Impala Balko

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?

billschroeder5842

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

pcolt94

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.

Impala Balko

I meant module 4... I am clearing them by going to 1.7, 4.7, and 9.7 and holding the ENG/MET button until “---“ is displayed. All the other stored codes made sense and have been resolved so now I need to figure out the TPS.... Does anyone have a wiring diagram maybe it could be as simple as something isn't plugged in somewhere down the line.... I can see the TPS is actually plugged however. How can you test this sensor to make sure it's working?

Impala Balko

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

1993C4LT1

So does it throw the Service ASR light when you go WOT? My car would do that to me as well. It was low on brake fluid.

Impala Balko

It would do it upon initial startup or after the car was running for a bit.

Impala Balko

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?

Impala Balko

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

94c4er

The TPS referenced with Code 64 refers to the Throttle Position Sensor Interface Module which is located on the passenger side under the coolant tank on the firewall.

Impala Balko

Anyone have a picture of this module and how do I test this thing

Impala Balko

That throttle position module was the fix... it is cured I am so glad it wasn't wiring related