LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Infiniti >> 2004 >> FX45 >> Repair and Diagnosis >> Engine Performance >> Engine Control System >> DTC P1564 ASCD Steering Switch >> Diagnostic Procedure
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Diagnostic Procedure

  1. Check Ground Connections 
    1. Turn ignition switch OFF.
    2. Loosen and retighten three ground screws on the body. See Figure .

      Refer to GROUND INSPECTION  .

    OK or NG

    1. OK: go to 2.
    2. NG: Repair or replace ground connections.

  2. Check ASCD Steering Switch Circuit 

    With CONSULT-II 

    1. Turn ignition switch ON.
    2. Select MAIN SW , RESUME/ACC SW , SET SW and CANCEL SW in DATA MONITOR mode with CONSULT-II.
    3. Check each item indication under the following conditions.
      Fig 1: Testing ASCD Steering Switch Circuit (CONSULT-II)
      G00345352Courtesy of NISSAN MOTOR CO., U.S.A.
      Fig 2: ASCD Steering Switch Specifications (CONSULT-II)
      G00345351Courtesy of NISSAN MOTOR CO., U.S.A.

    Without CONSULT-II 

    1. Turn ignition switch ON.
    2. Check voltage between ECM terminal 99 and ground with pressing each button.
      Fig 3: Testing ASCD Steering Switch Circuit Voltage (W/DVOM)
      G00345354Courtesy of NISSAN MOTOR CO., U.S.A.
      Fig 4: ASCD Steering Switch Voltage Specifications (W/DVOM)
      G00345353Courtesy of NISSAN MOTOR CO., U.S.A.

    OK or NG

    1. OK: go to  8 .
    2. NG: go to 3.

  3. Check ASCD Steering Switch Ground Circuit For Open And Short 
    1. Turn ignition switch OFF.
    2. Disconnect ECM harness connector.
    3. Disconnect combination switch harness connector.
    4. Check harness continuity between combination switch terminal 15 and ECM terminal 82.

      Refer to wiring diagram. See Figure .

      1. Continuity should exist  .
    5. Also check harness for short to ground and short to power.

    OK or NG

    1. OK: go to  5 .
    2. NG: go to 4.

  4. Detect Malfunctioning Part 

    Check the following.

    • Combination switch (spiral cable)
    • Harness for open and short between ECM and combination switch
      1. Repair open circuit or short to ground or short to power in harness or connectors.
  5. Check ASCD Steering Switch Input Signal Circuit For Open And Short 
    1. Check harness continuity between ECM terminal 99 and combination switch terminal 14.

      Refer to wiring diagram. See Figure .

      1. Continuity should exist  .
    2. Also check harness for short to ground and short to power.

    OK or NG

    1. OK: go to  7 .
    2. NG: go to 6.
  6. Detect Malfunctioning Part 

    Check the following.

    • Combination switch (spiral cable)
    • Harness for open and short between ECM and combination switch
      1. Repair open circuit or short to ground or short to power in harness or connectors.

  7. Check ASCD Steering Switch 

    Refer to COMPONENT INSPECTION  .

    OK or NG

    1. OK: go to 8.
    2. NG: Replace ASCD steering switch.

  8. Check Intermittent Incident 

    Refer to TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT  .

    1. Inspection end