My car runs fine until it warms up and then it barely can pulls it's own weight. I keep getting DTC 42 on my scanner. I thought it was my ignition module and so I had mine tested and they said it tested bad. Not real sure if the guy new what he was doing. So I bought a new one and brought it home and the same thing happened, DTC 42 on my scanner. Any thoughts on the direction I should take. I have done the cooling mod and the mount bolts are tight and also the grounds are secure and tight. No other codes are present at this time. I think it might be in the wiring but not real sure. I am getting my repair manual out and see if I can find voltage numbers for the wiring at the ignition module. I have been stumped for sometime now and finally resorting to asking the forum. Thanks for any advice, Zane.

 

Did you reset the codes to clear them and it came back? Pull the fuse for the computer for 30 seconds and try it again if not after running it for awhile.

 

I cleared the code with my scanner before starting it after I replaced the ignition module. I am gonna check voltage values and post what I find. Any other ideas, I am thinking it's in the wiring.

 

I had good voltage on the pink/black wire and the white/black wire at the ignition module with the switch on. I need to have someone turn the motor over for me to check the voltage on white wire. I will do that tomorrow. Anyone have any ideas on what my problem could be? It only does it after the car gets warm so something is breaking down from the heat. PCM maybe?

 

You can relocate it to a better location. Here some more info. https://www.camaroz28.com/forums/sho...&highlight=icmThere are tons of threads on this here. Did you use this when you replaced it? https://www.camaroz28.com/forums/sho...&highlight=icm

 

I am currently running the cooling mod on my ignition module and I used the dielectric grease when I installed it. The car runs fine until it gets hot then it runs like crap. The 160 degree thermostat and electric water pump never let the car get over 180 degrees anyways. So the temp really isn't that high compared to some other cars I've been in. Guys I need some help here.

 

The factory manual has a good logic diagram for diagnosing DTC 42. Causes are not limited to the IC Module. Shoebox may have the diagram online.

 

I checked the voltage coming from the PCM to the ICM and I got 2 volts, I know the manual says I'm supposed to have five volts. So where do I go from here? Replace computer? I did a continuity check on the white wire coming from the PCM to the ICM and the continuity was good. Any thoughts?

 

try a voltage drop test, continuity or an ohms test does not tell you much about the condition of a wire. do you have 5 volts at the pcm?

 

I didn't check the voltage coming directly out of the PCM just at the ICM. Will do that tonight. How do I do a voltage drop test?

 

ttt