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Upon closer inspection I can't be sure that the MOSFETs aren't soldered on. The 4 holes next to the body pins are right over the screws that mount the MOSFET bracket. These are either relief for the head of the screws, or access to tighten them down during assembly.
Is it possible that the metal trace panel that has the "body pins" in the EPS module can be easily removed? I'm wondering if that metal trace panel maybe was originally separate and the body pins soldered to the MOSFET pins as an assembly on the heat sink side. Then that assembly was placed into the EPS main module and the trace panel making electrical connection with friction? I can't quite tell if this is possible from the photos.
It looks like the pins come through the side and are then soldered or welded to the lead frame in various places. I'm still puzzled over how the original assembly process would have worked.
Oh, excellent spot about those four holes. I think that confirms these are soldered first, then the access holes are used to secure the MOSFETs to the heat sink surface with the four screws and hold down bracket. The question is how is that step done? Can you see if this entire unit can somehow separate from its plastic enclosure? (The red circled area). If this could separate, then after you do the soldering, you secure the heat sink unit with the four screws via the backside of this board and then drop it back into the plastic enclosure??? Hmmm....interesting thread!
Maybe these were soldered in place in a unique way. Like solder machine applied to mosfet legs in, say, an even coat.
Then after inserting, heat applied to melt that solder just enough to augment electrical conductivity.
Just thinking of something that would leave minimal actual solder (compared to typical through hole), but still enough to make removing them a leg contorting mess.
Oh, excellent spot about those four holes. I think that confirms these are soldered first, then the access holes are used to secure the MOSFETs to the heat sink surface with the four screws and hold down bracket. The question is how is that step done? Can you see if this entire unit can somehow separate from its plastic enclosure? (The red circled area). If this could separate, then after you do the soldering, you secure the heat sink unit with the four screws via the backside of this board and then drop it back into the plastic enclosure??? Hmmm....interesting thread!
Yea no way to remove just that section. The lead frame is routed through the plastic in several places and the plastic body is one big molded piece.
Maybe these were soldered in place in a unique way. Like solder machine applied to mosfet legs in, say, an even coat.
Then after inserting, heat applied to melt that solder just enough to augment electrical conductivity.
Just thinking of something that would leave minimal actual solder (compared to typical through hole), but still enough to make removing them a leg contorting mess.
Yea I think this is what we're seeing. Something like an even tin coat on the entire copper substrate that they then just cut and bent into these various shapes. You can see witness marks where some kind of soldering iron/clamp was applied to make the connections
Quick update. I purchased a used A04 version steering module off fleabay and it seems to have solved my problem (more testing will be required as my old module did sometimes spring back to life, but never for long). At least this gives me confidence I didn't destroy a perfectly good module. This answered a nagging question that the forums didn't seem to have an answer to in my cursory searching. My 2007 car came with an A05 module and was worried that A04 wouldn't work with it. This fear turned out to be unfounded.
The more I examine the pins the more I do believe the MOSFETs were soldered on. There is also a means to locate them after all. I should have remembered this during my disassembly, but there's a plastic bracket on top of the body pins but below the MOSFETs that has little notches to position them. As long as the new MOSFETs are the same dimensions this should aid in reassembly. I plan to try to desolder the main board to get access from underneath in the coming days/weeks. If that's successful then I'll purchase the new MOSFETs and attempt to resurrect this.
Perhaps you can modify the heat sink by tacking on long enough threads to exit the plastic lid. Then tighten it down externally after the lid is put back on. That way you don’t have to tighten from the side blocked by the green board. Obviously seal it when finished.
My 2006 S2000 has no power steering now. At first I’d lose power steering at low speeds. Turning the car off and restarting it reset the power steering. Not anymore. EPS DTC is 32-01 (Problem with main current sensor offset). Service Manual recommended checking the electrical connections.
I checked and cleaned the three EPS module connectors, and the connectors to the steering rack and torque sensor. No visible corrosion. Next, I tried replacing the EPS module. Since Honda no longer stocks this part, I got one off eBay. I installed the used module and reset the EPS. I still get the same DTC 32-01 code.
I measured a motor resistance of 0.3-0.4 ohms. That seems about right. After I start the car, the EPS light does not come on until I turn the steering wheel. I’m wondering if it’s the torque sensor. I checked the resistance on the three sensor pins for a short or open circuit. Got ~14 ohms measured between the two outside pins and the center pin. Measured ~28 ohms between the left and right pins. Any thoughts?
