Nissan Maxima Service and Repair Manual: DTC/circuit diagnosis

  • U1000 CAN comm circuit
  • Description CAN (Controller Area Network) is a serial communication line for real time application. It is an on-vehicle multiplex communication line with high data communication speed and excellent error detection ability. Many electronic control units are equipped on a vehicle and each control unit shares information and links with other control units during operation (not independent). In CAN communication, control units are connected with 2 communication lines (CAN-H, CAN-L) allowing a high rate of information transmission with less wiring. Each control unit transmits/receives data but selectively reads required data only. DTC Logic DTC DETECTION LOGIC Diagnosis Procedure 1.

  • U1010 control unit (CAN)
  • Description Initial diagnosis of AV control unit. DTC Logic DTC DETECTION LOGIC Diagnosis Procedure 1.

  • U1200 AV control unit
  • Description Replace the AV control unit if this DTC is displayed. Part name  Description  AV CONTROL UNIT  It is the master unit of the MULTI AV system and it is connected to each control unit by means of communication. It operates each system according to communication signals from the AV control unit. AV control unit includes audio function and vehicle information function. It is connected to ECM and combination meter via CAN communication to obtain necessary information for the vehicle information function. It inputs the automatic brightness ON/OFF signals that are required for the display dimming control.

  • U1216 AV control unit
  • Description Replace the AV control unit if this DTC is displayed. Part name  Description  AV CONTROL UNIT  It is the master unit of the MULTI AV system and it is connected to each control unit by means of communication. It operates each system according to communication signals from the AV control unit. AV control unit includes audio function and vehicle information function. It is connected to ECM and combination meter via CAN communication to obtain necessary information for the vehicle information function. It inputs the automatic brightness ON/OFF signals that are required for the display dimming control.

  • U1218 AV control unit
  • DTC Logic U1219 AV CONTROL UNIT DTC Logic U121A AV CONTROL UNIT DTC Logic   U121B AV CONTROL UNIT DTC Logic U121C AV CONTROL UNIT DTC Logic

  • U121D AV control unit
  • DTC Logic Diagnosis Procedure 1.CHECK PLAYBACK OF A DISK (CD) U121E AV CONTROL UNIT DTC Logic Diagnosis Procedure 1.

  • U1227 AV control unit
  • DTC Logic Diagnosis Procedure 1.

  • U122A AV control unit
  • DTC Logic Diagnosis Procedure 1.PERFORM THE SELF-DIAGNOSIS When U122A is detected, write configuration data with "MULTI AV" of CONSULT.

  • U1232 steering angle sensor
  • DTC Logic Diagnosis Procedure ADJUST THE PREDICTIVE COURSE LINE CENTER POSITION OF THE STEERING ANGLE SENSOR When U1232 is detected, adjust the predictive course line center position of the steering angle sensor.

  • U1243 display unit
  • Description Part name  Description  DISPLAY UNIT  Display image is controlled by the serial communication from AV control unit. Inputs the RGB image signal (RGB, RGB area and RGB synchronizing) from AV control unit and the auxiliary image signal from the auxiliary input jacks. Outputs the synchronizing signals (HP and VP) to the AV control unit  DTC Logic Diagnosis Procedure 1.CHECK DISPLAY UNIT POWER SUPPLY AND GROUND CIRCUIT Check display unit power supply and ground circuit 2.CHECK CONTINUITY OF COMMUNICATION CIRCUIT Turn ignition switch OFF. Disconnect display unit connector and AV control unit connector.

  • U1263 USB
  • DTC Logic Diagnosis Procedure 1.CHECK USB HARNESS Visually check USB harness.

  • U1255 satellite radio tuner
  • Description DTC Logic Diagnosis Procedure 1.CHECK SATELLITE RADIO TUNER POWER SUPPLY AND GROUND CIRCUIT Check satellite radio tuner power supply and ground circuit. 2.CHECK CONTINUITY COMMUNICATION CIRCUIT AND REQUEST SIGNAL CIRCUIT Turn ignition switch OFF. Disconnect AV control unit connector M153 and satellite radio tuner connector B111. Check continuity between AV control unit harness connector M153 (A) and satellite radio tuner harness connector B111 (B). Check continuity between AV control unit harness connector M153 (A) and ground. 3.CHECK AV CONTROL UNIT VOLTAGE Connect AV control unit connector. Turn ignition switch ON.

  • U1300 AV comm circuit
  • Description U1300 is indicated when a communication signal malfunction occurs. U1300 is indicated along with DTCs that identify components connected to the AV control unit through communication lines. Determine the possible malfunction cause from the table below.

