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DTC P1689 need a bit help

SDGTP99

SDGTP99

New member
I thought I had this code taken care of. I cleaned the PCM & ABS connections on the wiring harness and the abs light went off. Then I cleared the p1689 code. Car ran great. Day later the code came back & it won't clear.
 


That's exactly what I said when it first popped up. It isn't in the Chilton manual so I had to Google it to find out what it was. Its a problem with PCM or PCM connection, ABS & the wiring between them. I thought the code was set by the loose connection at the ABS plug(Which was very dirty). I also cleaned up the connection plugs to the PCM. But the code came right back. However the ABS light did turn off after all the cleaning. I have checked out the code out at GearChatter & Ill admit I was confused on how tontroubleshoot the code. =\
 
Is it a class 2 data error?

Supossedly those lines have connectors in them that corrode and fail.

Have you traced the entire circuit?
 


Hmm, I don't have cruise control. I'm sure that's part of the DTC P1689. I checked the cruise control fuse and the wiring to cruise control & it all checks out. I haven't been able to find any bad wiring at all so far. Tommoro I'm going to try a different PCM and see if the code dissapears. After that idk what to do.
 


The problem was a broken fasteners where the wiring harness connects to the EBCM. I switched out the broken part from my old harness and problem solved. And no I don't have a bulb out in my third brake light. Stoll no cruise control.
 


I've been driving my car about 2 weeks now. Today I got a DTC P1585 which is cruise control inhibit. No wonder I don't have cruise control.
 
GM Service Manual:
DTC P1558 set indicates that an improper voltage level has been detected on the signal circuit which controls the cruise control inhibit circuit.
• The history DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction.
Step 1:
Turn OFF the ignition.
Disconnect the PCM harness connector.
Turn ON the ignition, with the engine OFF.
Using a DMM connected to a good ground, measure the voltage of the cruise control inhibit signal circuit. (B+... = "90V DC"?)
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  1. If 90VDC, go to Step 2. If not, go to Step 3.

    Step 2:
    Turn OFF the ignition.
    Disconnect the cruise control module.
    Turn ON the ignition, with the engine OFF.
    Probe the cruise control inhibit signal circuit with a test lamp that is connected to a good ground.

    If it doesn't light up, inspect for poor connections at the harness connector of the PCM. If it lights up, inspect for poor connections at the harness connector of the cruise control module.

    Step 3.
    Test the cruise control inhibit signal circuit for a open, high resistance or short to ground.
    If the condition is there, inspect for poor connections at the harness connector of the cruise control module. Else, clear the DTC.
 
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