If the rack is bad, that'd just be the torque sensor, no? You might be able to get more info from HDS.

 

I suspected the rack could be it. That’s why I checked the DC motor for resistance. A couple of times I also got DTC 5-1 Open Motor Circuit. The service manual recommends checking the fuse and harnesses for continuity between the battery and motor. I found no issues. If not, just like with 32-1, the manual recommends trying a known good EPS module. It’s possible the used EPS module is bad. Finding used modules for AP2s is difficult.

 

I am about to pull my EPS module out. Has there been any progress on a fix? I really don't want to roll the dice on a salvaged unit, since its life is unknow.

 

I was finally able to desolder the board. The small pins in the middle gave me the most trouble. I don't see anything obviously damaged on the board so replacing the main MOSFETs still seems like the most prudent course of action. As expected, the holes in the middle of the housing line up with the heat sink mounting bracket so that is definitely the production process confirmed. They mount the MOSFETS and large heatsink and then solder the board on. I'm just not sure how I want to attach the new MOSFETs. I am fairly certain they were spot welded on after finding no solder residue. There are small hobbyist welders out there (typically used for making battery packs it seems) but I don't know if those would have the power to attach these. Anyone have any experience here?

 

Well pooh... I did not know you had resumed work on the EPS.
My 04 had gone out, which is what initially brought me to the posts on tear down. I was able to rule out other causes with enough confidence to buy an 05 used replacement, which fixed my problem.
Then I disassembled the old one looking for the failure.
I did a visual, then checked the MOSFETs which were good, the 2 surface mount fuses, voltage regulator, the relays, large caps, most diodes, a few small transistors.
No luck. I set it aside in favor of other needs. I felt there was an increasing chance the problem was in one of the processors, but had no way to easily verify without some docs.
To go further I think I would need to bench the board and simulate the other inputs.

 

Well...now there is a company who will repair these....$250. Prob same price as a used one?? (not my Company)

Honda S2000 EPS Unit Repair | Steering Services

 

Interesting...did you desolder the board to gain entry? If so, do you have any pictures of the MOSFETS assembled to the pins?

 

That's excellent news! I'll have to inquire with them if they can resurrect my butchered unit lol

 

Sorry I meant to get back to this sooner, and post your requested pic.
Pic showing the pins, it appears they may be spot welded, but could be soldered to repair.
Bobby

 

The pins on 3 sides have to be unsoldered to removed the circuit board and access the lower chamber.