Operation CHARM: Car repair manuals for everyone.
Manuals through 2025 now available!

Our trusted friends have launched a new website named LEMON, which has newer manuals. It also contains all the CHARM manuals.

LEMON is the spiritual successor to CHARM, I recommend you try it!

Link: lemon-manuals.la or lemon-manuals.org.ua

(Some people have issue connecting. LEMON is investigating. For now, use Firefox or change your DNS server)

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Speed Control Will Not Slow Down

Fig. 9 PCM 40-Way Connectors:






Check for diagnostic trouble codes. If code 34 or no code present, perform the following test:
1. Conduct the speed control switch test on the resume SET/COAST.
2. If it fails, replace switch.
3. If it passes use an ohmmeter to test continuity between pin 2 of SET/COAST switch connector and ground. Wiggle wires while performing test. If no continuity repair circuit.
4. If continuity, test continuity between pin 1 of SET/COAST switch connector and pin 41 of the PCM 40 way connector. Wiggle wires while performing test. If no continuity repair circuit.
5. If continuity, disconnect the servo connector. Test continuity from pin 2 of connector and ground to test for intermittent short. Wiggle wires while performing test. If continuity repair circuit.
6. If no continuity, conduct the servo vacuum test. If it fails, replace servo.
7. If it passes, replace the PCM