C146C

BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: VEHICLE STABILITY CONTROL SYSTEM: C146C: Open in ABS Motor Relay Circuit
C146C - Open in ABS Motor Relay Circuit

DESCRIPTION

The ABS motor relay supplies power to the pump motor. While the ABS is activated, the skid control ECU turns the ABS motor relay on to operate the pump motor.

If the voltage supplied to the ABS motor relay (+BM) is too low due to low voltage from the battery or alternator, the DTC may be stored.





WIRING DIAGRAM





INSPECTION PROCEDURE

HINT
When C1241 and/or C1417 is output together with C146C, inspect and repair the trouble areas indicated by C1241 and/or C1417 first C1241, and/or C1417).

PROCEDURE

1. PERFORM ACTIVE TEST USING TECHSTREAM (ABS MOTOR RELAY)

(a) Connect the Techstream to the DLC3.

(b) Start the engine.

(c) Select the Active Test using the Techstream Data List / Active Test.

ABS/VSC/TRAC





(d) Check the operating sound of the pump motor when operating it using the Techstream.

Result:





B -- CHECK HARNESS AND CONNECTOR (+BM TERMINAL)
A -- Continue to next step.

2. RECONFIRM DTC

HINT
This DTC is stored when a problem is identified in the brake actuator assembly.

The ABS motor relay is in the brake actuator assembly.

Therefore, motor relay inspection and motor relay unit inspection cannot be performed. Be sure to check if the DTC is output again before replacing the brake actuator assembly.

(a) Turn the ignition switch off.

(b) Clear the DTCs Reading and Clearing Diagnostic Trouble Codes.

(c) Turn the ignition switch off.

(d) Start the engine.

(e) Drive the vehicle at a speed of 40 km/h (25 mph) or more for 30 seconds or more.

(f) Check if the same DTC is output Reading and Clearing Diagnostic Trouble Codes.

Result:





HINT
* If a speed signal of 40 km/h (25 mph) or more is received by the skid control ECU with the ignition switch ON, the skid control ECU performs self diagnosis of the motor circuit.
* If the normal system code is output (No DTCs are output), slightly jiggle the connectors, wire harness, and fuses of the brake actuator assembly.
* If any DTCs are output while jiggling a connector or wire harness of the skid control ECU (brake actuator assembly), inspect and repair the connector or wire harness.
* If no DTCs were output when reconfirming DTCs, checking for intermittent problems is necessary because it is suspected that the original DTCs were stored due to the poor connection of a connector terminal.

B -- REPLACE BRAKE ACTUATOR ASSEMBLY Removal

A -- CHECK FOR INTERMITTENT PROBLEMS How To Proceed With Troubleshooting

3. CHECK HARNESS AND CONNECTOR (+BM TERMINAL)

(a) Check that the ABS NO. 1 (50 A) fuse is normal.





HINT
If the result is not as specified, replace the ABS NO. 1 fuse (fusible link block assembly).

(b) Make sure that there is no looseness at the locking part and the connecting part of the connector.

(c) Disconnect the skid control ECU connector.

(d) Measure the voltage according to the value(s) in the table below.

Standard Voltage:





Text in Illustration





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (+BM CIRCUIT)
OK -- Continue to next step.

4. CHECK HARNESS AND CONNECTOR (GND2 TERMINAL)

(a) Measure the resistance according to the value(s) in the table below.





Standard Resistance:





Text in Illustration





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (GND2 CIRCUIT)

OK -- REPLACE BRAKE ACTUATOR ASSEMBLY Removal