I'll save you all the backstory, but my EPS light came on suddenly. Torque sensor was in perfect condition (I did remove, clean, test, and reinstall). I replaced the EPS module and now I'm back in business.

I did a teardown of my old module and found a couple things I thought might be worth sharing with the community.
The issue I have seen is the way that the transistors in the EPS module are installed. In the attached pictures, you can see the pins from the base of the module stick straight through the module. The pins have a copper contact pad at the top of each pin. The transistors that are mounted to the heat sink simply 'slide' over the pins and maintain contact through the pressure of the 'leg' of the transistor pressing against the copper contact at the top of the pin.
What I found is that all of the pins are at least partially pitted. This tells me that there was likely poor electrical contact. Not bad for 20 years of use, but we can do better. All the leads could be soldered directly to the pins with enough wire that essentially wraps around the whole transistor bay area. My main issue right now is that even the transistors (shown in bottom picture) are obsolete. Most of the places that I was able to source replacements from wanted minimum order quantities of 75+, and we only need 8 per unit. I did find a company that sells individual pieces and ordered enough to replace all the transistors. If there's enough interest, I'd consider posting a video of the process.

I already replaced my EPS with a salvaged unit and I'm back in business, but I'm intending on attempting to repair my original unit. If it works I'll just resell my 'used' unit as I've already verified it still works too!

After I get parts and test my unit, I'll come back with the results.


transistors attached to heat sink

main electronics bay pins

main electronics bay pins 2

 

This doesn't look like good engineering. Looks like that is a major failure point and I'm surprised any of the originals still work after 20+ years. How did your repair work out?

 

How did I miss this post? Yes, definitely make a video.

Suggestion. Become the ps ecu guru. Offer rebuilt units with your update. Look for a couple of dead units to resurrect, then start a rebuild core service.

Someone buys your rebuilt, sends you their core to get core refund. You rebuild that one, and so on. Just need a couple of them ready to go to get started.

Come up with a test bench of whatever stock systems are needed to verify working unit, to speed final step in rebuild.

These cars are getting older, and owners richer. There will be a need for this service, which will become more desperate as time goes on. All the units are probably nearing end of life due to pitting and loss of enough contact to keep working. Timing to start such a service might be perfect.

You could eventually branch out to other components. Not sure why no one has started a rebuild service for steering sensor. An easy diy clean and regrease, but many people would rather just bolt on working parts. Or have a mechanic do that.

Could also rebuild starters, alternators, etc.

 

Mine is still perfect after 23 years so I'm not touching it and hope to never have to but being realistic, this pin issue might come up to bite me, who knows...touch wood/knock on wood, etc, etc. Please do that video! Definitely keen to see you do that.

 

Welp, been roughly 4 months without a peep...and that was his only post...so....

If anyone has a busted EPS unit I'd be more than happy to try this out for the community. I used to do electronics for a living, so soldering, wiring, etc is like a second nature to me.

 

I have EPS code 32. Just found a salvaged one and will be installing the replacement this weekend and I hope it fixes the problem. I hate to toss the old one if it does fix the problem as these parts are limit resources. I too am hoping there is someone out there who can fix this as once this is no longer manufactured.

 

So how did the EPS module repair go ?

 

Installation was simple, remove the battery, then 4 bolts (carefully tighten manually).

Took it for a drive and so far so good, but I don't have a diagnosis computer to see if the Code 32 had disappeared. Will update if I can find one and rescan for code.

 

Thank you. I was actually asking if anyone had tried to repair the module.But good to know your module fixed it.
I have a similar problem in my 04. Went to do a u-turn and part way through lost power steering.
EPS light goes out when I restart the car, until I move the steering wheel at all. Then instant EPS light.
Checking code produces 32 & 23. Factory manuals point to EPS ECU after checking wire voltages, and wheel signals.
I would really like to confirm the module is bad before acting on replacing it. Anyone else have insight on these symptoms ?
TIA

BTW from what I read so far, you can jump OBD pin 4 to 9, or ground the brown wire on EPS ECU harness,
to get the EPS light to blink out any stored codes. You can also pull the "backup" fuse for 1 minute to reset stored codes.

 

Which fuse are you referring to? I need to reset the EPS codes and I'm having a heck of a time tracking down a PGM scanner to clear them.