Electric Power Assist Steering Problems List Grows

[ADM PERFORMANCE]

Just wanted to update what I have been monitoring on ELECTRIC POWER ASSIST STEERING ISSUES with 2012-2015 CAMAROS.

A true fix needs to happen before more people die.

http://www.usatoday.com/story/money/...?showmenu=true

EPAS PROBLEMS IN CAMAROS

Post and Threads

1.http://www.camaro5.com/forums/showthread.php?t=368931

2.http://www.camaro5.com/forums/showthread.php?t=367987

3.http://www.camaro5.com/forums/showthread.php?t=402656

4.http://www.camaro5.com/forums/showthread.php?t=397829

5.http://www.camaro5.com/forums/showth...light=steering

6. http://www.camaro5.com/forums/showth...light=steering

7.http://www.camaro5.com/forums/showth...light=steering

8.http://www.camaro5.com/forums/showth...light=steering

9.http://www.camaro5.com/forums/showth...=225187&page=4

INFOMATION:

Service Information
2012 Chevrolet Camaro | Camaro VIN F Service Manual | Document ID: 2831254
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#PIC5643A: PQC Part Restriction - Electronic Power Steering (EPS) Service Steering Message Displayed And Increased Steering Effort - (Apr 16, 2012)

Subject:

PQC Part Restriction - Electronic Power Steering (EPS) Service Steering Message Displayed And Increased Steering Effort
Models:2012 Chevrolet Camaro ZL1
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This PI was superseded to update department contact information. Please discard PIC5643.
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The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.

Condition/Concern:
The DIC may display "Service Steering" in combination with an increase in steering effort and standard diagnostics may lead to steering gear replacement. As of 03/30/2012 Electronic Power Steering P/N 22848599 has been placed on restriction through PQC. This part restriction will allow Engineering to evaluate the fault while the steering gear is in the vehicle and prior to any repairs.

Recommendation/Instructions:

Important: Do not perform a Clear DTCs function.
Retrieve any stored DTC information from the Electronic Power Steering module. If any of the following DTCs are set (history or current) in the EPS module or you are unable to diagnose the cause DO NOT CLEAR DTC(s), STOP FURTHER SERVICE ACTIVITY, complete the questionnaire below and contact PQC for further action.•

DTC C0569
DTC C0475
DTC C056E
DTC C0545
DTC C056D
DTC C055C
DTC C0544
For all other concerns where the above DTCs are not set, follow the published service procedures to complete the repair. Should the repair require steering gear replacement, contact PQC to review the diagnosis and order the part.
Please complete this questionnaire prior to contacting PQC.
Customer’s concern:

What is the customer’s description of the concern?

How many times did the customer indicate the issue occurred?

During which of the following driving condition(s) did the customer have a steering concern?

Low Speed turn Y/N

Straight-away Y/N

On a rough road Y/N

Was the concern temperature related? Y/N

Was the concern weather related? Y/N

Did the concern occur during an engine start (cranking)? Y/N

Please list any other conditions (if applicable) when the concern occurred.

What are the current and/or history DTCs?

Is the vehicle still exhibiting the customer concern? Y/N

Has the vehicle been modified with any aftermarket accessories or options? Y/N

What SI document number was used during the diagnosis?

Have the wires/harnesses been checked for proper routing and free from damage, stretch, pinch, etc.? Y/N (If no, perform this inspection prior to calling PQC.)

Have the wires been checked for any damaged, loose, or disconnected connectors? Y/N

(If no, perform this inspection prior to calling PQC)

Have any wire connectors or terminals been disconnected or loosened and then re-torqued? Y/N

Has the EPS supply voltage been checked on both sides of the EPS Fuse? Y/N

IF Yes, what was the voltage with ignition OFF? ___ Volts

(If no, you need to check and record voltages with ignition OFF prior to calling PQC. This fuse is not accessible; it is molded into the EPS power cable between the Battery Positive Junction Block and the EPS motor. Measure voltage at both ends of the EPS power cable)

Have you made any other observations or have any recommendations of what may be causing this concern?

Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.

GM bulletins are intended for use by professional technicians, NOT a "do-it-yourselfer". They are written to inform these technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions, and know-how to do a job properly and safely. If a condition is described, DO NOT assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See your GM dealer for information on whether your vehicle may benefit from the information.

WE SUPPORT VOLUNTARY TECHNICIAN CERTIFICATION
© 2012 General Motors. All rights reserved.

Customer Comments from this forum:

Boy this could get old.
We were just getting home from a hour drive and just as we get to the house
bamm!!!!..No p/s this would not be too safe if my girlfriend is driving it.
I let it sit for for just a little while and we out and it worked again.
The way it came back as I started it was like it had a bad connection and came to life just as the car started.
Will call the dealer to see if they have seen this yet here in phoenix AZ


Now that I get the paperwork back it says ".7 hr. Diagnostics of DTC C0475\00 lead to PIC5643E. Per PIC5643E regrogram P/S control module. Clear DTC's and verify no DTC's reset at this time. Warr code 313E3"

[NW Sam]

Is mileage an indicator?
When do people have these issues, on long drives?
Is it time or temperature related?
What about loose connections?
Could it be someone at the manufacture pulling the power steering by the wires?

[2013 ZL1 #7860]

I thought this was determined to be a grounding lug issue in some cases?

[ADM PERFORMANCE]

The more I wrap my head around it the more I agree that it is the ground location and size.

