DTC 74

DTC 74 - VEHICLE HEIGHT CONTROL POWER SOURCE CIRCUIT

CIRCUIT DESCRIPTION





When the ignition switch is turned on, battery voltage is applied to terminal IG of the suspension ECU. When this happens, the No.2 height control relay control circuit in the ECU sends signals to terminal MRLY and switches the No.2 height control relay on. This causes current to flow to the coil and thus the contacts in the No.2 height control relay close. This in turn causes battery voltage to be supplied to terminal IGB. Terminal IGB is the power supply for driving the height control valve and terminal IG is used as the power supply for the suspension control indicator. Furthermore, the ECU detects the ignition switch on or off condition at terminal IG. Even when the ignition switch is turned off, the ECU continues to send signals to No.2 height control relay from terminal MRLY to keep it on for a set period of time to perform Ignition Switch Off Control.





DIAGNOSTIC CHART





WIRING DIAGRAM

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INSPECTION PROCEDURE