Test J: DTC C1840 - Air Suspension Service Switch Circuit Failure

Pinpoint Test J: DTC C1840 - Air Suspension Service Switch Circuit Failure
Normal Operation
The air suspension service switch is a normally-closed switch that is used to turn the vehicle dynamic suspension system ON and OFF. The vehicle dynamic module (VDM) sends voltage along circuit 429 (VT/LG) into the switch and looks for that voltage to return along circuit 418 (DG/YE). If the VDM does not receive voltage along circuit 418 (DG/YE) it will deactivate the vehicle dynamic suspension system.

Possible Causes
^ Circuit open
^ Circuit shorted
^ Air suspension service switch
^ VDM

PINPOINT TEST J: DTC C1840 - AIR SUSPENSION SERVICE SWITCH CIRCUIT FAILURE

J1-J5:

CAUTION: The Flex Probe Kit must be used for all test connections. Use of standard multimeter probes may damage wiring terminals.