The RED 12v+ wire is roughly 6 ga x 32"' long with what appears to be a very robust connector at the power distribution/jump start block mounted to the shock tower on the driver side. The bolt that holds this power lug is 8mm in diameter (same as your starter power inlet bolt) with a 13mm hex outside diameter that can be torqued between 17-29 ft lb give or take. Dam good connection if you ask me.

The BLACK 12v- wire is roughly 6 ga x 48" long with what appears to be a very robust connector at the end that grounds to the side of the car near the Intake. The bolt that grounds it is 6mm in diameter (the diameter of most grounds on the car that ground low current devices like lights, fuel pumps injectors etc.) with a 10mm hex outside diameter and small washer built in flange to aid in surface area.This bolt has a torque rating of 3-12ft lb give or take.

The codes that we are seeing are 90 percent voltage related, I have listed them here -

I have a list of common codes with descriptions:

C0475-00 Power Steering Motor Circuit

C056D-39 Electronic Control Unit Hardware - Internal Malfunction

C056D-3C Electronic Control Unit Hardware - Internal Communication Malfunction

C056D-3B Electronic Control Unit Hardware - Self Test Malfunction

C0800-12 Control Module Power Circuit - Low Input


The math:

6 ga wire 32" long at 125 amps voltage drop is 1.9 percent not factoring in connection point size.

6 ga wire 48" long at 125 amps voltage drop is 3.3 percent not factoring in connection point size.

When electrical current moves through a wire it must surpass a certain level of contrary pressure. If the current is alternating, such pressure is called impedance. Impedance is a vector, or two-dimensional quantity, consisting of resistance and reactance (reaction of a built up electric field to a change of current). If the current is direct, the pressure is called resistance.

All this sounds terribly abstract, but it's really not much different from water running through a garden hose. It takes a certain amount of pressure to push the water through the hose, which is like voltage for electricity. Current is like the water flowing through the hose. And the hose causes a certain level of resistance, depending on its thickness, shape, etc. The same kind of thing is true for wires, as their type and size determines the level of resistance.

Excessive voltage drop in a circuit can cause lights to flicker or burn dimly, heaters to heat poorly, and motors to run hotter than normal and burn out. This condition causes the load to work harder with less voltage pushing the current.

Experts say that voltage drop should never be greater than 3 percent. This is done by selecting the right size of wire, and by taking care in the use of extension cords and similar devices.

The direction I am going with this is very simple - This wire that grounds this power steering rack is to small for its length and load it is expected to carry as well as its connection point size.The wire should have a shorter path to its grounding point,it should have a larger lug that has a higher torque rating and surface area.

Its obvious that the engineers put this part right on the edge of failure yet they made the voltage window it operates within super sensititive to triggering a code and going into limp mode(shut down mode).

For Liability Reasons we will not be offering a fix for this, only raw information of how it works and ideas that can aid in making it better.

[scdrj]

All of this, plus you have not even added in all the potential resistance before you hit that grounding spot. Further, consider that is the source as DC current flows from Neg to Pos, not Pos to Neg. Not that it matters here. There is more going on than meets the eye, but the connection is apt to be more of a problem. If the PS pulls 125A continuous, thats crazy. Anytime you have that kind of pull, there will be heat. Heat means more resistance. More resistance means more voltage drop. More voltage drop will require more current to maintain the same power level. I'm sure the engineers are not stupid. There is more to it.

[Z4me]

The power steering going out on my car seems to be heat related. I drove a couple months ago to the emmissions testing place which was about 40 minutes away. The temp reached around 98 and on the way back the steering went out. I have driven the car probably another ten times since then with no issues. The only differance was the temperature being cooler during those times.

[jayno20]

Anyone having this issue with a 2014 that has NOT had that ground bolt messed with?

[ADM PERFORMANCE]

One of the problematic cars we have seen this with has made a modification on his own under our theory.

He shortened the black 6ga power wire AND CRIMPED A NEW CONNECTOR TO IT and moved it to the block bolt were the rear of your alternator is mounted( 10mm bolt diameter).He then Grounded the block on the passenger side with a larger 1/0 gauge wire to the block and factory ground point.

Reported back with no issues so far and no more SERVICE STEERING MESSAGES

[Dimitrim]

I had a 2013 2SS automatic I drove for about a year. It was my DD, 80 miles a day. In the year I drove it, I got the service power steering message about 8 times. Dealer could not figure it out.

[Sakudog]

Originally Posted by ADM PERFORMANCE

One of the problematic cars we have seen this with has made a modification on his own under our theory.

He shortened the black 6ga power wire AND CRIMPED A NEW CONNECTOR TO IT and moved it to the block bolt were the rear of your alternator is mounted( 10mm bolt diameter).He then Grounded the block on the passenger side with a larger 1/0 gauge wire to the block and factory ground point.

Reported back with no issues so far and no more SERVICE STEERING MESSAGES

Any updates here? My car has gotten the EPAS message twice, always on startup and not during driving.

Typically I kill it and restart it and the message goes away, but I'm GAME to augmenting the ground if you guys NEVER get the EPAS error again. Please let us know, I know it is early.

Thanks for your support on this!!!

[ADM PERFORMANCE]

Originally Posted by Sakudog

Any updates here? My car has gotten the EPAS message twice, always on startup and not during driving.

Typically I kill it and restart it and the message goes away, but I'm GAME to augmenting the ground if you guys NEVER get the EPAS error again. Please let us know, I know it is early.

Thanks for your support on this!!!

The car in question has had no other problems since.

[vicnkathy]

I showed your theory to an electrical engineer and he is in complete agreement.

[Sakudog]

Originally Posted by ADM PERFORMANCE

The car in question has had no other problems since.

Thanks ADM!

[Crash76]

Why would you put a power wire to the block?