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Chris (aka-Moose)
Chris (aka-Moose), Technician
Category: Car
Satisfied Customers: 43903
Experience:  16 years of experience
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Power steering used to work intermediately, all of a sudden

Customer Question

Power steering used to work intermediately , all of a sudden stopped working on my car , tried replacing EPS module / PCM / TCM / BCM . nothing has helped. Took it to dealer they first said it was the EPS , we got it replaced still same problem , Now they are blaming harness , I changed that too still same problem. DIC does not display power steering message warning anymore.
Submitted: 2 months ago.
Category: Car
Customer: replied 2 months ago.
I tried to communicate with Maxidas , TechII , can't communicate to power steering module to pull any codes. I have tested for wire continuity from EPS to BCM , all seem fine. I dont know where to look anymore.
Expert:  Chris (aka-Moose) replied 2 months ago.

Welcome, I'm Chris (aka Moose) I prefer to work when others don't, I am here around lunch and after dinner till after midnight.

So all wiring to the EPS, power and ground and communication are fine?

Is the scan tool showing any U codes for module communication?

Now there is no steering assist at all?

Customer: replied 2 months ago.
No power steering at all at the moment , i have tried pulling several EPS/Motors off junk yards , that did not even trigger the power steering for a second atleast , All wires seem to be fine. As for codes like i mentioned earlier , scan tools cannot communicate with power steering module. Now the weird part that might lead us to the problem is that the DIC is not even displaying power steering warning anymore even though its completely shut off.
Customer: replied 2 months ago.
Eventually after involving NHSTA to look at my case , GM replaced my EPS motor/module which was a recall and that still did not help anything.
Expert:  Chris (aka-Moose) replied 2 months ago.

At the power steering module

  1. Red/black wire voltage reading?
  2. Pink wire voltage reading?
  3. Black wire resistance reading to chassis ground?
  4. Connector 2 pins 1-2 and 5-6 tan/black and tan wires. What are there voltage readings with the key off then with the key on?
  5. Connector 3 is red wire 5 volts and black wire ground?

These are the diagrams I am using if needed.

This is my 1st answer, but does not have to be my only answer. You the website and myself expect you to have a great experience with my help. Please let me know if you are pleased by selecting a star rating above or by replying and saying your pleased. Not rating or rating 1-2 stars does not benefit you nor me in any way. Follow up and reply as often and when needed, there is no extra charge to do so.

Thanks Moose.

Customer: replied 2 months ago.
Red ignition off - 0.532 v
Red ignition on- 9.02 v
Pink wire ign off -0.3 v
Pink Ignition on - 11.9 v
Ignition off
Tan/blk - 0.678 v
Tan - 0.678 v
Ignition on
Tan/blk 3.2 v
Tan - 2.9 vResistance to ground
No resistance3 connector ignition
Ignition off Red - 0.4 v
Ignition on - 4.9 v
Expert:  Chris (aka-Moose) replied 2 months ago.

Every reading is good except the 9 volt reading on the RD/BK wire. You should of gotten battery voltage there as well. Other than that all powers and grounds are good and communication wires are good. So the lack of communication has to be a faulty EPS module or the scan tool is not compatible.

Customer: replied 2 months ago.
i replaced around 4 EPS module/motor from a junk yard , no difference . eventually i took it to the dealer and they installed a new module/eps motor which is currently in the car and still doesnt work. doesnt sound like faulty module/motor to me.
Customer: replied 2 months ago.
Also if it was indeed a faulty EPS module/motor , should i not be getting a display on my DIC ? i used to get warning before when my power steering used to go on and off, all of a sudden everything just stopped , power steering and not getting anymore messages specifically power steering related.
Expert:  Chris (aka-Moose) replied 2 months ago.

The EPS module is not communicating with the car, that is why your not getting a DIC warning. I recommend taking the vehicle back to the dealer. Its now under warranty since they installed a new part. All you have to tell them is there new module will not communicate with the car or a scan tool.

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