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

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A/C Signal: Testing and Inspection




1. Start the engine.
2. Turn the A/C switch and fan switch to ON.
3. Verify that the A/C compressor magnetic clutch actuates.
4. If it does not actuate, go to troubleshooting of the A/C.
5. Fully open the throttle valve and verify that the A/C compressor magnetic clutch does not actuate for 2 - 5 seconds.
6. If it actuates, check the following.




7. Connect the SSTs (NGS tester) to the data link connector.
8. Turn the A/C switch to OFF.
9. Turn the ignition switch to ON.
10. Select "SIMULATION TEST' and press TRIGGER.
11. Select "IG ON TEST" and press TRIGGER.
12. Select "A/C RLY" and press TRIGGER.
13. Press START.
14. Turn the A/C relay from OFF to ON and check if the operation
sound of the relay is heard.
15. If the operation sound is heard, check the PCM terminal 3F voltage.
16. If the operation sound is not heard, check the A/C relay.