How to check ABS pump?
 

Started when I got "TCS NO COMM." message, ABS light was permanently ON. I re-soldered ABS module relay, cleaned ignition switch but nothing helped. Before I remove all the unit and send it for the repair I wanted to check if ABS pump even works when plugged to external power source. Do you know how to do that and where to apply +12V so the motor could run?
Or any other ideas how to check the system?
Thanks

The codes I got (all related to ABS/TCS):
10 PCM = P1571 HC
28TCS = No Comm
58 SDM = U1040 HC.

No Comms mean it's not even "talking" on the can buss. Test the power and ground points to the module. Check for damaged wiring. This has nothing to do with the commonly repaired relay issue. Might not even be fixable.

Just powering the motor won't tell you if the electronics work.

I know, just tried what I could in my desperation...
I have checked wiring, there is ground, constant 12V and ignition swiched 12V in EBCM plug. Everything starts to indicate module damage. Any other suggestions?

thanks

Are you sure the is NOT a fault with in your 'wheel speed sensors" ? This is the most common fault for most ALL ABS codes on cars with traction control------
The wheel speed data is used by both the TC and the ABS systems---The TC uses the data to prevent the rear wheels from spinning on a hard launch---and the ABS uses the data to prevent the wheels from skidding on a hard stop---
Have you checked the sensors ? Pigtails ?

I have checked every sensors - raised the car, unplugged it and checked resistance/voltage changes when rotating the wheel. Hopefully my method was good.
But I think that NO COMM. code cannot be caused by wheel sensor, it is rather circut issue and system check does not result in receiving voltage when turning the ignition on .

I had the same codes awhile back. I had to have the pump replaced due to the oil inside was so gummed up after 15 years it caused a overload with the EBCM when it activated it. Now I activate the system once a month. Just my 2 cents what happen to me.

Yes, you are correct.

Here are a few other items to check. Did you check the voltage of your battery with the engine off--below 12.5V and misc problems occur. Another item to check is the ignition switch, if you pull the switch, Bill Curlee has an item in the stickies about cleaning it. Usually the non-Comm codes can be battery or ground related, also you have an air bag non-comm code did you check the chassis grounds for those items, they can cause intermittent electrical problems.

Thanks, however grounds are cleaned, ignition switch cleaned - was dirty as hell. Battery replaced last week. Didn't help.

One more thing to look at---In order to get full communication thru your OBD2 port you must make sure the fuse is not blown
GM hides thr ODB2 fuse on the cigarette lighter circuit make sure your cig lighter fuse is not blown
This often happens with phone chargers etc--