ABS (Anti-Lock Brake System)

BRAKE CONTROL: ANTI-LOCK BRAKE SYSTEM: C1251/51: Open in Pump Motor Circuit

DTC C1251/51 - Open in Pump Motor Circuit

DESCRIPTION





WIRING DIAGRAM






INSPECTION PROCEDURE

PROCEDURE

1. PERFORM ACTIVE TEST USING TECHSTREAM (ABS MOTOR RELAY)
(a) Connect the Techstream to the DLC3.
(b) Start the engine.
(c) Select the Active Test mode on the Techstream Data List / Active Test.

ABS/VSC/TRAC:





(d) Check the operating sound of the ABS motor relay when operating it with the Techstream.
Result:






B -- RECONFIRM DTC
A -- Continue to next step.
2. INSPECT SKID CONTROL ECU (GND TERMINAL)




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






NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (GND CIRCUIT)
OK -- Continue to next step.
3. RECONFIRM DTC
HINT:
This code is detected when a problem is identified in the brake actuator assembly.
The ABS motor relay is in the brake actuator assembly.
Therefore, ABS motor relay inspection and motor relay unit inspection cannot be performed. Be sure to check if the DTC in output before replacing the brake actuator assembly.
(a) Turn the ignition switch to OFF.
(b) Reconnect the skid control ECU connector.
(c) Clear the DTC ABS (Antilock Brake System).
(d) Start the engine.
(e) Drive the vehicle at a speed of 20 km/h (12 mph) or more for 30 seconds or more.
(f) Check if the same DTC is recorded ABS (Antilock Brake System).
Result:





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

B -- REPLACE BRAKE ACTUATOR ASSEMBLY
A -- CHECK FOR INTERMITTENT PROBLEMS (SYMPTOM SIMULATION)