Nissan Maxima Service and Repair Manual: DTC/circuit diagnosis

  • Power supply and ground circuit
  • POWER SUPPLY AND GROUND CIRCUIT AUDIO UNIT AUDIO UNIT : Diagnosis Procedure 1.CHECK FUSES Check that the following fuses are not blown. 2.POWER SUPPLY CIRCUIT CHECK Disconnect audio unit connector M133. Check voltage between the audio unit connector M133 and ground. 3.GROUND CIRCUIT CHECK Inspect audio unit case ground. SUBWOOFER AMP SUBWOOFER AMP : Diagnosis Procedure 1.CHECK FUSE Check for blown fuses. 2.CHECK POWER SUPPLY CIRCUIT Turn ignition switch OFF. Disconnect subwoofer amp connector. Check voltage between subwoofer amp harness connector and ground. 3.CHECK GROUND CIRCUIT Check continuity between subwoofer amp harness connector and ground.

  • Front door speaker 
  • Description  The audio unit sends audio signals to the front door speakers using the front door speaker circuits. Diagnosis Procedure  1.CONNECTOR CHECK Check the audio unit and speaker connectors for the following: Proper connection Damage Disconnected or loose terminals 2.HARNESS CHECK Disconnect audio unit connector M133 (A) and suspect speaker connector (B). Check continuity between audio unit harness connector M133 (A) terminal and suspect speaker harness connector (B) terminal.    Check continuity between audio unit harness connector M133 (A) terminal and ground.    3.FRONT DOOR SPEAKER SIGNAL CHECK Connect audio unit connector and front speaker connector.

  • Tweeter 
  • Description  The audio unit sends audio signals to the tweeters using the front door speaker circuits. Diagnosis Procedure 1.CONNECTOR CHECK Check the audio unit and speaker connectors for the following: Proper connection Damage Disconnected or loose terminals 2.HARNESS CHECK Disconnect audio unit connector M133 (A) and suspect tweeter connector (B). Check continuity between audio unit harness connector M133 (A) and suspect tweeter harness connector (B). Check continuity between audio unit harness connector M133 (A) and ground. 3.TWEETER SIGNAL CHECK Connect audio unit connector and tweeter connector. Turn ignition switch to ACC. Push POWER switch.

  • Rear door speaker
  • Description The audio unit sends audio signals to the rear door speakers using the rear door speaker circuits. Diagnosis Procedure 1.CONNECTOR CHECK Check the audio unit and speaker connectors for the following: Proper connection Damage Disconnected or loose terminals 2.HARNESS CHECK Disconnect audio unit connector M133 (A) and suspect speaker connector. Check continuity between audio unit harness connector M133 (A) and suspect speaker harness connector (B). Check continuity between audio unit harness connector M133 (A) and ground. 3.REAR DOOR SPEAKER SIGNAL CHECK Connect audio unit connector and rear door speaker connector. Turn ignition switch to ACC. Push POWER switch.

  • Subwoofer
  • Description The audio unit sends audio signals to the subwoofer amp. The subwoofer amp. amplifies the audio signals before sending them to the subwoofers using the audio signal circuits. Diagnosis Procedure 1.CONNECTOR CHECK Check the audio unit, subwoofer amp. and subwoofer connectors for the following: Proper connection Damage Disconnected or loose terminals 2.HARNESS CHECK Disconnect subwoofer amp. connector B21 and suspect subwoofer connector. Check continuity between subwoofer amp. harness connector B21 (A) and suspect subwoofer harness connector (B). Check continuity between subwoofer harness connector B21 (A) and ground. 3.REAR SUBWOOFER SIGNAL CHECK Connect subwoofer amp.

  • Steering switch
  • Description When one of the steering wheel audio control switches is pushed, the resistance in steering switch circuit changes depending on which button is pushed. Diagnosis Procedure 1.CHECK STEERING SWITCH RESISTANCE Disconnect steering switch connector M88. Check resistance between steering switch connector terminals. 2.CHECK HARNESS BETWEEN COMBINATION SWITCH (SPIRAL CABLE) AND BLUETOOTH CONTROL UNIT Turn ignition switch OFF. Disconnect Bluetooth control unit connector B126 and combination switch (spiral cable) connector M30 Check continuity between Bluetooth control unit harness connector B126 and combination switch (spiral cable) harness connector M30.

  • Microphone signal circuit
  • Description Voice signals are transmitted from the microphone to the Bluetooth control unit using the microphone signal circuits. Diagnosis Procedure 1.CHECK HARNESS BETWEEN BLUETOOTH CONTROL UNIT AND MICROPHONE Turn ignition switch OFF. Disconnect Bluetooth control unit connector and microphone connector. Check continuity between Bluetooth control unit harness connector B126 (A) and microphone harness connector R7 (B) Check continuity between Bluetooth control unit harness connector B126 (A) and ground. 2.CHECK MICROPHONE POWER SUPPLY Connect Bluetooth control unit connector and microphone connector. Turn ignition switch ON.

Diagnosis system (bluetooth control unit)

Power supply and ground circuit