Persistent DIC Warning Messages- Have History Codes But No Current Codes Present
08-02-2012, 10:11 AM
#1
Le Mans Master
Thread Starter
Persistent DIC Warning Messages- Have History Codes But No Current Codes Present
I'm getting these messages in the DIC and they keep coming back within a few minutes of pushing "Reset":
Service Active Handling
Service ABS
Service Traction Control
The only codes I currently have are C1233H and C1283H
I have had some battery and battery charging issues in the past (Battery Tender malfunctioned and boiled one of the batteries down low on water, one cell nearly all the way), but new battery installed now and new BT.
About the time I was having battery trouble I also got a check charging system message in the DIC but no other messages and the check charging system message only appeared once. I did not look for codes at that time as everything seemed to be operating properly.
Shortly after that the DIC began displaying Service Active Handling, Service ABS, and Service Traction Control. A check of codes then showed I had all of these:
C1282HC Yaw Rate Sensor Bias Circuit Malfunction
C1284HC Lateral Accelerometer Sensor- Self Test Fault
C1285HC Lateral Accelerometer Sensor Circuit Malfunction
C1287HC Steering Sensor Rate Malfunction
C1288HC Steering Wheel Position Sensor
C1296HC Master Cylinder Brake Pressure Sensor Circuit Open Or Shorted
Additionally there were two other TCS codes stored:
C1233H RF Wheel Speed Circuit Open or Shorted
C1237H High System Supply Voltage
I no longer have any of the codes above except for C1233H and the new one, C1283H. Because these are history codes does this mean the fault is no longer present and if so why can't I extinguish the three DIC warnings for ABS, Active Handling and Traction Control?
The Helms Manual says an EBCM relay may have switched off these circuits when it sensed over voltage and will have to be reset with a Tech-2 or I can wait 100 ignition cycles and the EBCM will do that if it does not detect a recurrence. Am I on the right track before I start checking and cleaning all the grounds? 04 with 2K miles.
Service Active Handling
Service ABS
Service Traction Control
The only codes I currently have are C1233H and C1283H
I have had some battery and battery charging issues in the past (Battery Tender malfunctioned and boiled one of the batteries down low on water, one cell nearly all the way), but new battery installed now and new BT.
About the time I was having battery trouble I also got a check charging system message in the DIC but no other messages and the check charging system message only appeared once. I did not look for codes at that time as everything seemed to be operating properly.
Shortly after that the DIC began displaying Service Active Handling, Service ABS, and Service Traction Control. A check of codes then showed I had all of these:
C1282HC Yaw Rate Sensor Bias Circuit Malfunction
C1284HC Lateral Accelerometer Sensor- Self Test Fault
C1285HC Lateral Accelerometer Sensor Circuit Malfunction
C1287HC Steering Sensor Rate Malfunction
C1288HC Steering Wheel Position Sensor
C1296HC Master Cylinder Brake Pressure Sensor Circuit Open Or Shorted
Additionally there were two other TCS codes stored:
C1233H RF Wheel Speed Circuit Open or Shorted
C1237H High System Supply Voltage
I no longer have any of the codes above except for C1233H and the new one, C1283H. Because these are history codes does this mean the fault is no longer present and if so why can't I extinguish the three DIC warnings for ABS, Active Handling and Traction Control?
The Helms Manual says an EBCM relay may have switched off these circuits when it sensed over voltage and will have to be reset with a Tech-2 or I can wait 100 ignition cycles and the EBCM will do that if it does not detect a recurrence. Am I on the right track before I start checking and cleaning all the grounds? 04 with 2K miles.
08-02-2012, 06:50 PM
#2
Le Mans Master
Thread Starter
History code are significant. They are the audit trail of a problem(s). Chances are that if you pull your codes before you shut off the engine you may have these codes showing as Current as well as History.
The C1233 says the Right Front Wheel Speed Sensor is experiencing a problem. Pull the wheel and inspect the wiring to the WSS for damage and pull apart the connector halves and look for damaged pins and/or corrosion. Clean/repair the wiring/connection as required.
The C1283 says that the steering wheel centering function has not completed. This could be caused by the Steering Wheel Position sensor going bad or because the steering wheel is not completely centered when driving down a straight road. This code can result in the anti-lock brakes being pulsed by the Vehicle Stability Enhancement System (VSES). Check the steering wheel position on a flat straight road. Should be centered. If not you may need a 4 wheel alignment. If the alignment is OK and the code persists then the SWPS is likely ready to puke.
Any or all of thes codes you experienced can be caused by a bad battery
The C1233 says the Right Front Wheel Speed Sensor is experiencing a problem. Pull the wheel and inspect the wiring to the WSS for damage and pull apart the connector halves and look for damaged pins and/or corrosion. Clean/repair the wiring/connection as required.
The C1283 says that the steering wheel centering function has not completed. This could be caused by the Steering Wheel Position sensor going bad or because the steering wheel is not completely centered when driving down a straight road. This code can result in the anti-lock brakes being pulsed by the Vehicle Stability Enhancement System (VSES). Check the steering wheel position on a flat straight road. Should be centered. If not you may need a 4 wheel alignment. If the alignment is OK and the code persists then the SWPS is likely ready to puke.
