Diagnosis Procedure

WARNING: This page is about a different car, the 2020 Infiniti QX60. However, it is still accessible from the selected car via links, so may be relevant.

CHECK DTC PRIORITY
If DTC P2122 or P2123 is displayed with DTC P0643, first perform the confirmation procedure (trouble diagnosis) for DTC P0643.

Is DTC P0643 detected?

YES

Perform diagnosis for P0643. Refer to DTC Description .

NO

GO TO 2.

CHECK APP SENSOR 1 POWER SUPPLY

Disconnect accelerator pedal position (APP) sensor harness connector.
Turn ignition switch ON.

Check the voltage between APP sensor harness connector and ground.

+		-	Voltage (Approx.)
APP sensor
Connector	Terminal
E31 ^*1	5	Ground	5 V
E74 ^*2	10

*1: Without ICC

*2: With ICC

Is the inspection result normal?

YES

GO TO 4.

GO TO 3.

CHECK APP SENSOR 1 POWER SUPPLY CIRCUIT

Turn ignition switch OFF.
Disconnect ECM harness connector.

Check the continuity between APP sensor harness connector and ECM harness connector.

APP sensor		ECM		Continuity
Connector	Terminal	Connector	Terminal
E31 ^*1	5	E32	198	Existed
E74 ^*2	10

*1: Without ICC

*2: With ICC

Also check harness for short to power and short to ground.

Is the inspection result normal?

YES

Perform the trouble diagnosis for ECM power supply circuit. Refer to Diagnosis Procedure .

Repair or replace error-detected parts.

CHECK APP SENSOR 1 GROUND CIRCUIT

Turn ignition switch OFF.
Disconnect ECM harness connector.

Check the continuity between APP sensor harness connector and ECM harness connector.

APP sensor		ECM		Continuity
Connector	Terminal	Connector	Terminal
E31 ^*1	4	E32	203	Existed
E74 ^*2	4

*1: Without ICC

*2: With ICC

Also check harness for short to power.

Is the inspection result normal?

YES

GO TO 5.

Repair or replace error-detected parts.

CHECK APP SENSOR INPUT SIGNAL CIRCUIT

Check the continuity between APP sensor harness connector and ECM harness connector.

APP sensor		ECM		Continuity
Connector	Terminal	Connector	Terminal
E31 ^*1	3	E32	202	Existed
E74 ^*2	6

*1: Without ICC

*2: With ICC

Also check harness for short to power and short to ground.

Is the inspection result normal?

YES

GO TO 6.

Repair or replace error-detected parts.

CHECK APP SENSOR
Refer to Component Inspection (Accelerator Pedal Position Sensor) .

Is the inspection result normal?

YES

INSPECTION END

NO

Replace accelerator pedal assembly. Refer to Removal and Installation (models without distance control assist system), Removal and Installation (models with distance control assist system).