Help, how do I swap my 2002 Rodeo PCM with a replacement?

[PeterA]

Ok so how now do I trace where the legs of the mosfets go to. I know pin E1 on the plug is electronic spark timing coil driver A. Which is the middle leg of the left FET.

And pin E4 is coil driver B and matches to the right FET middle leg.

I think the FET's are ok. Not 100% sure though just watched some videos on how to test.


Ho do I trace the legs of the FET's back to those two 14 legged ic's.

[VX L67 Getrag]

Another way around it "maybe" is if anyone has mapped out data off memcal there could be a bit flag to disable theft.

[antus]

If you have a spare pcm change all of them in one hit. Probably the simplest option and a reasonable chance it'll work. What state are you in?

[PeterA]

I am in Qld antus. You mean change over all of them as in just those two FETs on the left hand side? or do you mean all the FET's on the heatsink? Or do you mean all the big chips + FETS?

[antus]

I mean the FETs which look like they're driving the outputs you are having trouble with.

[PeterA]

When mosfets fail apparently the fail pretty bad. I can not smell any smoke or the burnt electrical smell anywhere on the board. Do mosfets become intermittent and only work sometimes?

The reason I am asking is maybe the fet is good, but further back upstream some of the IC's might be faulty. So changing over the Fets may not do anything.

[antus]

I dont know. I know from my days with radios, generally the high power outputs fail more often than the drivers further upstream. But im not a hardware guru. I know enough to trouble shoot a digital circuit, but a fault like that in the analog side of a pcm would be more trial and error for me. The most common faults in general electronics is solder dry joints. In this case a tiny but visible crack can be seen in a ring around the component pin in the solder where it joins the board. Its continuity is intermittent depending on physical vibration and expansion due to temperature. A fault like that would cause what you describe with no explosions. Either the FET would loose its power source or signal source. If you swapped them it'd take care of any issue like that and any potential issue of the component being dead. Beyond trying that though, and getting the tool to link the replacement PCM, im out of suggestions.