Tricky ABS problem [Archive] - GrandAmGT.com Forum

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xzeromark
05-25-2004, 01:44 PM
Ok, my BRAKE and ABS light are on in my car. I did all the normal check's (fuses, abs sensors). Now I got it scanned and I get a "no communication" error with my abs module. (at this point if you are scratching your head and saying "what!?" then turn away.) Anyone know which what sends or picks up the singnal for ABS, is it the BCM or the regular powertrain computer? And from there what can I do to try to fix this, or atleast have a great trouble shoot method to figure out if the ABS Module or computer is fired?

Good luck

Jagey
05-25-2004, 01:49 PM
personally I prefer driving cars without ABS. It feels like there is more control, even though there probably isn't.

Dan00GPGT
05-25-2004, 02:00 PM
Done with ignition off.

Assuming you can talk to the other devices on your data bus (BCM, etc) then you need to check the ABS BATT 10 amp fuse as well as the ABS IGN fuse (also 10A).

If that's ok, check the black wire going into the EBCM for a high resistance. It should be less than 2 ohms from the EBCM connector pin D to the chassis. Disconnect the harness to the EBCM to test this.

If that's ok, check terminal 13 on the EBCM harness for greater than 10 volts. Disconnect the harness to the EBCM to test this.

Turn the ignition switch to ON and measure the voltage at terminal 4. It should be greater than 10 volts. Disconnect the harness to the EBCM to test this.

Measure the resistance between terminal 12 of the EBCM connector and terminal 9 of the DLC connector. The DLC connector is the port where you plug the scan tool in. This checks that the EBCM has continuity to the DLC connector. You should have less than 2 ohms of resistance.

Measure the resistance between terminal 12 of the EBCM and ground. You should have infinite resistance. Repeat this test for terminals 4 and 13 of the EBCM.

If none of that solves it then it very likely is a bad EBCM. The EBCM and BCM can talk independently on the data bus so nothing is talking for it. IT is talking.

action
05-26-2004, 05:36 AM
Check each wheel to make sure there are no wheel sensors damaged or missing. I had my ABS light come on only to find that the wires for the drivers side front ABS sensor had been ripped clean out of the hub, likely by ice.

lee
05-27-2004, 12:22 PM

lee
05-27-2004, 12:28 PM
ABS, TRAC & SVS lites all on. Bad sensor front right wheel. When I replace the hub assy with the sensor do the lites clear on the dash automatically and will any error that exist in the comput clear at this time. What next? Hope you don't mind my hanging on your thread XZEROMARK..

action
05-28-2004, 06:40 AM
yes they'll clear.

Hexx
05-28-2004, 06:45 AM
yes they'll clear.

Will they? I guess I should get my car checked out then. After installing my springs my ABS, Trac Off, SES lights came on (and are still on). I realized I unplugged the rear ABS sensor....so I plugged it back in and unplugged my batt for 30 mins. The lights are still on and have been for 3 weeks now :(

Dan00GPGT
05-28-2004, 08:05 AM
Will they? I guess I should get my car checked out then. After installing my springs my ABS, Trac Off, SES lights came on (and are still on). I realized I unplugged the rear ABS sensor....so I plugged it back in and unplugged my batt for 30 mins. The lights are still on and have been for 3 weeks now :(

They will clear after x number of driving cycles I believe. I imagine after 3 weeks yours should have cleared. You should get that code checked again to be certain it's not the same thing.

lee
05-28-2004, 08:53 AM
Hey guys thanks much for the quick response. After I replace the hub assy (with sensor) I'll let you know the results. Again I want to let XZEROMARK thanks for letting me hang on your thread.

lee
05-29-2004, 12:53 PM
replaced the hub assembly (incl ABS Sensor). When the ignition was turned on and started the car, the ABS, SVS, TRAC lights all cleared. Thanks for all the advice and answers.
:wave:

Intuit57
08-26-2004, 10:30 AM
lee, have the lights stayed off? I just had hubs replaced 2 days ago and now the lights came on again...? thanks

spydave00
08-26-2004, 09:28 PM
Hey guys,

I had the same problem. Replaced the hub assembly and the codes clear for a bit and then came back on the next day. It ended up being the wiring was lose so this seems to be a common problem. I mean I replaced the assembly and I did not have to so it cost me some bucks although my car drives smoother now but it is the WIRING, check it out good!

Intuit57
08-27-2004, 07:26 AM
Thanks Spyday...I appreciate having some info to help these guys(mechanics) out when they look at my car in a few minutes! :)

2000 GT Coupe
04-26-2009, 01:37 AM
Ok, my BRAKE and ABS light are on in my car. I did all the normal check's (fuses, abs sensors). Now I got it scanned and I get a "no communication" error with my abs module. (at this point if you are scratching your head and saying "what!?" then turn away.) Anyone know which what sends or picks up the singnal for ABS, is it the BCM or the regular powertrain computer? And from there what can I do to try to fix this, or atleast have a great trouble shoot method to figure out if the ABS Module or computer is fired?

Good luck

Done with ignition off.

Assuming you can talk to the other devices on your data bus (BCM, etc) then you need to check the ABS BATT 10 amp fuse as well as the ABS IGN fuse (also 10A).

If that's ok, check the black wire going into the EBCM for a high resistance. It should be less than 2 ohms from the EBCM connector pin D to the chassis. Disconnect the harness to the EBCM to test this.

If that's ok, check terminal 13 on the EBCM harness for greater than 10 volts. Disconnect the harness to the EBCM to test this.

Turn the ignition switch to ON and measure the voltage at terminal 4. It should be greater than 10 volts. Disconnect the harness to the EBCM to test this.

Measure the resistance between terminal 12 of the EBCM connector and terminal 9 of the DLC connector. The DLC connector is the port where you plug the scan tool in. This checks that the EBCM has continuity to the DLC connector. You should have less than 2 ohms of resistance.

Measure the resistance between terminal 12 of the EBCM and ground. You should have infinite resistance. Repeat this test for terminals 4 and 13 of the EBCM.

If none of that solves it then it very likely is a bad EBCM. The EBCM and BCM can talk independently on the data bus so nothing is talking for it. IT is talking.

I know this is a really old thread, but I am having the exact problems as the OP and I did all the checks that are listed and everything is ok except terminal 12 to ground is not infinite, it is 1922 then changes to infinite, I have put 4 different ecbm's in every time they communicate fine until I try starting the car then there is no more communication.
Also the fuse abs/evo #36 under the hood only gets about 3 to 9 volts and the relay is continuously clicking
and input would be apreciated.