Any or all of thes codes you experienced can be caused by a bad battery
Now the $64,000 question I need the answer to right now (drum roll please...): Are there situations where old codes are present which cannot be reset without a Tech-II scanner? In other words, it cannot be done from the the car's on board diagnostics?
Thanks, Greg
08-03-2012, 01:18 PM
#3
Le Mans Master
Thread Starter
Yep, the procedure in the video is what I am doing. I realize if faults are present they will have to be corrected before I can successfully erase fault codes. The reason I am posting for help is the codes I have (C1233H and C1283H) look like history codes rather than current failure codes and if this is true I should be able to erase them, correct? If the codes had said C1233HC and C1283HC I would not have asked the original question that way. I would realize I have problems which will need to be located first. If I understand correctly what you are telling me is the fault code suffix is not necessarily reliable. I may in fact have a current problem which is being reported by the EBCM as past history and not current.
(Trying to understand... Is it the C5 or is it me?)
Thanks, Greg
(Trying to understand... Is it the C5 or is it me?)
Thanks, Greg
08-03-2012, 04:46 PM
#4
Le Mans Master
Thread Starter
H codes are an audit trail and some faults transition from HC to just H when you shut off the engine.
The codes are stored in the BCM and not the EBCM. EBCM is Electronic Brake Controller Module a component of the anti-lock brake controller.
Body Controll Module (BCM ) is the master computer in the car. There are many sensors or computers that report sensor information back to the BCM.
Any code (Status Info from a sensor) that is stored in the BCM can be cleared from the BCM memory where they stored by following the steps in the video. Once they are cleared you can go through the codes again and should see that there are "NO CODES".
As far as the suffix being reliable, when you pull codes they are "point in time". Although the video has you pull codes with the engine off, You can pull codes with the engine running and even while you are driving is your careful not to kill someone else while your attention is on other than driving.
Further since all of the sensor status info is being transmitted to the BCM over a serial data buss structure, electrical conditions such as ground issues, low battery voltage and damaged wiring can result is some pretty strange things being reported. Some codes can be set by just turning the ignition to the on position with out starting the car, Others can only be set after the engine has started and still others require the car to be driven before they are set. And to make it more complex, some codes are automatically deleted from memory after a relatively few ignition cycles while others require hundreds of ignition cycles without a reoccurrence of the fault before being automatically cleared..
These are some of the reasons you will see recommendations to "Clear all the codes, drive the car a bit and then pull the codes again. What codes come back are what you need to deal with".
The codes are stored in the BCM and not the EBCM. EBCM is Electronic Brake Controller Module a component of the anti-lock brake controller.
Body Controll Module (BCM ) is the master computer in the car. There are many sensors or computers that report sensor information back to the BCM.
Any code (Status Info from a sensor) that is stored in the BCM can be cleared from the BCM memory where they stored by following the steps in the video. Once they are cleared you can go through the codes again and should see that there are "NO CODES".
As far as the suffix being reliable, when you pull codes they are "point in time". Although the video has you pull codes with the engine off, You can pull codes with the engine running and even while you are driving is your careful not to kill someone else while your attention is on other than driving.
Further since all of the sensor status info is being transmitted to the BCM over a serial data buss structure, electrical conditions such as ground issues, low battery voltage and damaged wiring can result is some pretty strange things being reported. Some codes can be set by just turning the ignition to the on position with out starting the car, Others can only be set after the engine has started and still others require the car to be driven before they are set. And to make it more complex, some codes are automatically deleted from memory after a relatively few ignition cycles while others require hundreds of ignition cycles without a reoccurrence of the fault before being automatically cleared..
These are some of the reasons you will see recommendations to "Clear all the codes, drive the car a bit and then pull the codes again. What codes come back are what you need to deal with".
Regards, Greg
08-05-2012, 03:50 PM
#5
Le Mans Master
Thread Starter
I think we finally have it... one code remaining and it's current, C1233HC
RF wheel speed sensor. Unplugged and re-plugged the associated WeatherPak connector for a quick attempt but no go so guess I'll remove the wheel and check it with an ohmeter and for voltage when I spin the wheel. Wonder what the usual failure mechanism is on these?
Thanks, Greg
RF wheel speed sensor. Unplugged and re-plugged the associated WeatherPak connector for a quick attempt but no go so guess I'll remove the wheel and check it with an ohmeter and for voltage when I spin the wheel. Wonder what the usual failure mechanism is on these?
Thanks, Greg
08-05-2012, 06:21 PM
#6
Le Mans Master
Thread Starter
RF wheel speed sensor measures 1100 ohms and has voltage output on the AC millivolt scale when I spin the wheel. I can reset the C1233HC code which turns the warning lights out on the dash, drive the car and get the lights and code again within a few feet.
