C1253

BRAKE CONTROL: VEHICLE STABILITY CONTROL SYSTEM: C1253/53: Pump Motor Relay Malfunction

DTC C1253/53 - Pump Motor Relay Malfunction

DESCRIPTION

The motor relay (semiconductor relay) is built into the master cylinder solenoid and drives the pump motor based on a signal from the skid control ECU.





WIRING DIAGRAM





INSPECTION PROCEDURE

HINT: Start the inspection from step 1 when using Techstream and start from step 3 when not using Techstream.

PROCEDURE

1. PERFORM ACTIVE TEST USING TECHSTREAM (H/B MOTOR RELAY)
(a) Connect Techstream to the DLC3.
(b) Turn the ignition switch to the ON position.
(c) Turn Techstream ON.
(d) Select the Active Test mode on Techstream.

ABS/VSC/TRAC





(e) Check for operation sound of the H/B motor when it is operated with Techstream.
OK:
The operation sound of the H/B motor can be heard.
NG -- INSPECT FUSE (ABS NO. 1)
OK -- Continue to next step.
2. RECONFIRM DTC
(a) Clear the DTCs (Reading and Clearing Diagnostic Trouble Codes).
(b) Turn the ignition switch to OFF.
(c) Depress the brake pedal more than 20 times.
(d) Turn the ignition switch to the ON position.
(e) Wait until the pump motor stops.
(f) Depress the brake pedal several times until the pump motor is turned on.
(g) Wait until the pump stops.
(h) Repeat (f) and (g) three times.
(i) Check if the same DTCs are recorded.





B -- END
A -- REPLACE HYDRAULIC BRAKE BOOSTER
3. INSPECT FUSE (ABS NO. 1)





(a) Remove the ABS NO. 1 fuse from the engine room R/B and J/B.
(b) Measure the resistance of the ABS NO. 1 fuse.
Standard:
Below 1 Ohms
(c) Reinstall the ABS NO. 1.
NG -- CHECK FOR SHORTS IN ALL HARNESSES AND CONNECTORS CONNECTED TO FUSE AND REPLACE FUSE
OK -- Continue to next step.
4. INSPECT SKID CONTROL ECU TERMINAL VOLTAGE (+BM, +BM2 TERMINAL)





(a) Disconnect the skid control ECU connectors.
(b) Measure the voltage.
Standard Voltage:





(c) Reconnect the skid control ECU connectors.
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (+BM1 AND +BM2 CIRCUIT)
OK -- Continue to next step.
5. CHECK HARNESS AND CONNECTOR (SKID CONTROL ECU - BODY GROUND)





(a) Disconnect the skid control ECU connectors.
(b) Measure the resistance.
Standard Resistance:





(c) Reconnect the skid control ECU connectors.
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (GND CIRCUIT)
OK -- Continue to next step.
6. RECONFIRM DTC
(a) Clear the DTCs (Reading and Clearing Diagnostic Trouble Codes).
(b) Turn the ignition switch to OFF.
(c) Depress the brake pedal more than 20 times.
(d) Turn the ignition switch to the ON position.
(e) Wait until the pump motor stops.
(f) Depress the brake pedal several times until the pump motor is turned on.
(g) Wait until the pump stops.
(h) Repeat (f) and (g) three times.
(i) Check if the same DTCs are recorded.





B -- END
A -- REPLACE HYDRAULIC BRAKE BOOSTER