Flashing codes

[edfiero1]

I'm not able to flash/display the SES codes when I ground the ALDL connector.

With the key on, engine off, the light is illuminated, but it doesn't flash when I ground A and B together

Is that indicative of any specific problem? Is there any work around for this? I was going to try to back probe A9 and A12 directly at the ECM and see if that would produce different results.

Appreciate any advice.
Thanks.

 

[salvageV6]

Page 6E3-A3-30 from the manual easy to get a free copy.

" A steady light suggests a short to ground in the light control circuit 419 A5 wire, or an open in diagnostic circuit 451 A9 wire. "

Disconnect the ECM connector and then turn the key on and it will check for a short in the wire circuit 419 A5.

If the light goes out theres no short.

Page has further tests so download a copy of the manual, 1987 version is what I have here.