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

NOTE: When replacing the hydraulic brake booster (master cylinder solenoid), perform zero point calibration Programming and Relearning.

PROCEDURE

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

ABS/VSC/TRAC





(e) Check for an operation sound when operating the relay with the Techstream.
OK:
An operation sound can be heard.
OK -- RECONFIRM DTC

NG -- Continue to next step.

2. INSPECT SKID CONTROL ECU (+BM1, +BM2 TERMINAL)




(a) Disconnect the skid control ECU connectors.
(b) Turn the ignition switch to ON.
(c) Measure the voltage according to the value(s) in the table below.
Standard voltage:





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

3. INSPECT SKID CONTROL ECU (GND TERMINAL)




(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.

4. RECONFIRM DTC
(a) Clear the DTC Reading and Clearing Diagnostic Trouble Codes.
(b) Turn the ignition switch off.
(c) Depress the brake pedal more than 20 times.
(d) Turn the ignition switch to ON.
(e) Wait until the pump motor stops.
(f) Depress the brake pedal several times until the pump motor turns on.
(g) Wait until the pump stops.
(h) Repeat the previous 2 step 3 more times.
(i) Check if the same DTC is detected Reading and Clearing Diagnostic Trouble Codes.

HINT: Reinstall the sensors, connectors, etc. and restore the previous vehicle conditions before rechecking for DTCs.

Result:





B -- CHECK FOR INTERMITTENT PROBLEMS
A -- REPLACE HYDRAULIC BRAKE BOOSTER