scanner will not connect to PCM

Maniak87 · May 11, 2011

so i was trying to pull codes from my 94 cobra today. the scan tool will not establish connection to the PCM. my check engine light is not coming on but i want to see the codes that are being stored.

my radiator fan is running all the time so i am trying to diagnose why. i am also having a weird voltage issue. i now have a new battery and alternator but somtimes when im driving, it will stumble over itself and almost die, check engine will flash quickly then turn off but then the car continues to run like nothing happend. it did it once today on a 35min drive but never did it again an hour later.

would a bad ccrm or pcm cause a scan tool not to read? what would cause this?

94svtturbo · May 11, 2011

What plug were you hooking up to? If you are hooking up to the one under the dash it will not work. There is a diagnostic port under the hood between your passenger strut tower and firewall. The one under the dash is in prep for 96 and newer cars when they switched over to OBD 2. Our cars still run on an OBD 1 system

Maniak87 · May 11, 2011

94svtturbo said:
What plug were you hooking up to? If you are hooking up to the one under the dash it will not work. There is a diagnostic port under the hood between your passenger strut tower and firewall. The one under the dash is in prep for 96 and newer cars when they switched over to OBD 2. Our cars still run on an OBD 1 system

the one under the hood....