Dtc C1242 Open Circuit In Ig1/Ig2 Power Source Circuit

Brake. Land Cruiser. Urj200, 202 Grj200 Vdj200
Brake Control Dynamic Control Systems. Land Cruiser. Urj200, 202 Grj200 Vdj200

DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

CHECK HARNESS AND CONNECTOR (IG2 TERMINAL)

CHECK HARNESS AND CONNECTOR (GND1, GND2 AND GND3 TERMINAL)

RECONFIRM DTC

DTC C1242 Open Circuit in IG1/IG2 Power Source Circuit


DESCRIPTION

If there is a problem with the skid control ECU (master cylinder solenoid) power supply circuit, the skid control ECU (master cylinder solenoid) stores DTCs and prohibits operation under the fail-safe function.
If the voltage supplied to the IG2 terminal is within the DTC detection range due to malfunctions in components such as the battery and generator circuit, this DTC is stored.

DTC Code
DTC Detection Condition
Trouble Area
C1242
The vehicle speed is 3 km/h (2 mph) or more and the voltage at the ECU IG2 terminal remains below 6.5 V for more than 7 seconds.
  1. Battery
  2. IG2 NO. 1 fuse
  3. Charging system
  4. Harness or connector
  5. Skid control ECU (Master cylinder solenoid)

WIRING DIAGRAM


Land Cruiser. Urj200, 202 Grj200 Vdj200.Brake Control Dynamic Control Systems.Anti-Lock Brake System. Dtc C1242 Open Circuit In Ig1/Ig2 Power Source Circuit


INSPECTION PROCEDURE

NOTICE:
  1. After replacing the master cylinder solenoid, perform zero point calibration (Click here).
  2. Inspect the fuses for circuits related to this system before performing the following inspection procedure.
1.CHECK HARNESS AND CONNECTOR (IG2 TERMINAL)

  1. Turn the ignition switch off.

  1. Disconnect the skid control ECU (master cylinder solenoid) connector.



    Land Cruiser. Urj200, 202 Grj200 Vdj200.Brake Control Dynamic Control Systems.Anti-Lock Brake System. Dtc C1242 Open Circuit In Ig1/Ig2 Power Source Circuit

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

    Standard Voltage:
    Tester Connection
    		Switch Condition
    		Specified Condition
    A25-1 (IG2) - Body ground
    		Ignition switch ON
    		11 to 14 V
    Text in Illustration
    *a
    		Front view of wire harness connector
    (to Skid Control ECU [Master Cylinder Solenoid])


NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


2.CHECK HARNESS AND CONNECTOR (GND1, GND2 AND GND3 TERMINAL)
Land Cruiser. Urj200, 202 Grj200 Vdj200.Brake Control Dynamic Control Systems.Anti-Lock Brake System. Dtc C1242 Open Circuit In Ig1/Ig2 Power Source Circuit

  1. Turn the ignition switch off.

  1. Disconnect the skid control ECU (master cylinder solenoid) connectors.

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

    Standard Resistance:
    Tester Connection
    		Condition
    		Specified Condition
    A24-1 (GND1) - Body ground
    		Always
    		Below 1 Ω
    A24-32 (GND2) - Body ground
    		Always
    		Below 1 Ω
    A25-4 (GND3) - Body ground
    		Always
    		Below 1 Ω
    Text in Illustration
    *a
    		Front view of wire harness connector
    (to Skid Control ECU [Master Cylinder Solenoid])


NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


3.RECONFIRM DTC

  1. Clear the DTCs (Click here).

  1. Turn the ignition switch off.

  1. Check if the same DTC is output (Click here).

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

    Result
    Result
    		Proceed to
    DTC is not output
    		A
    DTC is output (for LHD)
    		B
    DTC is output (for RHD)
    		C


B
REPLACE MASTER CYLINDER SOLENOID (Click here)

C
REPLACE MASTER CYLINDER SOLENOID (Click here)
A

CHECK FOR INTERMITTENT PROBLEMS (Click here)