DTC P18A7-62: Gear Shift Control Module "A"/"B" IGCT Signal Compare Failure [10/2022 - ]: Procedure

Pre-procedure1

• Disconnect the B56 shift control actuator assembly (shift actuator ECU) connector.
• Connect the cable to the negative (-) auxiliary battery terminal.
• Turn the ignition switch to ON.

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

  Standard Voltage

  Tester Connection	Switch Condition	Specified Condition	Result
  B56-5 (IGC1) - Body ground	Ignition switch ON	11 to 14 V	V

  Result

  Proceed to
  OK
  NG

Post-procedure1

• Turn the ignition switch off.
• Disconnect the cable from the negative (-) auxiliary battery terminal.
• Reconnect the shift control actuator assembly (shift actuator ECU) connector.

Result: 

OK 

REPLACE SHIFT CONTROL ACTUATOR ASSEMBLY (SHIFT ACTUATOR ECU). Refer to  REMOVAL [10/2022 - 08/2023]  , or refer to  REMOVAL [08/2023 - ] 

Result: 

NG 

See step  2

Pre-procedure1

• Remove the IGCT NO. 1 relay from the No. 1 engine room relay block and No. 1 junction block assembly.

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

  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

  *1	IGCT NO. 1 Relay

  Standard Resistance

  Tester Connection	Condition	Specified Condition	Result
  3 - 5	Auxiliary battery voltage not applied between terminals 1 and 2	10 kΩ or higher	kΩ
  3 - 5	Auxiliary battery voltage applied between terminals 1 and 2	Below 1 Ω	Ω

  Result

  Proceed to
  OK
  NG

Post-procedure1

• Install the IGCT NO. 1 relay to the No. 1 engine room relay block and No. 1 junction block assembly.

Result: 

OK 

REPAIR OR REPLACE HARNESS OR CONNECTOR (IGCT POWER SUPPLY CIRCUIT) 

Result: 

NG 

REPLACE IGCT NO. 1 RELAY