Toyota Corolla Cross Owners & Service Manuals

Toyota Corolla Cross: Linear Solenoid Power Supply System Malfunction (C120C)

Toyota Corolla Cross (2022-2025) Service Manual / Drivetrain / Gf1a (transfer / 4wd / Awd) / Dynamic Torque Control Awd System / Linear Solenoid Power Supply System Malfunction (C120C)

DESCRIPTION

When a malfunction has occurred in the linear solenoid power source circuit, the 4WD ECU assembly stores DTC C120C.

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

C120C

Linear Solenoid Power Supply System Malfunction
  • When the 4WD relay is on and the voltage at the IG1 terminal is 9.5 V or more, the 4WD relay monitor remains off for 1 second or more.
  • When the 4WD relay is on and the voltage at the IG1 terminal is less than 9.5 V, 1 second or more elapses without the 4WD relay monitor turning on.
  • When the 4WD relay is off, the 4WD relay monitor remains on for 1 second or more immediately after the ignition switch is turned to ON.
  • Wire harness or connector
  • 4WD ECU assembly

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

Inspect the fuses for circuits related to this system before performing the following inspection procedure.

PROCEDURE

1.

CHECK HARNESS AND CONNECTOR (IG1 TERMINAL)

(a) Disconnect the 4WD ECU assembly connector.

*a

Front view of wire harness connector

(to 4WD ECU Assembly)

(b) Turn the ignition switch to ON.

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

Standard Voltage:

Tester Connection

Switch Condition

Specified Condition

O201-3 (IG1) -Body ground

Ignition switch ON

11 to 14 V
NG

REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

2.

CHECK HARNESS AND CONNECTOR (GND TERMINAL)

(a) Turn the ignition switch off.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

O201-4 (GND) -Body ground

Always

Below 1 Ω
NG

REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

3.

RECONFIRM DTC

(a) Clear the DTC.

Chassis > Four Wheel Drive > Clear DTCs

(b) Turn the ignition switch to ON.

(c) Check that no DTCs other than DTC C120C have been output.

Chassis > Four Wheel Drive > Trouble Codes

Result

Proceed to

DTCs other than C120C are not output

A

DTCs other than C120C are output

B
A

REPLACE 4WD ECU ASSEMBLY

B

REPAIR CIRCUIT INDICATED BY OUTPUT CODE

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