Getting the CCM diagnostic to work
Thread Starter
Zen Vet Master Level VII
Joined: Mar 2016
Posts: 5,218
Likes: 1,174
From: Southlake, TX
Getting the CCM diagnostic to work
Hey all, can I get a couple of hints to make the CCM diagnostic run on my '91 ZR1 please?
I have a hand held unit (a left over from my '82 with the OBD1 connection) and when plug it in, I get the full on ECM treatment with the flashing codes on the DIC. Currently I'm getting repeating 1-2 so I'm good.
I have tried to jump the grounds from the A to G on the terminal with a paper clip and with no luck. I don't have anything wrong with the car, I just want to learn how the CCM diagnostic operates. The CCM read out looks very cool and has a lot more information.
So, am I just doing it wrong on the paper clip jump on the terminal? Does the car read both ECM and CCM depending on the ground or does it read only one or the other?
Thanks!
I have a hand held unit (a left over from my '82 with the OBD1 connection) and when plug it in, I get the full on ECM treatment with the flashing codes on the DIC. Currently I'm getting repeating 1-2 so I'm good.
I have tried to jump the grounds from the A to G on the terminal with a paper clip and with no luck. I don't have anything wrong with the car, I just want to learn how the CCM diagnostic operates. The CCM read out looks very cool and has a lot more information.
So, am I just doing it wrong on the paper clip jump on the terminal? Does the car read both ECM and CCM depending on the ground or does it read only one or the other?
Thanks!
Safety Car
Joined: Jun 2010
Posts: 4,564
Likes: 1,676
That is incorrect. You go into module 4 and it gives you the ECM trouble codes for L98LT1 or LT5. The service manual even gives you a list of codes for whatever ECM is present in the car.
Safety Car
Joined: Jun 2010
Posts: 4,564
Likes: 1,676
And to specify, year of manual, page and color of the manual (red or white)?
*Update* it appears you are working out of a 93 FSM. I see the statement you mention about the LT5 on 8D-9. Which is odd, as the 90, 91, 92, includes LT5 ECM diagnostics in the CCM module 4. Then the 94 and 95 books make no mention of the LT5 ECM being excluded specifically like the 93 book.
For the OP with his being a 91, he will be able to access it through the CCM.
Last edited by ChumpVette; Jan 18, 2017 at 01:34 AM.
Team Owner
Joined: Sep 2003
Posts: 25,394
Likes: 2,741
What year(s)?
And to specify, year of manual, page and color of the manual (red or white)?
*Update* it appears you are working out of a 93 FSM. I see the statement you mention about the LT5 on 8D-9. Which is odd, as the 90, 91, 92, includes LT5 ECM diagnostics in the CCM module 4. Then the 94 and 95 books make no mention of the LT5 ECM being excluded specifically like the 93 book.
For the OP with his being a 91, he will be able to access it through the CCM.
And to specify, year of manual, page and color of the manual (red or white)?
*Update* it appears you are working out of a 93 FSM. I see the statement you mention about the LT5 on 8D-9. Which is odd, as the 90, 91, 92, includes LT5 ECM diagnostics in the CCM module 4. Then the 94 and 95 books make no mention of the LT5 ECM being excluded specifically like the 93 book.
For the OP with his being a 91, he will be able to access it through the CCM.
Here's the excerpt from the FSM that IHBD has mentioned. It does state that so if you've a '93 ZR-1/LT5 how about giving it a try.
Last edited by WVZR-1; Jan 18, 2017 at 08:15 AM.
Thread Starter
Zen Vet Master Level VII
Joined: Mar 2016
Posts: 5,218
Likes: 1,174
From: Southlake, TX
*Update* it appears you are working out of a 93 FSM. I see the statement you mention about the LT5 on 8D-9. Which is odd, as the 90, 91, 92, includes LT5 ECM diagnostics in the CCM module 4. Then the 94 and 95 books make no mention of the LT5 ECM being excluded specifically like the 93 book.
For the OP with his being a 91, he will be able to access it through the CCM.
For the OP with his being a 91, he will be able to access it through the CCM.
After my brain fart cleared, I was able to the the CCM codes and diagnostics to work. It was my error as I was not "pushing" my wire far enough in the terminal-- I was simply being too ginger with it.
Once jumped the CCM codes came on and work exactly as outlined the the FSM. Mercifully I saw only "C12" and "---" for all modules and I cleared all the .7s for good measure.
I do have a "history" marker of 1-3 for the INFL REST, but that is a different story
