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Home >> Infiniti >> 2017 >> QX30 Luxury, AWD >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System (DTCS) (1 Of 5) >> DTC/Circuit Diagnosis >> DTC U0121: Can Communication (Electronic Stability Program Control Unit) >> Diagnosis Procedure >> Diagnostic Test
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Diagnostic Test

  1. CHECK SELF-DIAGNOSTIC RESULT

    G-20 With CONSULT

    1. Perform "All DTC reading".
    2. Check DTC of "ABS".

    Is the DTC related to "communication error with ECM" detected?

    YES 

    GO TO STEP 2  .

    NO 

    Replace ECM. Refer to REMOVAL AND INSTALLATION .

  2. CHECK HARNESS AND CONNECTORS FOR CAN COMMUNICATION

    1. Turn ignition switch OFF.
    2. Disconnect ECM harness connector.
    3. Disconnect the ECU harness connector in which is detecting DTC.
    4. Check the continuity between ECM harness connector and the electronic stability program control unit harness connector.
      + - Continuity
      ECM Electronic stability program control unit
      Connector Terminal Connector Terminal
      E48 137 E46 26 Existed
      150 14
    5. Also check harness for short to battery and short to ground.

    Is the inspection result normal?

    YES 

    GO TO STEP 3  .

    NO 

    Repair or replace error-detected parts.

  3. REPLACE ECM

    G-20 With CONSULT

    1. Replace ECM. Refer to REMOVAL AND INSTALLATION .
    2. Turn ignition switch ON and wait at least 5 seconds.
    3. Check "Self-diagnostic result" of "ENGINE".

    Is DTC "U0121" detected again?

    YES 

    Replace electronic stability program control unit. Refer to REMOVAL AND INSTALLATION .

    NO 

    INSPECTION END