2001 GTP EBCTM removal

[govnor_77]

Can anyone walk me through the removal of my EBCTM on my 2001 GTP. Im havin the same trac control/ABS problems everyone else seems to have and I want to send it in to have it re-flashed.
Thanks

[BNaylor]

Your EBTCM module which is also part of the ABS pump/motor assembly should look like this below since it is a Bosch 5.3 ABS system. The module can be removed DIY separate from the ABS pump assembly. How did you determine the EBTCM module is the cause?


ABS Pump with EBTCM module - (1999 and up Grand Prix with Bosch 5.3 ABS)

[govnor_77]

[quote=BNaylor]Your EBTCM module which is also part of the ABS pump/motor assembly should look like this below since it is a Bosch 5.3 ABS system. The module can be removed DIY separate from the ABS pump assembly. How did you determine the EBTCM module is the cause?


I spoke with a mechanic who tried to erase it and said that the codes came right back (codes C0236, C0035). Do you think that this could be a misdiagnosis?

[richtazz]

C0035 - Left Front Wheel Speed Circuit Malfunction
C0236 - Rear Wheel Speed Signal Circuit Missing

These two codes indicate possible wiring or wheel speed sensor issues. Did he acutally check the wheel speed sensors in the hubs for proper continuity, or did he just clear the codes and assume because they came back it was the EBTCM?

[BNaylor]

What scanner was the mechanic using? These are generic ABS/Chassis codes and not GM specific which you can only get with a Tech II scan tool. I don't see the DTCs listed in the FSM. Therefore, not dependable for proper diagnosis of a GM ABS system.

[govnor_77]

Originally Posted by BNaylor

What scanner was the mechanic using? These are generic ABS/Chassis codes and not GM specific which you can only get with a Tech II scan tool. I don't see the DTCs listed in the FSM. Therefore, not dependable for proper diagnosis of a GM ABS system.

Im assuming that he was using a generic scanner and he though that it was the EBCTM because the codes kept returning. If thats not really the problem, what do you think it could be? Here is whats going on with the car:
1. Car pulls to the right and u can hear a rubbing sound (like the pad is rubbing at one point on the rotor). Wheel bearing has been replaced on that side in an attempt to correct this problem, but it still rubs.
2. Upon acceleration the car hesitates and seems to be unable to determine what gear to be in. And if I floor it the check engine light comes on.
3. Occasionally the tach will drop to 0 rpm while im driving and then reset itself when i turn the car off.
4. The steering seems really sluggish (especially at low speeds) and I get a good amount of vibration in the steering wheel (its like the power steering cuts in and out)

If you could give me your opinion on this I would greatly appreciate it. im in the Army and im getting ready to change stations and I need to be confident that this car will get me there. Thanks

[BNaylor]

Sounds like you have one than one problem. For the ABS/Traction Control system since you are looking for reliability to include safety and proper diagnosis you may want to consider having a GM dealer service department run a Tech II on it.

Was the wheel bearing job done by a shop or DIY? Maybe the brake portion wasn't done right. Sticking caliper. Improperly torqued axle nut. Another possibility is the EBTCM module which does sounds suspect is applying the brakes since the extended range traction control system which all GTPs have not only cuts off or reduces engine power but applies the respective brake to limit what it perceives as wheelspin. Normally caused by a bad wheel sensor at the respective hub, wiring or the EBTCM module.

The EBTCM module also controls the steering since it sounds like you have the Magnasteer (variable ratio steering). At low speeds the EBTCM module sends a signal to the actuator to make steering easier and at higher speeds firmer or more resistance for better road feel and control.

The tach dropping to 0 rpms is typically a flaky crank position sensor.

Since you have a '01 model GM issued a notice about a possible CAT convertor defect which can cause misfire and the engine to hesitate. So check into that possibility. Also, it will make the transmission look bad and cause shifting problems. We have the advisory notice posted at our Grand Prix Tips & Maintenance forum.

See link below:

Click here

[govnor_77]

[quote=BNaylor]Sounds like you have one than one problem. For the ABS/Traction Control system since you are looking for reliability to include safety and proper diagnosis you may want to consider having a GM dealer service department run a Tech II on it.

Was the wheel bearing job done by a shop or DIY? Maybe the brake portion wasn't done right. Sticking caliper. Improperly torqued axle nut. Another possibility is the EBTCM module which does sounds suspect is applying the brakes since the extended range traction control system which all GTPs have not only cuts off or reduces engine power but applies the respective brake to limit what it perceives as wheelspin. Normally caused by a bad wheel sensor at the respective hub, wiring or the EBTCM module.

The EBTCM module also controls the steering since it sounds like you have the Magnasteer (variable ratio steering). At low speeds the EBTCM module sends a signal to the actuator to make steering easier and at higher speeds firmer or more resistance for better road feel and control.

The tach dropping to 0 rpms is typically a flaky crank position sensor.

Since you have a '01 model GM issued a notice about a possible CAT convertor defect which can cause misfire and the engine to hesitate. So check into that possibility. Also, it will make the transmission look bad and cause shifting problems. We have the advisory notice posted at our Grand Prix Tips & Maintenance forum

I had a friend replace the bearing assembly (cause hes a certified mechanic), but all of the problems I stated occurred before the bearing was replaced. Im thinking about sending in the module to see if that helps and then move on from there. If its a wiring issue then Im really screwed because I have no idea where to start looking. Also, what does it cost to have a dealer check my codes?

[BNaylor]

You can do a visual inspection of the wiring starting at the back of each hub. Check all 4 wheels. Check specifically the electrical connector and look for any damaged wires from the connector wiring harness that runs along the control arms. Remove and reseat each connector. And then check the electrical connector at the EBTCM module.

Tech II diagnostics will vary from dealer to dealer. Best to call them to see what their rate is. Last one I had done on the ABS system was around $80. Also, they will check wheel sensor output as part of the testing. Once I got the valid DTCs I fixed it myself.