94 Corvette LT1 trouble codes
Thread Starter
Melting Slicks
Joined: Feb 2005
Posts: 3,467
Likes: 43
From: Auburn MA
94 Corvette LT1 trouble codes
I am racking my brain trying to find out what these codes mean. I am getting a "Service ASR" light so I decided to pull the codes and this is what I got.
Module 1= C12
Module 4= H18
Module 9= H62, H64.
I could clear the H18 (Module 4) and the H62 (Module 9) but I can not clear the H64 or the C12. What do all these codes mean?
Module 1= C12
Module 4= H18
Module 9= H62, H64.
I could clear the H18 (Module 4) and the H62 (Module 9) but I can not clear the H64 or the C12. What do all these codes mean?
Last edited by Impala Balko; May 6, 2018 at 11:11 AM.
Zen Vet Master Level VII
Joined: Mar 2016
Posts: 5,218
Likes: 1,174
From: Southlake, TX
Try this:
And this:
https://tech.corvettecentral.com/201...trouble-codes/
The H is a "history code" so if you can't clear it don't fret. The C12 means that your computer has good continuity and comunication. It also begins and ends your sequence. You won't be able to erase this; this is a "good" code
And this:
https://tech.corvettecentral.com/201...trouble-codes/
The H is a "history code" so if you can't clear it don't fret. The C12 means that your computer has good continuity and comunication. It also begins and ends your sequence. You won't be able to erase this; this is a "good" code
Le Mans Master
Joined: Jan 2006
Posts: 5,621
Likes: 206
From: Orlando FL
C12 in module 1 means there are no codes in that module and all is OK and communicating.
There is no module 2, it is module 4 for the PCM
Code H18 is an fuel injector fault in the ground return circuit. It could be anything from a bad injector or bad connection at the injector or PCM connector.
A Tech 1 or Tech 2 has a test called injector balance test. It will tell you what injector is causing the code.
How are you clearing the codes? Are you using the on board diagnostics using the 9.7 to clear.
Code H64 is a throttle position signal problem as fed back to the EBTCM and interface module. There is no one quick answer if this is a real code. There is a whole lot going on here with several modules involved in regard to proper ASR operation.
There is no module 2, it is module 4 for the PCM
Code H18 is an fuel injector fault in the ground return circuit. It could be anything from a bad injector or bad connection at the injector or PCM connector.
A Tech 1 or Tech 2 has a test called injector balance test. It will tell you what injector is causing the code.
How are you clearing the codes? Are you using the on board diagnostics using the 9.7 to clear.
Code H64 is a throttle position signal problem as fed back to the EBTCM and interface module. There is no one quick answer if this is a real code. There is a whole lot going on here with several modules involved in regard to proper ASR operation.
Thread Starter
Melting Slicks
Joined: Feb 2005
Posts: 3,467
Likes: 43
From: Auburn MA
C12 in module 1 means there are no codes in that module and all is OK and communicating.
There is no module 2, it is module 4 for the PCM
Code H18 is an fuel injector fault in the ground return circuit. It could be anything from a bad injector or bad connection at the injector or PCM connector.
A Tech 1 or Tech 2 has a test called injector balance test. It will tell you what injector is causing the code.
How are you clearing the codes? Are you using the on board diagnostics using the 9.7 to clear.
Code H64 is a throttle position signal problem as fed back to the EBTCM and interface module. There is no one quick answer if this is a real code. There is a whole lot going on here with several modules involved in regard to proper ASR operation.
There is no module 2, it is module 4 for the PCM
Code H18 is an fuel injector fault in the ground return circuit. It could be anything from a bad injector or bad connection at the injector or PCM connector.
A Tech 1 or Tech 2 has a test called injector balance test. It will tell you what injector is causing the code.
How are you clearing the codes? Are you using the on board diagnostics using the 9.7 to clear.
Code H64 is a throttle position signal problem as fed back to the EBTCM and interface module. There is no one quick answer if this is a real code. There is a whole lot going on here with several modules involved in regard to proper ASR operation.
Thread Starter
Melting Slicks
Joined: Feb 2005
Posts: 3,467
Likes: 43
From: Auburn MA
the off thing is the car runs and idles and runs all the way through the rev range fine with the exception of throwing the "Service ASR" light... and some time it stays on and sometimes it doesn't come on at all
Thread Starter
Melting Slicks
Joined: Feb 2005
Posts: 3,467
Likes: 43
From: Auburn MA
After hooking a multi-meter up to the TPS I noticed at idle it was around .4-.45v and at WOT it was only at 4v so I replaced the TPS sensor. I still can not clear out that code and when the car is in Accessory mode the Service ASR light is still on. Is this something that stays on until the car is started and if not do I have to drive it around to clear the code?
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Thread Starter
Melting Slicks
Joined: Feb 2005
Posts: 3,467
Likes: 43
From: Auburn MA
I still have the service ASR light after replacing the TPS... I don't know what else to do. Only othe lt1 guess is wiring... anyone have an idea on how to trouble shoot the wiring
