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 Slows Down By Itself

Fig. 9 PCM 40-Way Connectors:






Test vehicle speed sensor. If sensor fails replace sensor, if it passes perform the following test:
1. Perform the speed control switch test on the SET/COAST switch, if it fails replace switch.
2. If the switch passes, conduct the vacuum supply test.
3. If it passes, conduct the servo vacuum test, if it fails replace servo.
4. If it passes, test continuity of pin 2 of harness connector to PCM pin 80 for intermittent open. Wiggle wires while performing this test. If continuity to pin 80, repair harness for open.
5. If no continuity, replace the PCM.