Dtc C1241 Low Power Supply Voltage Malfunction


DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

CHECK TERMINAL VOLTAGE (IG1)

CHECK HARNESS AND CONNECTOR (GND1 TERMINAL)

RECONFIRM DTC

DTC C1241 Low Power Supply Voltage Malfunction


DESCRIPTION

If a malfunction is detected in the power supply circuit, the skid control ECU (housed in the actuator assembly) stores this DTC and the fail-safe function prohibits ABS operation.
This DTC is stored when the IG1 terminal voltage deviates from the DTC detection condition due to a malfunction in the power supply or charging circuit, such as the battery or generator circuit, etc.
The DTC is cleared when the IG1 terminal voltage returns to normal.

DTC Code
DTC Detection Condition
Trouble Area
C1241
One of the following conditions is met:
  1. At a vehicle speed of 3 km/h (2 mph) or more, the IG1 terminal voltage is below 9.5 V for 10 seconds or more.
  2. When the solenoid relay remains on and the IG1 terminal voltage is below 9.5 V, the relay contact is open for 0.22 seconds or more.
  3. With the IG1 terminal voltage at 9.5 V or less, the vehicle speed sensor power supply decreases for 60 seconds or more.
  1. ECU-IG NO. 1 fuse
  2. Battery
  3. Charging system
  4. Power source circuit
  5. Internal power supply circuit of the skid control ECU

WIRING DIAGRAM


Land Cruiser, Land Cruiser Prado. Grj150 Trj150,155 Kdj150,155 Lj150, Gdj150,155.Brake Control Dynamic Control Systems.Anti-Lock Brake System. Dtc C1241 Low Power Supply Voltage Malfunction


INSPECTION PROCEDURE

NOTICE:
  1. When replacing the brake actuator assembly, perform calibration (LandCruiser RM000000XHR0BKX.html).
  2. Inspect the fuses for circuits related to this system before performing the following inspection procedure.
1.CHECK TERMINAL VOLTAGE (IG1)

  1. Disconnect the A6 skid control ECU connector.



    Land Cruiser, Land Cruiser Prado. Grj150 Trj150,155 Kdj150,155 Lj150, Gdj150,155.Brake Control Dynamic Control Systems.Anti-Lock Brake System. Dtc C1241 Low Power Supply Voltage Malfunction

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

    Standard Voltage:
    Tester Connection
    		Switch Condition
    		Specified Condition
    A6-34 (IG1) - Body ground
    		Ignition switch ON
    		11 to 14 V
    Text in Illustration
    *a
    		Front view of wire harness connector
    (to Skid Control ECU)


NG
REPAIR OR REPLACE HARNESS OR CONNECTOR (IG1 CIRCUIT)
OK


2.CHECK HARNESS AND CONNECTOR (GND1 TERMINAL)

  1. Disconnect the A6 skid control ECU connector.

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

    Standard Resistance:
    Tester Connection
    		Condition
    		Specified Condition
    A6-1 (GND1) - Body ground
    		Always
    		Below 1 Ω


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


3.RECONFIRM DTC

  1. Reconnect the skid control ECU connector.

  1. Clear the DTCs (LandCruiser RM000000XHV0KEX.html).

  1. Start the engine.

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

  1. Check if the same DTC is output (LandCruiser RM000000XHV0KEX.html).

    Result
    Result
    		Proceed to
    DTC not output
    		A
    DTC output
    		B


B
REPLACE BRAKE ACTUATOR ASSEMBLY (LandCruiser RM0000034UX02TX.html)
A

USE SIMULATION METHOD TO CHECK (LandCruiser RM000003YMJ00XX.html)