Open 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 related to the motor line is stored, the VSC FAIL (fail-safe) relay cuts off the power supply to the VSC MTR relay and performs the fail-safe operation.
While the ABS, TRAC, VSC, or BA is operating, the skid control ECU turns the VSC FAIL relay on and activates the pump motor in the ABS and TRACTION actuator.
These DTCs 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.





HINT: DTCs C0273/13, C0274/14 and C1361/91: The skid control ECU begins to detect these DTCs when the vehicle speed exceeds 6 km/h (4 mph).

WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

1. PERFORM ACTIVE TEST USING TECHSTREAM (MOTOR RELAY)
(a) Select the Active Test, generate a control command, and then check that the ABS motor relay operates.

ABS / VSC / TRAC:





OK:
The operation sound of the ABS motor can be heard.
OK -- RECONFIRM DTC
NG -- Continue to next step.
2. INSPECT FUSE (ABS1)
(a) Remove the ABS1 H-fuse from the engine room No. 1 relay block.
(b) Measure the resistance of the fuse.
Standard resistance:
Below 1 Ohms
NG -- REPLACE FUSE
OK -- Continue to next step.
3. INSPECT VSC MOTOR RELAY (Marking: VSC MTR)





(a) Remove the VSC motor relay from the engine room No. 1 relay block.
(b) Measure the resistance of the relay.
Standard resistance:






NG -- REPLACE VSC MOTOR RELAY
OK -- Continue to next step.
4. INSPECT FAIL-SAFE RELAY (Marking: VSC FAIL)





(a) Remove the faile-safe relay from the engine room No. 1 relay block.
(b) Measure the resistance of the relay.
Standard resistance:






NG -- REPLACE FAIL-SAFE RELAY
OK -- Continue to next step.
5. CHECK WIRE HARNESS (FAIL-SAFE RELAY - BATTERY)





(a) Remove the fail-safe relay from the engine room No. 1 relay block.
(b) Measure the voltage of the wire harness side connector.
Standard voltage:






NG -- REPAIR OR REPLACE HARNESS AND CONNECTOR
OK -- Continue to next step.
6. CHECK ENGINE ROOM NO. 1 RELAY BLOCK (FAIL-SAFE RELAY - VSC MOTOR RELAY AND BODY GROUND)





(a) Remove the fail-safe and VSC motor relays from the engine room No. 1 relay block.
(b) Measure the resistance of the relay terminals.
Standard resistance:






NG -- REPLACE ENGINE ROOM NO. 1 RELAY BLOCK
OK -- Continue to next step.
7. CHECK WIRE HARNESS (ENGINE ROOM NO. 1 RELAY BLOCK - SKID CONTROL ECU)





(a) Disconnect the A19 ECU connector.
(b) Remove the fail-safe and VSC motor relays from the engine room No. 1 relay block.
(c) Measure the resistance of the wire harness connectors.
Standard resistance:






NG -- REPAIR OR REPLACE HARNESS AND CONNECTOR
OK -- Continue to next step.
8. RECONFIRM DTC
(a) Clear the DTC(s) .
(b) Start the engine.
(c) Drive the vehicle at 6 km/h (4 mph) or more to activate the initial check.
(d) Check if the same DTC(s) is output .

Result





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