  • U1310 AV control unit
  • Description DTC Logic

  • Power supply and ground circuit
  • AV CONTROL UNIT AV CONTROL UNIT : Diagnosis Procedure 1.CHECK FUSES Check that the following fuses of the AV control unit are not blown. 2.POWER SUPPLY CIRCUIT CHECK Disconnect AV control unit connectors M152 and M156. Check voltage between the AV control unit connectors M152 and M156 and ground. 3.GROUND CIRCUIT CHECK Turn ignition switch OFF. Check continuity between AV control unit harness connector and ground. DISPLAY UNIT DISPLAY UNIT : Diagnosis Procedure 1.CHECK POWER SUPPLY CIRCUIT Turn ignition switch to ACC. Check voltage between display unit harness connector M141 and ground. 2.CHECK POWER SUPPLY CIRCUIT Turn ignition switch OFF.

  • RGB (R: red) signal circuit
  • Description Transmit the image displayed with AV control unit with RGB signal to the display unit. Diagnosis Procedure 1.CHECK CONTINUITY RGB (R: RED) SIGNAL CIRCUIT Turn ignition switch OFF. Disconnect display unit connector M141 and AV control unit connector M154. Check continuity between display unit harness connector M141 (A) terminal 17 and AV control unit harness connector M154 (B) terminal 40 Check continuity between display unit harness connector M141 (A) terminal 17 and ground. 2.CHECK RGB (R: RED) SIGNAL Connect display unit connector M141 and AV control unit connector M154. Turn ignition switch ON. Check signal between display unit harness connector M141 terminal 17 and ground.

  • RGB (G: green) signal circuit
  • Description Transmit the image displayed with AV control unit with RGB signal to the display unit. Diagnosis Procedure 1.CHECK CONTINUITY RGB (G: GREEN) SIGNAL CIRCUIT Turn ignition switch OFF. Disconnect display unit connector M141 and AV control unit connector M154. Check continuity between display unit harness connector M141 (A) terminal 6 and AV control unit harness connector M154 (B) terminal 39. Check continuity between display unit harness connector M141 (A) terminal 6 and ground 2.CHECK RGB (G: GREEN) SIGNAL Connect display unit connector M141 and AV control unit connector M154. Turn ignition switch ON. Check signal between display unit harness connector M141 terminal 6 and ground.

  • RGB (B: blue) signal circuit
  • Description Transmit the image displayed with AV control unit with RGB signal to the display unit. Diagnosis Procedure 1.CHECK CONTINUITY RGB (B: BLUE) SIGNAL CIRCUIT Turn ignition switch OFF. Disconnect display unit connector M141 and AV control unit connector M154. Check continuity between display unit harness connector M141 (A) terminal 18 and AV control unit harness connector M154 (B) terminal 38. Check continuity between display unit harness connector M141 (A) terminal 18 and ground. 2.CHECK RGB (B: BLUE) SIGNAL Connect display unit connector M141 and AV control unit connector M154. Turn ignition switch ON. Check signal between display unit harness connector M141 terminal 18 and ground.

  • RGB synchronizing signal circuit
  • Description Transmit the RGB synchronizing signal to the display unit so as to synchronize the RGB image displayed with AV control unit. Diagnosis Procedure 1.CHECK CONTINUITY RGB SYNCHRONIZING SIGNAL CIRCUIT Turn ignition switch OFF. Disconnect display unit connector M141 and AV control unit connector M154. Check continuity between display unit harness connector M141 (A) terminal 19 and AV control unit harness connector M154 (B) terminal 41. Check continuity between display unit harness connector M141 (A) terminal 19 and ground. 2.CHECK RGB SYNCHRONIZING SIGNAL Connect display unit connector M141 and AV control unit connector M154. Turn ignition switch ON.

  • RGB area (YS) signal circuit
  • Description Transmits the display area of RGB image displayed by AV control unit with RGB area (YS) signal to display unit. Diagnosis Procedure 1.CHECK CONTINUITY RGB AREA (YS) SIGNAL CIRCUIT Turn ignition switch OFF. Disconnect display unit connector M141 and AV control unit connector M154. Check continuity between display unit harness connector M141 (A) terminal 9 and AV control unit harness connector M154 (B) terminal 43. Check continuity between display unit harness connector M141 (A) terminal 9 and ground. 2.CHECK RGB SYNCHRONIZING SIGNAL Connect display unit connector M141 and AV control unit connector M154. Turn ignition switch ON.

  • Horizontal synchronizing (HP) signal circuit
  • Description In composite image (AUX image, camera image), transmit the vertical synchronizing (VP) signal and horizontal synchronizing (HP) signal from display unit to AV control unit so as to synchronize the RGB images displayed with AV control unit such as the image quality adjusting menu, etc. Diagnosis Procedure 1.CHECK CONTINUITY HORIZONTAL SYNCHRONIZING (HP) SIGNAL CIRCUIT Turn ignition switch OFF. Disconnect display unit connector M141 and AV control unit connector M154. Check continuity between display unit harness connector M141 (A) terminal 8 and AV control unit harness connector M154 (B) terminal 45.

