Diagnostic Procedure

WARNING: This page is about a different car, the 2004 Nissan Quest. However, it is still accessible from the selected car via links, so may be relevant.

CHECK DTC WITH ECM
- Check P code with CONSULT-II "ENGINE".
- Turn ignition switch ON and select "SELF DIAGNOSTIC RESULTS" mode for "ENGINE" with CONSULT-II.
  Refer to "MALFUNCTION INDICATOR LAMP (MIL) ".
OK or NG
1. OK: (With CONSULT-II): GO TO 2.
2. OK (without CONSULT-II): GO TO 3.
3. NG: Check accelerator pedal position (APP) sensor circuit for engine control. Refer to DTC P2122, P2123: APP SENSOR , DTC P2127, P2128: APP SENSOR , DTC P2138: APP SENSOR .
CHECK INPUT SIGNAL (WITH CONSULT-II)
WITH CONSULT-II
1. Turn ignition switch to ON position. (Do not start engine.)
  
  Fig 1: CONSULT-II Display - DATA MONITOR
  Courtesy of NISSAN MOTOR CO., U.S.A.
2. Select "DATA MONITOR" mode for "A/T" with CONSULT-II.
3. Read out the value of "THRTL POS SEN".
  Voltage:
  
  Fully-closed throttle: Approximately 0.5V
  
  Fully-open throttle: Approximately 4V
OK or NG
1. OK: GO TO 4.
2. NG: Check harness for short or open between ECM and TCM regarding accelerator pedal position signal circuit.
CHECK INPUT SIGNAL (WITHOUT CONSULT-II)
Without CONSULT-II
1. Turn ignition switch to ON position. (Do not start engine.)
  
  Fig 2: Checking Voltage Between TCM Connector Terminals 41 And 42
  Courtesy of NISSAN MOTOR CO., U.S.A.
2. Check voltage between TCM harness connector E143 terminals 41 (W) and 42 (B) while accelerator pedal is depressed slowly.
  Voltage:
  
  Fully-closed throttle valve: Approximately 0.5V
  
  Fully-open throttle valve: Approximately 4V
  
  (Voltage rises gradually in response to throttle position.)
OK or NG
1. OK: GO TO 4.
2. NG: Check harness for short or open between ECM and TCM regarding accelerator pedal position signal circuit.
CHECK TCM INSPECTION
1. perform TCM input/output signal inspection. Refer to "TCM TERMINALS AND REFERENCE VALUE ".
2. If NG, recheck TCM pin terminals for damage or loose connection with harness connector.
OK or NG
1. OK: INSPECTION END
2. NG: Repair or replace damaged parts.