Diagnostic Procedure

WARNING: This page is about a different car, the 2005 Infiniti G35. However, it is still accessible from the selected car via links, so may be relevant.

CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten two ground screws on the body. Refer to Ground Inspection .
  
  Fig 1: Checking Ground Connections (DTC P2138 APP Sensor)
  Courtesy of NISSAN MOTOR CO., U.S.A.
OK or NG
1. OK: GO TO 2.
2. NG: Repair or replace ground connections.
CHECK APP SENSOR 1 POWER SUPPLY CIRCUIT
1. Disconnect accelerator pedal position (APP) sensor harness connector.
2. Turn ignition switch ON.
  
  Fig 2: Locating Accelerator Pedal Position (APP) Sensor Harness Connector
  Courtesy of NISSAN MOTOR CO., U.S.A.
3. Check voltage between APP sensor terminal 6 and ground with CONSULT-II or tester.
  1. Voltage: Approximately 5V
OK or NG
1. OK: GO TO 4
2. NG: GO TO 3.
Fig 3: Checking Voltage Between APP Sensor Terminal 6 & Ground
Courtesy of NISSAN MOTOR CO., U.S.A.
DETECT MALFUNCTIONING PART
Check the following.
- Harness connectors E10, F1
- Harness for open or short between ECM and APP sensor
  1. Repair open circuit or short to ground or short to power in harness or connectors.
CHECK APP SENSOR 2 POWER SUPPLY CIRCUIT-I
Check voltage between APP sensor terminal 4 and ground with CONSULT-II or tester.
1. Voltage: Approximately 5V
OK or NG
1. OK: GO TO 10.
2. NG: GO TO 5.
Fig 4: Checking Voltage Between APP Sensor Terminal 4 & Ground
Courtesy of NISSAN MOTOR CO., U.S.A.
CHECK APP SENSOR 2 POWER SUPPLY CIRCUIT-II
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between APP sensor terminal 4 and ECM terminal 91. Refer to Wiring Diagram.
  1. Continuity should exist.
OK or NG
1. OK: GO TO 7
2. NG: GO TO 6.
DETECT MALFUNCTIONING PART
Check the following.
- Harness connectors E10, F1
- Harness for open between ECM and APP sensor
  1. Repair or replace open circuit.

CHECK APP SENSOR 2 POWER SUPPLY CIRCUIT-III

Check harness for short to power and short to ground, between the following terminals.

APP SENSOR 2 POWER SUPPLY CIRCUIT-III ECM SENSOR TERMINAL

ECM terminal	Sensor terminal	Reference
47	Electric throttle control actuator terminal 1	Wiring Diagram - TPS3
91	APP sensor terminal 4	Wiring Diagram - APPS3

OK or NG

OK: GO TO 8.
NG: Repair short to ground or short to power in harness or connectors.

CHECK THROTTLE POSITION SENSOR
Refer to Component Inspection .

OK or NG
1. OK: GO TO 16.
2. NG: GO TO 9.
REPLACE ELECTRIC THROTTLE CONTROL ACTUATOR
1. Replace the electric throttle control actuator.
2. Perform Throttle Valve Closed Position Learning .
3. Perform Idle Air Volume Learning .
  1. : INSPECTION END
CHECK APP SENSOR GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between the following;
  APP sensor terminal 1 and ECM terminal 83,
  
  APP sensor terminal 3 and ECM terminal 82.
  
  Refer to Wiring Diagram.
  1. Continuity should exist.
4. Also check harness for short to ground and short to power.
OK or NG
1. OK: GO TO 12.
2. NG: GO TO 11.
DETECT MALFUNCTIONING PART
Check the following.
- Harness connectors E10, F1
- Harness for open or short between ECM and APP sensor
  1. Repair open circuit or short to ground or short to power in harness or connectors.
CHECK APP SENSOR INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Check harness continuity between the following;
  ECM terminal 106 and APP sensor terminal 5,
  
  ECM terminal 98 and APP sensor terminal 2.
  
  Refer to Wiring Diagram.
  1. Continuity should exist.
2. Also check harness for short to ground and short to power.
OK or NG
1. OK: GO TO 14.
2. NG: GO TO 13.
DETECT MALFUNCTIONING PART
Check the following.
- Harness connectors E10, F1
- Harness for open or short between ECM and APP sensor
  1. Repair open circuit or short to ground or short to power in harness or connectors.
CHECK APP SENSOR
Refer to Component Inspection .

OK or NG
1. OK: GO TO 16.
2. NG: GO TO 15.
REPLACE ACCELERATOR PEDAL ASSEMBLY
1. Replace accelerator pedal assembly.
2. Perform Accelerator Pedal Released Position Learning .
3. Perform Throttle Valve Closed Position Learning .
4. Perform Idle Air Volume Learning .
  1. INSPECTION END
CHECK INTERMITTENT INCIDENT
Refer to TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT .
1. INSPECTION END