ECM DTC's for Cluster Display '93 MY

[WVZR-1]

The '93 FSM states on 8D-9 that ECM DTC's isn't available for the LT5 using the CCM procedure. That seems ODD and it might be interesting if someone with a '93 actually confirms a YES/NO! Maybe 1st year EGR the LT5 cluster wouldn't communicate with the CCM/ECM using the DIC. I've no idea but it certainly is interesting.

Here's an excerpt from the '93 FSM

'93 8D-9.jpg

[-=Jeff=-]

I think it has to do with the newer ECM design for the 93 LT1 maybe? I know the 92 and 93 ECM for LT1 are different part numbers and not sure if they can interchange

[billschroeder5842]

Thanks WVZR-1 for the question. I posted the original on CF as I thought it was a C4 thing and not a LT5 issue but apparently it is.

I can get my '91s ECM to display the flashes but can't get the CCM to do diddley.

Thanks!

[WVZR-1]

Originally Posted by billschroeder5842

Thanks WVZR-1 for the question. I posted the original on CF as I thought it was a C4 thing and not a LT5 issue but apparently it is.

I can get my '91s ECM to display the flashes but can't get the CCM to do diddley.

Thanks!

It's not an LT5 issue except as the FSM "hints" maybe for the '93. Is the FSM in error for the '93? Maybe - that's why I presented the question here. I assumed someone with a '93 would confirm YES/NO with an attempt or from experience can definitely confirm the FSM statement "fact/fiction".

If you can't get the CCM diagnostics to work then something is "busted" or you ain't doing it right. For your '91 you do all of the CCM diagnostics and the first note in the procedures is mention that CCM diagnostics won't function if the AC FUSE is blown I believe. For your '91 you need to go directly to the FSM and sort your issues. If a CCM was replaced and not correctly programmed might it NOT function as thought? I've no idea. Have the CCM scanned with a Tech1 and confirm that the VIN appears. Is your VATS still active and not by-passed using a resistor? If VATS is active the CCM controls it so it could be assumed that it's either original or if replaced was properly programmed.

Originally Posted by -=Jeff=-

I think it has to do with the newer ECM design for the 93 LT1 maybe? I know the 92 and 93 ECM for LT1 are different part numbers and not sure if they can interchange

I'd think not. Components seem to be:

'92 - '93 LT1 ECM the same, '92 - '93 DIC ALL the same, '92 - '93 LT5 ECM the same, '92 - '93 CCM ALL the same

[WVZR-1]

No one with a '93 has had an opportunity to confirm the operation of diagnostics using the DIC and the CLUSTER LCD? I thought sure someone would try!!

[Marc Haibeck]

All '93 ZR-1's are like that. CCM display module 4.0 shows "Err". You need to blink the SES lamp to check for ECM error codes.

[WVZR-1]

Originally Posted by Marc Haibeck

All '93 ZR-1's are like that. CCM display module 4.0 shows "Err". You need to blink the SES lamp to check for ECM error codes.

Thank you Marc!!