase A and Phase B is greater than 20 degrees.
The 2 steering sensor signals (Phase A and Phase B) do not agree for 1 second. Under this condition, this DTC will set along with DTC C1281.
C1288
One of the following conditions exists:
Both Phase A and Phase B are greater than 4.9 volts for 1.6 seconds.
Both Phase A and Phase B are less than 0.2 volts for 1.6 seconds.
The difference in the changes in Phase A and Phase B is greater than 35.2 degrees for 9.76 milliseconds.
Action Taken When the DTC Sets
The EBCM disables the VSES for the duration of the ignition cycle.
The Traction Control and Active Handling indicator turns ON.
The DIC displays the Service Active Handling message.
The ABS remains functional.
Conditions for Clearing the DTC
The condition for the DTC is no longer present and the DTC is cleared with a scan tool.
The EBCM automatically clears the history DTC when a current DTC is not detected in 100 consecutive drive cycles.
Diagnostic Aids
The scan tool may display 2 additional characters after the DTC. Take note of the 2 character code and any other DTCs that are set. The 2 character code is an engineering aid used in order to determine the specific criteria which caused the DTC to set.
During diagnosis, park the vehicle on a level surface.
Check the vehicle for proper alignment. The car should not pull in either direction while driving straight on a level surface.
Find out from the driver under what conditions the DTC was set (when the DIC displayed the Service Active Handling message). This information will help to duplicate the failure.
Door Control Module Related Diagnostics
DTC B2282-B2285
Circuit Description
The driver door module (DDM) and passenger door module (PDM) each have a high and low power feed . The low power feed, battery 1, is used to provide power for the door module logic and internal driver operation. The high power feed, battery 2, is used to provide power for systems that draw higher amounts of current. The door modules monitor the voltage level at battery 1 and battery 2 to determine if the voltage level is out of range. If the voltage level is out of range, a DTC is set.
Conditions for Setting the DTC
The door module detects battery 1 or battery 2 voltage range under 8.5 volts or over 16.3 volts.
Condition must be present for greater than 2 seconds.
Action Taken When the DTC Sets
Stores a history DTC B2282, B2283, B2284 or B2285 in the door module memory.
These DTCs can only be set as a history code even if the malfunction is current.
No driver warning message will be displayed for this DTC.
Conditions for Clearing the DTC
The door module no longer detects battery 1 or battery 2 voltage below 8.5 volts or higher than 16.3 volts for greater than 2 seconds.
The DTC is cleared using the IPC clearing feature, or
The DTC is cleared using a scan tool.
Diagnostic Aids
The following conditions may cause an intermittent malfunction:
There is an intermittent open or short to ground in a battery 1 or battery 2 circuit.
The battery voltage is out of range.
A charging system malfunction.
Using a scan tool, select DCM Data display and monitor battery 1 and battery 2 voltage while operating the door locks and heated mirrors. This can determine if battery 1 or battery 2 voltage is affected by these devises and can help duplicate the malfunction.
If the DTC does not reset after the code is cleared, then the problem may be intermittent. Refer to Testing for Intermittent and Poor Connections in Wiring Systems.
Check the PWRFDL fuse.
Bill
Le Mans Master
Joined: Mar 2002
Posts: 5,955
Likes: 161
From: PNW
Install a "Skip Shift Eliminator" unit. It plugs in on a wire harness on the transmission and disables the skip shift mechanism. The light on the dash will still come on as usual, but you will be able to shift from 1st to 2nd gear while the light it on.
Another way around it is to shift after 2500 RPMs. I did this for a couple of years, and would get caught a few times trying to shift into 2nd gear between 2000 and 2500. Just a few times even gets frustrating, so went with the eliminator. Here's one (of many on the market) for about $22 -- http://www.southerncarparts.com/corv...tor-p-104.html
Tons of threads about it.
http://forums.corvetteforum.com/show...ift+eliminator
Last edited by ZeeOSix; Jan 3, 2008 at 07:39 PM.
Safety Car
Joined: Aug 2000
Posts: 4,933
Likes: 30
From: San Rafael CA
http://www.ecklers.com/product.asp?p...3&dept_id=1748
$23.99 .... takes longer to get the car up on ramps than to install .... less than 5 minutes for the install .....
$23.99 .... takes longer to get the car up on ramps than to install .... less than 5 minutes for the install .....
Safety Car
Joined: Aug 2000
Posts: 4,933
Likes: 30
From: San Rafael CA
Since it does not affect vehicle emissions, it is legal to "bypass" the CAGS feature. I'll gladly spend a few bucks to disable CAGS in return for that upfront tax savings.
