DTC42 IC circuit troubleshooting

Reply Subscribe

Thread Tools

Search this Thread

Oct 3, 2021 | 01:09 PM

9T3VETTE

Thread Starter

Drifting

Joined: May 2007

Posts: 1,426

Likes: 165

From: Motor City

DTC42 IC circuit troubleshooting

Pulling out of the garage yesterday and the car randomly shut off and would not restart. Never has happened before. Pulled codes and had an H42.

Looking at the FSM troubleshooting and my ICM connector wiring color does not match the book? I’ve GOT to be missing something here??

Oct 3, 2021 | 01:29 PM

9T3VETTE

Thread Starter

Drifting

Joined: May 2007

Posts: 1,426

Likes: 165

From: Motor City

Well it likely doesn’t matter, i probed ecm pin a12 which is ignition control (white) and nobody is home. Looks to be a bad ecm (again!)

diagnostic page below for reference

Oct 3, 2021 | 01:42 PM

ajp01

Drifting

Joined: Jan 2021

Posts: 1,313

Likes: 384

From: Northern California

If it makes you feel any better your ICM connector wiring colors look right to me. A=pnk/blk, B=wht, C=blk, D=wht. The FSM sequence shown on the picture has weird sequencing of A,B,C,D, just because I think it's easier for them to show the layout of the circuits on the picture, but your connector does have the colors/layout indicated on the FSM chart.

Good luck with the ECM swap-out.

Oct 3, 2021 | 03:01 PM

9T3VETTE

Thread Starter

Drifting

Joined: May 2007

Posts: 1,426

Likes: 165

From: Motor City

^thats it! Never would have thought about them being out of order. Thanks!

Oct 3, 2021 | 09:18 PM

9T3VETTE

Thread Starter

Drifting

Joined: May 2007

Posts: 1,426

Likes: 165

From: Motor City

Went through the failure tree again and it’s looks like ICM is the issue, not the ECM.

what the consensus on best replacement brand?

is it best practice to replace the coil as well?

Reply Subscribe

Reply Share

First
Prev
1 / 1
Next
Last

Forum Jump