Dtc C146C Open In Abs Motor Relay Circuit

Brake. Yaris. Ncp93, 131
Brake Control Dynamic Control Systems. Yaris. Ncp93, 131

DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

PERFORM ACTIVE TEST USING TECHSTREAM (ABS MOTOR RELAY)

CHECK TERMINAL VOLTAGE (+BM TERMINAL)

CHECK HARNESS AND CONNECTOR (GND2 TERMINAL)

RECONFIRM DTC

DTC C146C Open in ABS Motor Relay Circuit

DTC C146D Short in ABS Motor Relay Circuit


DESCRIPTION

The ABS motor relay supplies power to the ABS pump motor. While the ABS is activated, the ECU turns the motor relay on and operates the ABS pump motor.
If the voltage supplied to the motor relay (+BM) is below the DTC's detection threshold due to low voltage from the battery or generator, the DTC may be stored.

DTC No.
DTC Detection Condition
Trouble Area
C146C
When either of the following is detected:
  1. All of the following conditions continue for 0.12 seconds or more.
    1. The IG1 terminal voltage is between 9.5 and 17.2 V.
    2. While initial check and ABS, BA, TRAC or VSC is operating.
    3. Relay contact is open when the relay is ON.
  2. Both of the following conditions continue for 0.12 seconds.
    1. The IG1 terminal voltage is less than 9.5 V.
    2. Relay contact remains open when the relay is ON.
  1. ABS NO. 1 fuse
  2. ABS motor relay circuit
  3. Brake actuator assembly (ABS motor relay)
C146D
When the motor relay is OFF, the motor relay remains closed for 4 seconds or more.
  1. ABS motor relay circuit
  2. Brake actuator assembly (ABS motor relay)

WIRING DIAGRAM


Yaris. Ncp93, 131.Brake Control Dynamic Control Systems.Anti-Lock Brake System (For Sedan). Dtc C146C Open In Abs Motor Relay Circuit


INSPECTION PROCEDURE

NOTICE:
Inspect the fuses for circuits related to this system before performing the following inspection procedure.
HINT:
When C1241 is output together with C146C and/or C146D inspect and repair the trouble areas indicated by C1241 first (YARIS_NCP93 RM000000XW60CDX.html).
1.PERFORM ACTIVE TEST USING TECHSTREAM (ABS MOTOR RELAY)

  1. Connect the Techstream to the DLC3.

  1. Start the engine.

  1. Turn the Techstream on.

  1. Clear the DTC (YARIS_NCP93 RM000000XHV0CPX.html).

  1. Enter the following menu: Chassis / ABS/VSC/TRAC / Active Test.

    ABS/VSC/TRAC
    Tester Display
    		Test Part
    		Control Range
    		Diagnostic Note
    Motor Relay
    		ABS motor relay
    		Relay ON / OFF
    		Operating sound of motor can be heard.

  1. Check the operating sound of the ABS motor relay when operating it with the Techstream.

Result
Result
Proceed to
The operating sound is not heard
A
The operating sound is heard
B


B
Go to step 4
A


2.CHECK TERMINAL VOLTAGE (+BM TERMINAL)

  1. Turn the ignition switch off.

  1. Make sure that there is no looseness at the locking part and the connecting part of the connectors.

  1. Check the connector case and terminals for deformation and corrosion.

    OK:
    No deformation or corrosion.


    Yaris. Ncp93, 131.Brake Control Dynamic Control Systems.Anti-Lock Brake System (For Sedan). Dtc C146C Open In Abs Motor Relay Circuit

  1. Disconnect the skid control ECU connector.

  1. Measure the voltage according to the value(s) in the table below.

    Standard Voltage:
    Tester Connection
    		Condition
    		Specified Condition
    A71-24 (+BM) - Body ground
    		Always
    		11 to 14 V
    Text in Illustration
    *a
    		Front view of wire harness connector
    (to Skid control ECU)

  1. Turn the ignition switch off.



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR (+BM CIRCUIT)
OK


3.CHECK HARNESS AND CONNECTOR (GND2 TERMINAL)


    Yaris. Ncp93, 131.Brake Control Dynamic Control Systems.Anti-Lock Brake System (For Sedan). Dtc C146C Open In Abs Motor Relay Circuit

  1. Measure the resistance according to the value(s) in the table below.

    Standard Resistance:
    Tester Connection
    		Condition
    		Specified Condition
    A71-13 (GND2) - Body ground
    		Always
    		Below 1 Ω
Text in Illustration
*a
Front view of wire harness connector
(to Skid control ECU)


NG
REPAIR OR REPLACE HARNESS OR CONNECTOR (GND CIRCUIT)
OK


4.RECONFIRM DTC
HINT:
These codes are detected when a problem is determined in the skid control ECU (brake actuator assembly).
The solenoid circuits are in the skid control ECU (brake actuator assembly).
Therefore, solenoid circuit inspection and solenoid unit inspection cannot be performed. Be sure to check if any DTCs are output before replacing the skid control ECU (brake actuator assembly).

  1. Clear the DTC (YARIS_NCP93 RM000000XHV0CPX.html).

  1. Start the engine.

  1. Drive the vehicle at the speed of 20 km/h (12 mph) or more for 30 seconds or more.

  1. Check if the same DTC is recorded (YARIS_NCP93 RM000000XHV0CPX.html).

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


B
REPLACE BRAKE ACTUATOR ASSEMBLY (YARIS_NCP93 RM000001BXP02KX.html)
A

CHECK FOR INTERMITTENT PROBLEMS (SYMPTOM SIMULATION) (YARIS_NCP93 RM000000XHS0AMX.html)