2003 Chevrolet Suburban

I have an OTC scan tool and when I hook it up to the trouble code socket it can not communicate with the on board computer.

The local DEQ has the same problem. All fuses seem to be fine.

What could cause this problem?
David Walker
April 12, 2007.

May be a problem the the Data Link Connector, the computer itself or wiring between them. Get a good look at the connector for corrosion or abnormalities.

Thanks. I will check. The socket is an easy inspection but how do I tell if the other parts are defective. Vehicle does not seem to have any drivability problems. Just won't talk to the tool.

Is there a break out of the data port on the scoket?

I assume two of the ports sent Bat votage to the reader.

David Walker
Apr 13, 2007.

Motor size?

Why are you needing the codes? CEL on?

Assuming so,
The performance may appear fine for a few reasons. One it may have to do with the evaporative system that essentially has no affect on performance. Second if there is something such an input to the pcm like a cps that is out of spec, the computer will ignore it and use a default value.

Access is needed to pass the yearly inspection and there are no trouble codes lit.

So it is a cosmetic issue at this point.

This vehicle has had numerous issues with the driverrs electric seat. The hot wire to the heated seat was grounding out when someone was in the seat.

Now the five way switch seams to be grounding out as well.

My scan tool will do the same code scan as the State but we both have to be able to communicate with the cpm/cpu.

So I don't know how to determine if the OBD is not talking to the plug or if the problem is internal.

David Walker
Apr 14, 2007.