Error Code 42, help me please...

[Changa]

Got code 42 today. The thing that happens is whilst driving or just whenever the car is running, it randomly drops about 300-500revs and then recovers, like its about to stall but doesnt, the enigne light flashes for about half a second but then its gone again. I swapped the DFI module out with a mates one and it still does the same thing with his, so it cant be that. I have tested the leads and coils with a multimetre and its all good, and I am pretty sure a plug wouldnt do it, as that isnt normally a symptom of a plug and mine are near new. Been searching and a few people said to check the wiring harness to the dfi module or whether I have a dud battery. So I have to look at the black/tan wire, not sure what I am looking for either. Any help would be great. I have a 1996 VS V6 auto commodore. This problem randomly occurs doesnt matter whether you rev the shit out of it or just let it idle. Can do it in any gear even park. Can happen 6 times on my way to work, or it might not happen at all.

[alex2_s]

Code 42 is electronic timing bypass circuit and relates to the DFI Ignition module (of course like with any other fault code, it COULD be the ECU playing up itself). It usually happens when the wiring connector to the right of the module is faulty (they get a short in one of hte little wire pin thingos) or the DFI module itself is playing up.

Sounds like the actual module in this case given it has an effect on the running of the engine. My light came on but there was no difference in driving as only that wire as i mentioned was faulty which would be only in use when the electronically-controlled timing was disregarded (bypass circuit) or so i believe.

Check the wiring is correctly plugged in (along with all ignition leads + coil packs correctly fastened to the module), if no luck, replace the DFI module...

[delcowizzid]

ide start by wiggling the dfi wiring at idle and see if you can make it happen

[Changa]

Yeah my mate suggested wiggling it as well. It is near impossible the DFI module is faulty as I have swapped it out and put a mates one in from a lexcen which is prefectly fine in his car and mine still had the same problem. Anyways I shall try wiggling the wiring harness around. If that is the problem, how do I fix it? Take it to an auto electrician and tell em to put a new harness in?

[ephect]

did the pins in the plug look corroded or damaged in any way?

[Changa]

Nah I could see no obvious wear and tear they looked in top condition to me, just a bit of dirt around the outside of the harness but that is expected. So Im not sure as to what it really is yet

[greenacc]

just for good measure check aright along the engine harness for any damage, dirty earths, kinks, short circuits... any of these can throw a code

[Changa]

Yeah I checked the earths, but to be honest all the other stuff you said I would have no idea if it looked fine or was screwed. I found three earths, one near the battery, one on the front left hand side about middle of the engine (if standing facing the engine from the front) and another at the back right hand middle part. I took these off cleaned em with a wire brush and then tightened them up as much as possible. Where are the other earths?