Diagnostic Procedure

DTC C1A77-11; C1A77-12 C1A77-49; MOTOR RELAY MALFUNCTION DIAGNOSTIC PROCEDURE

Step	Inspection		Action
1	INSPECT FUSE CONDITION Is the fuse (ABS/DSCM 50A) normal?	Yes	Go to the next step.
1	INSPECT FUSE CONDITION Is the fuse (ABS/DSCM 50A) normal?	No	If the fuse is blown: Refer to the wiring diagram and verify whether or not there is a common connector between fuse and DSC HU/CM terminal B. If there is a common connector: Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for a short to ground. Repair or replace the malfunctioning part. If there is no common connector: Repair or replace the wiring harness which has a short to ground. Replace the fuse. If the fuse is damaged: Replace the fuse. Go to Step 5.
2	VERIFY PUMP MOTOR OPERATION Using the M-MDS, perform the simulation inspection for pump motor. (See SIMULATION INSPECTION [DSC HU/CM] .) Does the pump motor operate?	Yes	Go to Step 5.
2		No	Go to the next step.
3	INSPECT MOTOR RELAY POWER SUPPLY CIRCUIT FOR OPEN OR SHORT TO GROUND CIRCUIT Switch the ignition OFF. Disconnect the DSC HU/CM connector. Switch the ignition ON (engine off). Measure the voltage between DSC HU/CM terminal B (wiring harness-side) and body ground. Is the voltage 10 V or more?	Yes	Go to the next Step.
3		No	Refer to the wiring diagram and verify whether or not there is a common connector between battery and DSC HU/CM terminal B. If there is a common connector: Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for an open or short circuit. Repair or replace the malfunctioning part. If there is no common connector: Repair or replace the wiring harness which has an open or short circuit. Go to Step 5.
4	INSPECT MOTOR RELAY GROUND CIRCUIT FOR OPEN CIRCUIT OR POOR GROUND Switch the ignition OFF. Disconnect the DSC HU/CM connector. Measure the resistance between DSC HU/CM terminal AL (wiring harness-side) and body ground. Is the resistance 0-1 ohm?	Yes	Go to the next step.
4		No	If the open circuit could be detected in the wiring harness: Refer to the wiring diagram and verify whether or not there is a common connector between DSC HU/CM terminal AL and body ground. If there is a common connector: Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for an open circuit. Repair or replace the malfunctioning part. If there is no common connector: Repair or replace the wiring harness which has an open circuit. Go to the next step. If the resistance is out of specification: Refer to the wiring diagram and verify whether or not there is a common connector between DSC HU/CM terminal AL and body ground. If there is a common connector: Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for a poor ground. Repair or replace the malfunctioning part. If there is no common connector: Repair or replace the wiring harness which has a poor ground. Go to the next step.
5	VERIFY DTC TROUBLESHOOTING COMPLETED Reconnect all disconnected connectors. Using the M-MDS, clear the DTC from the DSC HU/CM. (See CLEARING DTC [DSC HU/CM] .) Using the M-MDS, perform the DSC HU/CM DTC inspection. (See DTC INSPECTION [DSC HU/CM] .) Is the same DTC present?	Yes	Repeat the inspection from Step1. If the malfunction recurs, replace the DSC HU/CM, then go to the next step. (See DSC HU/CM REMOVAL/INSTALLATION .)
5		No	Go to the next step.
6	VERIFY NO DTC IS PRESENT Are any DTCs present?	Yes	Go to the applicable DTC inspection. (See DTC TABLE [DSC HU/CM] .)
6	VERIFY NO DTC IS PRESENT Are any DTCs present?	No	DTC troubleshooting completed.