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Home >> Infiniti >> 2012 >> QX56 AWD >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System - DTCS U0101 To P0153 >> DTC U1024: Can Comm Circuit >> Diagnosis Procedure

Diagnosis Procedure

  1. CHECK VVEL CAN COMMUNICATION CIRCUIT
    1. Turn ignition switch OFF.
    2. Disconnect ECM harness connector.
    3. Disconnect VVEL control module harness connector.
    4. Check the continuity between ECM harness connector and VVEL control module harness connector.
      ECM VVEL control module Continuity
      Connector Terminal Connector Terminal
      E80 161 F56 24 Existed
      166 11
    5. Also check harness for short to ground and short to power.

    Is the inspection result normal? 

    YES: GO TO  3.

    NO: GO TO 2.

  2. DETECT MALFUNCTIONING PART

    Check the following.

    • Harness for open or short between ECM and VVEL control module
    • Loose or poor connection for each connector and harness

    : Repair open circuit, short to ground or short to power in harness or connectors.

  3. CHECK INTERMITTENT INCIDENT

    Refer to "INTERMITTENT INCIDENT ".

    Is the inspection result normal? 

    YES: GO TO 4.

    NO: Repair or replace.

  4. REPLACE VVEL CONTROL MODULE
    1. Replace VVEL control module.
    2. Perform additional service when replacing VVEL control module. Refer to "WORK PROCEDURE ".

    : GO TO 5.

  5. PERFORM DTC CONFIRMATION PROCEDURE

    WITH CONSULT

    1. Reconnect all harness connectors disconnected.
    2. Turn ignition switch ON.
    3. Select "SELF DIAGNOSTIC RESULT" mode with CONSULT.
    4. Touch "ERASE".
    5. Perform DTC Confirmation Procedure.

      See "DTC LOGIC ".

    WITH GST

    1. Reconnect all harness connectors disconnected.
    2. Turn ignition switch ON.
    3. Select Service $04 with GST.
    4. Perform DTC Confirmation Procedure.

      See "DTC LOGIC ".

    Is the DTC U1024 displayed again? 

    YES: GO TO 6.

    NO: INSPECTION END

  6. REPLACE ECM
    1. Replace ECM.
    2. Perform additional service when replacing ECM. Refer to "WORK PROCEDURE ".

    : INSPECTION END