Scanner Won't Connect

caladash · Apr 24, 2012

Got a late 99 truck that I can't get my scanner to connect to. All other vehicles work so the scanner is good. It's a snap on scanner. All fuses and such check good. Truck runs and drives great. Also the parking lights won't shut off after being turned on. Have to disconnect the batteries to get them to turn off. Not sure if it's related. Ideas?

caladash · Apr 24, 2012

Ideas?

02BigD · Apr 24, 2012

Smells like...ground issue?

TARM · Apr 24, 2012

I second a ground issue. Check your OHM on the ground pin out on the obdII connector as well as the power pin of course.

JLDickmon · Apr 25, 2012

02BigD said:
Smells like...ground issue?

smells like it to me as well

Gary · May 4, 2012

Check your OBD II port and see if you have 1 pin with battery voltage, I'm not sure which pin it is rite now, you could compare it to another vehicle's OBD II port. Your light issue sounds like a GEM module problem.

JLDickmon · May 5, 2012

you did check the port for the 4., 5., and 12v ref signals, right?

caladash · May 6, 2012

Update: finally got the scanner to connect. All pins checked good with the key off and on. Having a good pin out I hooked the scanner back up and wiggled the connector while it tried to connect. Of course it worked! I ended up having to put a lot of pressure upwards to maintain a good connection. Truck ended up having a good bill of health! As for the lights....the only way to turn them off is to pull the trailer parking lights fuse under the hood.