abs pump
11-04-2008, 03:21 PM
#2
Race Director
11-04-2008, 04:57 PM
#3
Burning Brakes
Member Since: Jan 2006
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....do you mean this?
BPMV - This unit has a pump and a series of valves. It is connected to the brake lines from the Master Cylinder and is then connected to the four brake calipers.
Under normal braking the BPMV valves are "open" so that brake fluid just passes straight through it and the calipers respond to your foot pressure on the brake pedal.
Should the EBCM decide it wants to take control of a caliper, say for ABS, the EBCM starts the pump in the BPMV and using solenoids it can change the valve layout so the EBCM can control brake pressure to that caliper. Using the pump and valves the EBCM can use the BPMV to decrease and increase brake line pressure to that caliper.
A C1214C code indicates that the relay inside the EBCM that powers up the BPMV pump and the solenoids in the BPMV has failed. Without this relay the EBCM cannot power up the BPMV components when needed. That is why the C1214 causes the loss of all the systems that require control of brake line pressure. You have lost ABS, Traction Control, and Active Handling.
. If you've got a problem with the BPMV. You could replace the BPMV yourself,but 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.
BPMV - This unit has a pump and a series of valves. It is connected to the brake lines from the Master Cylinder and is then connected to the four brake calipers.
Under normal braking the BPMV valves are "open" so that brake fluid just passes straight through it and the calipers respond to your foot pressure on the brake pedal.
Should the EBCM decide it wants to take control of a caliper, say for ABS, the EBCM starts the pump in the BPMV and using solenoids it can change the valve layout so the EBCM can control brake pressure to that caliper. Using the pump and valves the EBCM can use the BPMV to decrease and increase brake line pressure to that caliper.
A C1214C code indicates that the relay inside the EBCM that powers up the BPMV pump and the solenoids in the BPMV has failed. Without this relay the EBCM cannot power up the BPMV components when needed. That is why the C1214 causes the loss of all the systems that require control of brake line pressure. You have lost ABS, Traction Control, and Active Handling.
. If you've got a problem with the BPMV. You could replace the BPMV yourself,but 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.
11-04-2008, 05:01 PM
#4
Burning Brakes
Member Since: Jan 2006
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...or, do you mean this:
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. 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 you’re at it, this is a good time to upgrade the lug studs and add spindle ducts.
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. 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 you’re at it, this is a good time to upgrade the lug studs and add spindle ducts.
11-04-2008, 05:08 PM
#5
Racer
Thread Starter
Here
what im asking is this,,i took my ebcm out ,and i want to know if i can do something to see if the pump works when it is asked to,like can i put 12v on a lead on ot or something ?i sent mine off to be repaired and put it back in today and it showed 1242
Last edited by tonycorvettes; 11-04-2008 at 05:10 PM.
11-05-2008, 06:20 AM
#6
Burning Brakes
Member Since: Jan 2006
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read this from another post
.... I cleaned the ground connections and Nothing seemed to make a difference until I ran across the thread about a member who was clearing the code while driving and then slamming on the brakes to activate the ABS. I know when the car is started the system turns the ABS pump on and off and if the voltage readback is not high enough the code C 1242 is set and you get the messages. Since I do not have the interface connector for the EBCM I pulled the module away from the pump section. I measured the resistance of the pump motor from pin number 8 ((from left to right) (it is the first pin on the right hand connector))to the frame ground and it was in spec according to the manual. In my job we also use different size pumps for pressure and vaccum. When a pump is new or has been rebuilt it requires some break in period. If a pump has been used and off for some period of time it will also draw more current due to sediment build up and not being exercised. With this in mind I pushed a wire into pin 8 and ran it over close to the positve post of the battery so I could exercise the pump manualy. The pump came on the first time I touched the positive post but sounded sluggish. I exercised the pump about 6 more times for about 15 to 20 seconds at a time. I put the EBCM back on the pump section cleared the codes and so far the car has been running for one week now with only one message the first day after this procedure that message cleared on the next start by itself. If you try this use a heavy gauge wire and be aware the wire may get warm as you touch the battery. The pumps on these ABS units are most likely not broken in since they hardly run durring the life of the car. The car has been running fine with no more Traction control codes or Service ABS messages now for three weeks.
11-05-2008, 10:12 AM
#7
Burning Brakes
Hmmm, I wonder if if might be a good idea to occasionally drive the car in the rain (ugh) and do a few ABS stops and a few traction-control starts just to excercise the system. The other day the wife and I did just that in the new Caddy, just to understand how the system felt and performed - pretty awesome.
DG
DG
11-05-2008, 01:10 PM
#8
Instructor
Hmmm, I wonder if if might be a good idea to occasionally drive the car in the rain (ugh) and do a few ABS stops and a few traction-control starts just to excercise the system. The other day the wife and I did just that in the new Caddy, just to understand how the system felt and performed - pretty awesome.
DG
DG
