Codes flash from OBD 1 6-1 and 1-3. Any help understanding where to look is appreciated.

 

https://repairpal.com/gm-obd-i-code-chart

 

Thank you mountainmanJoe, I have the physical manuals that specify what the codes mean. The beast has been scanned with a snap-on with keys also. Just not sure where to look for system clog, failed relay, shorted ground, etc. Sorry, should've specified a bit more clearly. Also forgot to specify, this is for ABS system.

 

Code 13 Oxygen sensor circuit open or no activity

Are the wires to the O2 sensor broken off?


Code 61 A/C system performance

Does it need a recharge?

 

Those are for engine trouble codes. (Yes it needs a new compressor also). Engine throws no codes at all. Again, these codes are ABS faults. Should be the 4WAL system in 2WD mode.

 

OK so if your manuals tell you what the codes mean then ....

what do they mean?? I feel like I'm pulling teeth.

 

Where do I go with this info? I'm as confused as you are.

 

To me it sounds like code 13 means that you had your foot on the brake pedal when you read the OBD codes, and everything is working normally. If not then you go to the diagnostic chart mentioned.

As for the isolation valve one, the instructions sounds fairly straightforward. Did you follow them?

 

Should've done this before. Purchase was made from CL, sat forever, no previous owner history. Fleet PM was performed (included new brake lines and flush.) The open circuit refers to the upper brake lamp that needs some attention, I think. The 61 may have been from dirty system. Performed a system clear (didn't know the system holds onto codes like that) and will road test on the way to work. That you again for the assist on this head scratcher.

 

Ok, after clearing the codes and driving to work, final current state is no dash lights until 10mph. ABS only illuminates above. Immediately turns back off as soon as under 10 again. Stores two codes still. 61 became 81. 13 remains the same. Have been present during a SNAP-ON scan, that uncovered no signal to passenger front WSS. DISCOED part. (#15999174 also used in other full sized trucks until mid 90's.) Will be picking the bone yard for one that works. Also the upper brake lamp has not functioned since purchase, another unicorn part. So no CC that's found anyways.


Have not tested ABS function yet due to a very eventful day.