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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Automatic

A/C System Inspection at ECM

Voltage Check
ECM and its circuits can be checked at ECM wiring couplers by measuring voltage.

CAUTION: ECM cannot be checked by itself. It is strictly prohibited to connect voltmeter or ohmmeter to ECM with couplers disconnected from ECM.




1. Remove ECM from vehicle by.
2. Connect ECM couplers (1) to ECM (2).
3. Check voltage at each terminal of couplers connected.

NOTE: As each terminal voltage is affected by the battery voltage, confirm that the battery voltage is 11 V or more when ignition switch is ON position.










ECM Voltage Values Table for Relation of A/C Control