Electric power steering issues

[abmobil]

Sadly my 17 GT was in a wreck November 2024. Shop did a good job with body work but I still don’t have the car. EPS rack was damaged. They replaced and new rack wouldnt communicate. They took it to a ford dealer who replaced rack again. Same problem.

Car is boosted. I thought maybe the tune was causing the issue. I put the stock tune on it. Same problem. They are now looking into replacing the harness going to the EPS. Anyone else ever go through EPS issues like this? Thanks for any feedback.

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[Skye]

I wouldn't be to concerned right now. IDK why the dealer replaced the rack a second time; maybe they saw something in the repair installation they didn't care for.

Moving to the harness seems logical. You had an accident bad enough to damage the original rack. With the density and amount of wiring that exists in vehicles today, it's not surprising some of the wiring or connectors would have been damaged.

Attached is a diagram. It's not necessarily your Model Year. The harnesses throughout the car are often segmented. So instead of replacing all the wiring under the hood, they replace a portion of the wiring.

The car is at the dealer; that's a good thing. They'll have everything they need to repair it.

Good Luck.

 

[abmobil]

I wouldn't be to concerned right now. IDK why the dealer replaced the rack a second time; maybe they saw something in the repair installation they didn't care for.

Moving to the harness seems logical. You had an accident bad enough to damage the original rack. With the density and amount of wiring that exists in vehicles today, it's not surprising some of the wiring or connectors would have been damaged.

Attached is a diagram. It's not necessarily your Model Year. The harnesses throughout the car are often segmented. So instead of replacing all the wiring under the hood, they replace a portion of the wiring.

The car is at the dealer; that's a good thing. They'll have everything they need to repair it.

Good Luck.

I was told they thought the first new replacement rack had a defective module in it. So that’s why they replaced it. I am a little concerned about it being at the dealer lol because the body work was done well but Ford has already managed to scrap the bottom of the back bumper. Looks like the backed it into a curb.

 

[Skye]

Whatever process you've been using, however you've been working with all the different parties, I'd continue to press on with that. You've documented this much of the dealer thus far. I'd keep checking in, monitoring, etc.

Once they have the steering repaired, that's when I'd bring up any new or additional concerns. The scrape for example.

If you continue to loose faith in the dealer, reach out to the insurance company and explain yourself. Discuss options. Depending on where you live, maybe there's another location the car could be sent to.

Ultimately, do not sign for or accept anything unless you're satisfied. The dealer might not repair the scrape, but there should be a note, acknowledgement or something to the other parties confirming it happened on their watch. While it might not be immediately settled, the documentation is something to be given to the insurance company, an item they can then work before final acceptance of the car and everything is closed out.

 

[Cobra Jet]

I had created this technical reference thread for the EPAS unit a while back, which contains a lot of info for the EPAS/PSCM. There may be some beneficial info in that to help you and your Shop doing the work:
https://www.mustang6g.com/forums/threads/s550-epas-pscm-tech-accumulation.160616/

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The rack does need to be the same part # when the car was built, otherwise they’re going to have programming issues. If trying to use a rack that was not the same as the “as built” unit the vehicle came with it does need programming. There are several racks used between the S550 platforms and they are not just “swap in swap out” like racks from years ago….

Also check the threads in that link RE: the harness issues.

 

[abmobil]

I had created this technical reference thread for the EPAS unit a while back, which contains a lot of info for the EPAS/PSCM. There may be some beneficial info in that to help you and your Shop doing the work:
https://www.mustang6g.com/forums/threads/s550-epas-pscm-tech-accumulation.160616/

—

The rack does need to be the same part # when the car was built, otherwise they’re going to have programming issues. If trying to use a rack that was not the same as the “as built” unit the vehicle came with it does need programming. There are several racks used between the S550 platforms and they are not just “swap in swap out” like racks from years ago….

Also check the threads in that link RE: the harness issues

Do you think it matters if the stock tune or VMP tune is on the car as far as being able to program new rack or get it to communicate? I reflashed it to stock and I am concerned with the dealer needing to start or move it on the stock tune. VMP and Lund heavily advised against that.

 

[Cobra Jet]

I am but sure how the EPAS programming is or is not associated with the main PCM. If a EPAS reflash is needed by the shop, I’m not sure if that reflash has any bearing on the main PCM and if it too gets reflashed simultaneously, separate of the EPAS reflash, or isn’t affected at all.

I think @engineermike might be able to offer some insight to the reflash question.

 

[engineermike]

The dealer can diagnose and reflash modules without reflashing the pcm cal. Whether they will or not is another question.

 

[K4fxd]

The dealer can diagnose and reflash modules without reflashing the pcm cal. Whether they will or not is another question.

I do know the rack needs the VIN number to work and I do not know, if the PCM is scrambled, if it will communicate. So I "THINK" an unscrambled tune needs to be loaded for a successful re-program.

 

[engineermike]

I had a similar issue with a warranty airbag on a Whipple car. The dealer had to manually enter something into their device. Whipple actually had to show them how to do it.

 

[K4fxd]

I had a similar issue with a warranty airbag on a Whipple car. The dealer had to manually enter something into their device. Whipple actually had to show them how to do it.

Whipple doesn't scramble their tunes. Makes sense to me the PSCM would need an unscrambled PCM first time communicating.

Again this is just me speculating.

 

[abmobil]

Well after 2 new rack installs ford decided to order a harness. Ford supposedly doesn’t make the harness anymore. Order got kicked back twice according to body shop. A dealer tech was able to repair the existing harness in one day. Car sat at Ford for the entire month of February over this. And 3 months prior for the rest of the repairs.

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