Short to B+ in ABS Motor Relay Circuit - Vehicle Stability Control System

BRAKE CONTROL: VEHICLE STABILITY CONTROL SYSTEM: 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 VSC No. 2 relay cuts off the power supply to the VSC No. 1 relay and performs fail-safe.
While any of the ABS, TRAC, VSC, or BA is operating, the skid control ECU (housed in the ABS & TRACTION actuator assembly) turns the VSC No. 2 relay on and activates the pump motor in the ABS & TRACTION 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 ABS & TRACTION actuator assembly, perform zero point calibration Programming and Relearning.

PROCEDURE

1. INSPECT FUSE (ABS/VSC NO. 1 FUSE)





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






NG -- CHECK FOR SHORT IN ALL HARNESS AND CONNECTOR CONNECTED TO FUSE AND REPLACE FUSE
OK -- Continue to next step.

2. INSPECT VSC NO.2 RELAY





(a) Remove the VSC No. 2 relay.
(b) Measure the resistance according to the value(s) in the table below.
Resistance:






NG -- REPLACE VSC NO.2 RELAY
OK -- Continue to next step.

3. INSPECT VSC NO.1 RELAY





(a) Remove the VSC No. 1 relay.
(b) Measure the resistance according to the value(s) in the table below.
Resistance:






NG -- REPLACE VSC NO.1 RELAY
OK -- Continue to next step.

4. INSPECT ENGINE ROOM R/B (VSC NO. 1 RELAY POWER SOURCE CIRCUIT)





(a) Remove the VSC No. 1 relay from the engine room R/B.
(b) Turn the ignition switch on (IG).
(c) Measure the voltage according to the value(s) in the table below.
Voltage:






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

5. INSPECT ENGINE ROOM R/B





(a) Remove the VSC No. 1 and No. 2 relays.
(b) Measure the resistance according to the value(s) in the table below.
Resistance:






NG -- REPAIR OR REPLACE ENGINE ROOM R/B
OK -- Continue to next step.

6. CHECK HARNESS AND CONNECTOR (SKID CONTROL ECU TO ENGINE ROOM R/B)





(a) Disconnect the skid control ECU connector.
(b) Remove the VSC No. 1 relay and VSC No. 2 relay from the engine room R/B.
(c) Measure the resistance according to the value(s) in the table below.
Resistance:





(d) Measure the resistance according to the value(s) in the table below.
Resistance:






NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

7. RECONFIRM DTC
(a) Clear the DTC.
(b) Start the engine.
(c) Drive the vehicle at the speed of 4 mph (6 km/h) or more.
(d) Check that the same DTC is recorded.

HINT: Reinstall the sensors, connectors, etc. and restore the vehicle to its prior conditions 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 ignition 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 ABS & TRACTION actuator assembly. Make sure that no DTCs are output.
- If any DTCs are output while jigging a connector or wire harness of the ABS & TRACTION actuator (skid control ECU), inspect and repair the connector or wire harness.

HINT: It is suspected that the DTCs were output due to a bad connection of the connector terminal.

B -- REPLACE ABS & TRACTION ACTUATOR ASSEMBLY
A -- END