No response from ALDL

oldsalt · 08-01-2005, 05:04 PM

I have a 90 Corvette with ABS. Currently I have a 'Service ABS' indicator lit. Per the manual I put pin 'H' of the ALDL to ground to try and determine fault, but there is no code flashed, not even 12. Any suggestions where the problem lies? And yes, the ignition was 'ON'.

Blower91 · 08-01-2005, 05:59 PM

Try retrieving the codes through the CCM instead. When you ground pin H the EBCM only should flash its trouble codes. Code 12 is sent by ECM (or was is perhaps CCM, don't have my books here...) so it wont show up when you grund pin H. Pull the codes through the CCM and code 12 and the others should show up.

Ground pin G (G to A) and turn the ignition on. Then the CCM will enter diagnostic mode. It displays fault codes (in speedometer) for the CCM (module1), ECM (module4) and the EBCM (module9). End of list is indicated by "---".

Best of luck!

oldsalt · 08-01-2005, 07:55 PM

Thanks for the tip. I'll give it a try.