Short to B+ in ABS Motor Relay Circuit - Vehicle Stability Control System (w/ VDIM)

BRAKE CONTROL: VEHICLE STABILITY CONTROL SYSTEM (w/ VDIM): C0273/13: Open in ABS Motor Relay Circuit

DTC C0273/13 - Open in ABS Motor Relay Circuit

DTC C0274/14 - Short to B+ in ABS Motor Relay Circuit

DTC C1361/91 - Short Circuit in ABS Motor Fail Safe Relay Circuit

DESCRIPTION

If a DTC of the motor line is stored, the ABS MOTOR1 (fail safe) relay cuts off the power supply to the ABS MOTOR2 relay and performs fail safe.
While any of the ABS, TRAC, VSC, or BA is operating, the skid control ECU (housed in the actuator assembly) turns the ABS MOTOR2 relay on and activates the pump motor in the brake actuator.
This code may be stored if the motor relay (+BM) voltage becomes lower than the DTC detecting condition due to insufficient output from the battery or alternator.






WIRING DIAGRAM





INSPECTION PROCEDURE
NOTE: When replacing the skid control ECU, perform zero point calibration and store system information Vehicle Stability Control System (W/ VDIM).

PROCEDURE

1. INSPECT ABS1 FUSE





(a) Remove the ABS1 fuse from engine room No. 1 R/B.
(b) Measure the resistance according to the value(s) in the table below.
Standard resistance:






NG -- REPLACE ABS1 FUSE
OK -- Continue to next step.
2. INSPECT ABS MOTOR2 RELAY





(a) Install the ABS1 fuse.
(b) Remove the ABS MOTOR2 relay.
(c) Measure the resistance according to the value(s) in the table below.
Standard resistance:






NG -- REPLACE ABS MOTOR2 RELAY
OK -- Continue to next step.
3. INSPECT ABS MOTOR1 (FAIL SAFE) RELAY





(a) Remove the ABS MOTOR1 (fail safe) relay.
(b) Measure the resistance according to the value(s) in the table below.
Standard resistance:






NG -- REPLACE ABS MOTOR1 (FAIL SAFE) RELAY
OK -- Continue to next step.
4. INSPECT ENGINE ROOM NO. 3 RELAY BLOCK (POWER SOURCE TERMINAL)





(a) Measure the voltage according to the value(s) in the table below.
Standard voltage:






NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (POWER SOURCE CIRCUIT)
OK -- Continue to next step.
5. INSPECT ENGINE ROOM NO. 3 RELAY BLOCK





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






NG -- REPAIR OR REPLACE ENGINE ROOM NO. 3 RELAY BLOCK
OK -- Continue to next step.
6. INSPECT BRAKE ACTUATOR ASSEMBLY





(a) Disconnect the brake actuator connector.
(b) Measure the resistance according to the value(s) in the table below.
Standard resistance:






NG -- REPLACE BRAKE ACTUATOR ASSEMBLY
OK -- Continue to next step.
7. CHECK HARNESS AND CONNECTOR (BRAKE ACTUATOR ASSEMBLY - ENGINE ROOM NO. 3 RELAY BLOCK)





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






NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
8. CHECK HARNESS AND CONNECTOR (SKID CONTROL ECU - BRAKE ACTUATOR ASSEMBLY)





(a) Disconnect the skid control ECU connector.
(b) Measure the resistance according to the value(s) in the table below.
Standard resistance:






NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
9. CHECK HARNESS AND CONNECTOR (SKID CONTROL ECU - ENGINE ROOM NO. 3 RELAY BLOCK)





(a) Disconnect the skid control ECU connector.
(b) Measure the resistance according to the value(s) in the table below.
Standard resistance:






NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
10. RECONFIRM DTC
(a) Clear the DTC Vehicle Stability Control System (w/ VDIM).
(b) Start the engine.
(c) Drive the vehicle at the speed of 4 mph (6 km/h) or more.
(d) Check if the same DTC is recorded Vehicle Stability Control System (w/ VDIM).


HINT: Reinstall the relays, connectors, etc. and restore the vehicle to its prior condition before rechecking for DTCs.

Result:






HINT:
- If a speed signal of 4 mph (6 km/h) or more is input to the skid control ECU, with the engine switch on (IG) and the stop light switch off, the ECU performs self diagnosis of the motor and solenoid circuits.
- If the normal system code is output (the trouble code is not output), slightly jiggle the connectors, wire harness, and fuses of the skid control ECU and brake actuator assembly. Make sure that no DTCs are output.
- If any DTCs are output while jiggling a connector or wire harness of the skid control ECU and brake actuator assembly, inspect and repair the connector or wire harness.

B -- REPLACE SKID CONTROL ECU
A -- USE SIMULATION METHOD TO CHECK