08-05-2012, 07:35 PM
#7
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St. Jude Donor '08
I think we finally have it... one code remaining and it's current, C1233HC
RF wheel speed sensor. Unplugged and re-plugged the associated WeatherPak connector for a quick attempt but no go so guess I'll remove the wheel and check it with an ohmeter and for voltage when I spin the wheel. Wonder what the usual failure mechanism is on these?
Thanks, Greg
RF wheel speed sensor. Unplugged and re-plugged the associated WeatherPak connector for a quick attempt but no go so guess I'll remove the wheel and check it with an ohmeter and for voltage when I spin the wheel. Wonder what the usual failure mechanism is on these?
Thanks, Greg
Theres a very good chance the FEMALE pins in the connector on the chassie are spread apart or damaged. Closely check the female pins and make sure that there not spread apart.
You can bend the tab back and male it make a better connection.
The output of the sensor is AC. If your getting an output, the sensor is good.
Bill
Bill
08-06-2012, 12:48 PM
#8
Le Mans Master
Thread Starter
Thanks Bill,
I removed the 30 inch long two conductor jumper harness for testing and it measured .2 ohms on both legs so I assume the jumper harness is OK. I also have output on a DMM AC millivolt scale at the jumper harness male terminals when spinning the wheel so I assume the RF wheel speed sensor is OK. I do have some spare male and female terminals so next on the list is checking the quality of the connections at the chassis harness connector. Is this the final check point for diagnosing C1233 or are there other connections beyond this one I might need to check. Really appreciate all the advice and guidance Bill and 8VETTE7!
Regards, Greg
I removed the 30 inch long two conductor jumper harness for testing and it measured .2 ohms on both legs so I assume the jumper harness is OK. I also have output on a DMM AC millivolt scale at the jumper harness male terminals when spinning the wheel so I assume the RF wheel speed sensor is OK. I do have some spare male and female terminals so next on the list is checking the quality of the connections at the chassis harness connector. Is this the final check point for diagnosing C1233 or are there other connections beyond this one I might need to check. Really appreciate all the advice and guidance Bill and 8VETTE7!
Regards, Greg
08-06-2012, 08:57 PM
#9
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St. Jude Donor '08
You can unplug the main connector on the EBTCM and read everything there.
BC
BC
08-11-2012, 09:49 AM
#10
Le Mans Master
Thread Starter
Car is Now Fixed!
Update:
I reset all the codes and most disappeared except for C1233HC and a new one, C1283HC (steering wheel off center) which was weird because this car has not ever been taken apart in any area and certainly the steering shaft has not been touched. Both C1233 and C1283 remained and persisted and because there was no EBCM failure code that I could see (such as the infamous C1214 or C1255) I launched into posting a lot of questions here and checking grounds and connections over the past years, etc. Since I don't need the car for transportation it was not particularily important that it get fixed right away so I just researched it in my spare time and tried things from time to time. At first I was convinced my problem was somewhere in the vicinity of the RF wheel speed sensor so I checked resistances in the wiring and connections and checked for voltage output on the AC millivolt scale and I had that. Finally after four years I called Jason Durr the Corvette specialist at City Chevrolet and he told me I was probably wasting my time trying to figure out the codes and just bring it in and get a new EBCM so I did.
Jason installed a new $1000 EBCM and informed me a few minutes later my car was fixed and he was right, now it is.
I reset all the codes and most disappeared except for C1233HC and a new one, C1283HC (steering wheel off center) which was weird because this car has not ever been taken apart in any area and certainly the steering shaft has not been touched. Both C1233 and C1283 remained and persisted and because there was no EBCM failure code that I could see (such as the infamous C1214 or C1255) I launched into posting a lot of questions here and checking grounds and connections over the past years, etc. Since I don't need the car for transportation it was not particularily important that it get fixed right away so I just researched it in my spare time and tried things from time to time. At first I was convinced my problem was somewhere in the vicinity of the RF wheel speed sensor so I checked resistances in the wiring and connections and checked for voltage output on the AC millivolt scale and I had that. Finally after four years I called Jason Durr the Corvette specialist at City Chevrolet and he told me I was probably wasting my time trying to figure out the codes and just bring it in and get a new EBCM so I did.
Jason installed a new $1000 EBCM and informed me a few minutes later my car was fixed and he was right, now it is.
08-11-2012, 03:34 PM
#11
Le Mans Master
Thread Starter
Because of all the EBCM failure reports I did ask if a secret warranty existed but sadly that's not the case or so I was told.
I was hoping they would let me have the old one so I could take it apart to see if I could find anything obvious or maybe send it off to find out what failed but they said they needed to return it for a core and I didn't want to pay to keep it. So... that's the story. Sometimes you just have to shell out some dough I guess.
I hope C6 electrical is improved because I have been thinking about a Z06.
I was hoping they would let me have the old one so I could take it apart to see if I could find anything obvious or maybe send it off to find out what failed but they said they needed to return it for a core and I didn't want to pay to keep it. So... that's the story. Sometimes you just have to shell out some dough I guess.
I hope C6 electrical is improved because I have been thinking about a Z06.
Last edited by Greg Gore; 08-13-2012 at 08:48 PM.