Dtc C1242 Open Circuit In Ig1/Ig2 Power Source Circuit


DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

CHECK TERMINAL VOLTAGE (IG2)

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 master cylinder solenoid (skid control ECU) power supply circuit, the skid control ECU 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. IGN fuse
  3. Charging system
  4. Harness or connector
  5. Master cylinder solenoid (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 C1242 Open Circuit In Ig1/Ig2 Power Source Circuit


INSPECTION PROCEDURE

NOTICE:
  1. When replacing the master cylinder solenoid, perform calibration (LandCruiser RM00000452J00ZX.html).
  2. Inspect the fuses for circuits related to this system before performing the following inspection procedure.
1.CHECK TERMINAL VOLTAGE (IG2)

  1. Disconnect the A8 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 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
    A8-1 (IG2) - Body ground
    		Ignition switch ON
    		11 to 14 V
    Text in Illustration
    *a
    		Front view of wire harness connector
    (to Skid Control ECU)


NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


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

  1. Disconnect the A7 and A8 skid control ECU connectors.

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

    Standard Resistance:
    Tester Connection
    		Condition
    		Specified Condition
    A7-1 (GND1) - Body ground
    		Always
    		Below 1 Ω
    A7-32 (GND2) - Body ground
    		Always
    		Below 1 Ω
    A8-4 (GND3) - Body ground
    		Always
    		Below 1 Ω


NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


3.RECONFIRM DTC

  1. Clear the DTCs (LandCruiser RM0000046KV016X.html).

  1. Check if the same DTC is output (LandCruiser RM0000046KV016X.html).

    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 (LandCruiser RM00000171U02DX.html)

C
REPLACE MASTER CYLINDER SOLENOID (LandCruiser RM00000171U02EX.html)
A

USE SIMULATION METHOD TO CHECK (LandCruiser RM000003YMJ00XX.html)