DTC    C1241/41    Low Battery Positive Voltage

DTC    C1242/42    Open in IG1 / IG2 Power Source Circuit

for Preparation Click here


DESCRIPTION

These codes are memorized when the power source voltage for the skid control ECU drops or the voltage for the ABS MAIN1 relay and ABS MAIN2 relay operation drops.

HINT:
DTC C1256/57 (accumulator low pressure) may be memorized if the power source voltage drops.


DTC No.
INF Code
DTC Detection Condition
Trouble Area
C1241/41
81
After starting the engine, any of the following is detected in the main relay 1 line:
  1. With the main relay 1 and the relay contact ON, the voltage of relay power supply terminal (BS1) is below 8.9 V and the actual current, which is supplied by the relay, does not reach the specified value at any of the linear solenoids for 0.03 seconds or more.
  2. With the main relay 1 and the relay contact ON, the voltage of relay power supply terminal (BS1) is below 8.9 V and the brake pedal is not depressed for 3 seconds or more.
  3. When 0.05 seconds elapsed after main relay 1 is turned on and the relay contact is ON, the voltage of relay power supply terminal (BS1) is below 8.9 V and even one wheel is prohibited from braking while depressing the brake pedal.
  4. While the main relay 1 ON continues, the voltage of relay output terminal (R1+) becomes lower than 8.5 V and the relay contact OFF continues for 0.2 seconds or more.
  5. With the pressure sensor power supply voltage (VCM) 4.7 V or less or 5.3 V or more, the voltage of relay output terminal (R1+) in the relevant lines is 8.5 V or less for 0.05 seconds or more.
  1. Battery
  2. ABS MAIN1 relay
  3. ABS MAIN2 relay
  4. Charging system
  5. Power source circuit
↑
82
After starting the engine, any of the following is detected in the main relay 2 line:
  1. With the main relay 2 and the relay contact ON, the voltage of relay power supply terminal (BS2) is below 8.9 V and the actual current, which is supplied by the relay, does not reach the specified value at any of the linear solenoids for 0.03 seconds or more.
  2. With the main relay 2 and the relay contact ON, the voltage of relay power supply terminal (BS2) is below 8.9 V and the brake pedal is not depressed for 3 seconds or more.
  3. When 0.05 seconds elapsed after main relay 2 is turned on and the relay contact is ON, the voltage of relay power supply terminal (BS2) is below 8.9 V and even one wheel is prohibited from braking while depressing the brake pedal.
  4. While the main relay 2 ON continues, the voltage of relay output terminal (R2+) becomes lower than 8.5 V and the relay contact OFF continues for 0.2 seconds or more.
  5. With the pressure sensor power supply voltage (VCM) 4.7 V or less or 5.3 V or more, the voltage of relay output terminal (R2+) in the relevant lines is 8.5 V or less for 0.05 seconds or more.
↑
↑
83
Capacitor mode signal is received from brake control power supply for 3 seconds or more when starting the engine.
  1. Battery
  2. Charging system
  3. Brake control power supply
↑
91
92
At a vehicle speed of 3 km/h or more, the IG1 terminal voltage is 9.7 or less or R1+ is less than 8.5 V for 10 seconds or more.
  1. Battery
  2. Charging system
  3. Power source circuit
↑
93
94
With the R1+ terminal voltage 8.5 V or more, malfunction in the wheel speed sensor power supply continues for 60 seconds or more.
↑
C1242/42
87
The power supply voltage is not applied to the IG1 terminal (below 3.5 V), power supply voltage is applied to the IG2 terminal (3.5 V or more), and DI1 terminal voltage is 9.5 V or more for 4 seconds or more.
  1. Power source circuit
  2. Skid control ECU
↑
88
The Power supply voltage is applied to the IG1 terminal (3.5 V or more), power supply voltage is not applied to the IG2 terminal (below 3.5 V), and DI1 terminal voltage is 9.5 V or more for 4 seconds or more.
↑

WIRING DIAGRAM


C109403E01


C109404E01


INSPECTION PROCEDURE

NOTICE:
When replacing the skid control ECU, perform initialization of linear solenoid valve and calibration (Click here).

1.INSPECT BATTERY

  1. Check the battery voltage.

    Voltage:
    11 to 14 V



NG
INSPECT CHARGING SYSTEM
OK


2.CHECK DTC

  1. Clear the DTCs (Click here).

  1. Turn the engine switch off.

  1. Turn the engine switch on (IG).

  1. Check that the DTCs (ECB and EFI system) are recorded.

    Result:

    Condition
    		Proceed To
    DTCs (C1311/11, C1312/12, C1313/13, C1314/14 and EFI system malfunction) are not output
    		A
    EFI system DTC is output
    		B (Click here)
    DTCs (C1311/11, C1312/12, C1313/13 and C1314/14) are output
    		C (Click here)



B
REPAIR ENGINE CONTROL SYSTEM ACCORDING TO DTC OUTPUT

C
REPAIR CIRCUIT INDICATED BY OUTPUT CODE
A


3.INSPECT SKID CONTROL ECU (IG AND DI TERMINALS)


    C110724E05

  1. Disconnect the skid control ECU (A13, A15) connectors.

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

    Voltage:
    Tester Connection
    		Condition
    		Specified Condition
    A13-16 (IG1) -
    Body ground
    		Engine switch on (IG)
    		10 to 14 V
    A13-39 (DI1) -
    Body ground
    		Always
    		10 to 14 V
    A15-14 (IG2) -
    Body ground
    		Engine switch on (IG)
    		10 to 14 V
    A15-33 (DI2) -
    Body ground
    		Always
    		10 to 14 V



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR (IG OR DI CIRCUIT)
OK


4.INSPECT SKID CONTROL ECU (GND TERMINAL)


    C110724E06

  1. Disconnect the skid control ECU (A13, A15) connectors.

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

    Resistance:
    Tester Connection
    		Specified Condition
    A13-1 (GND) - Body ground
    		Below 1 Ω
    A15-1 (GND4) - Body ground
    		Below 1 Ω



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


5.RECONFIRM DTC

  1. Clear the DTC (Click here).

  1. Turn the engine switch on (IG).

  1. Check if the same DTCs are recorded (Click here).

    Result:

    Condition
    		Proceed To
    DTCs (C1241/41 and C1242/42) are not output
    		A
    DTCs (C1241/41 and C1242/42) are output
    		B

    HINT:
    If troubleshooting has been carried out according to the PROBLEM SYMPTOMS TABLE, refer back to the table and proceed to the next step (Click here).



B
REPLACE SKID CONTROL ECU
A

END