  • Vertical synchronizing (VP) signal circuit
  • Description In composite image (AUX image, camera image), transmit the vertical synchronizing (VP) signal and horizontal synchronizing (HP) signal from display unit to AV control unit so as to synchronize the RGB images displayed with AV control unit, such as the image quality adjusting menu, etc. Diagnosis Procedure 1.CHECK CONTINUITY VERTICAL SYNCHRONIZING (VP) SIGNAL CIRCUIT Turn ignition switch OFF. Disconnect display unit connector M141 and AV control unit connector M154. Check continuity between display unit harness connector M141 (A) terminal 20 and AV control unit harness connector M154 (B) terminal 57.

  • Front door speaker
  • Description The AV control unit sends audio signals to the BOSE speaker amp. The BOSE speaker amp. amplifies the audio signals before sending them to the front door speakers using the audio signal circuits. Diagnosis Procedure 1.CONNECTOR CHECK Check the AV control unit, BOSE speaker amp. and speaker connectors for the following: Proper connection Damage Disconnected or loose terminals 2.HARNESS CHECK Disconnect BOSE speaker amp. connector B109 and suspect speaker connector. Check continuity between BOSE speaker amp. harness connector B109 (A) and suspect speaker harness connector (B). Check continuity between BOSE speaker amp. harness connector B109 (A) and ground. 3.

  • Tweeter
  • Description The AV control unit sends audio signals to the BOSE speaker amp. The BOSE speaker amp. amplifies the audio signals before sending them to the tweeters using the audio signal circuits. Diagnosis Procedure 1.CONNECTOR CHECK Check the AV control unit, BOSE speaker amp. and speaker connectors for the following: Proper connection Damage Disconnected or loose terminals 2.HARNESS CHECK Disconnect BOSE speaker amp. connector B110 and suspect tweeter connector. Check continuity between BOSE speaker amp. harness connector B110 (A) and suspect tweeter harness connector (B). Check continuity between BOSE speaker amp. harness connector B110 (A) and ground. 3.

  • Center speaker
  • Description The AV control unit sends audio signals to the BOSE speaker amp. The BOSE speaker amp. amplifies the audio signals before sending them to the center speaker using the audio signal circuits. Diagnosis Procedure 1.CONNECTOR CHECK Check the AV control unit, BOSE speaker amp. and speaker connectors for the following: Proper connection Damage Disconnected or loose terminals 2.HARNESS CHECK Disconnect BOSE speaker amp. connector B109 and center speaker connector M130. Check continuity between BOSE speaker amp. harness connector B109 (A) and center speaker harness connector M130 (B). Check continuity between BOSE speaker amp. harness connector B109 (A) and ground. 3.

  • Rear door speaker
  • Description The AV control unit sends audio signals to the BOSE speaker amp. The BOSE speaker amp. amplifies the audio signals before sending them to the rear door speakers using the audio signal circuits. Diagnosis Procedure 1.CONNECTOR CHECK Check the AV control unit, BOSE speaker amp. and speaker connectors for the following: Proper connection Damage Disconnected or loose terminals 2.HARNESS CHECK Disconnect BOSE speaker amp. connectors B109, B110 and suspect speaker connector. Check continuity between BOSE speaker amp. harness connectors B109 (A) and B110 (B) and suspect speaker harness connector (C). Check continuity between BOSE speaker amp.

  • Subwoofer
  • Description The AV control unit sends audio signals to the BOSE speaker amp. The BOSE speaker amp. amplifies the audio signals before sending them to the subwoofers using the audio signal circuits. Diagnosis Procedure 1.CONNECTOR CHECK Check the AV control unit, BOSE speaker amp. and subwoofer connectors for the following: Proper connection Damage Disconnected or loose terminals 2.HARNESS CHECK Disconnect BOSE speaker amp. connector B110 and suspect rear subwoofer connector. Check continuity between BOSE speaker amp. harness connector B110 (A) and suspect rear subwoofer harness connector (B). Check continuity between BOSE speaker amp. harness connector B110 (A) and ground 3.

  • AMP on signal circuit
  • Description When the audio system is turned on, a voltage signal is supplied from the AV control unit to the BOSE speaker amp. When this signal is received, the BOSE speaker amp. will turn on. Diagnosis Procedure 1.CHECK AMP ON SIGNAL (BOSE SPEAKER AMP) Turn audio system ON. Check voltage between BOSE speaker amp. harness connector B109 terminal 20 and ground. 2.CHECK AMP ON SIGNAL (AV CONTROL UNIT) Check voltage between AV control unit harness connector M157 terminal 110 and ground.

  • Steering switch
  • Description When one of the steering wheel audio control switches is pushed, the resistance in the steering wheel audio control 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 AV CONTROL UNIT Disconnect AV control unit connector M152. Check continuity between AV control unit harness connector M152 and combination switch(spiral cable) harness connector M30. Check continuity between AV control unit connector M152 and ground. 3.

  • Communication signal circuit
  • SATELLITE RADIO TUNER SATELLITE RADIO TUNER : Description Communication signals are exchanged between the AV control unit and satellite radio tuner using the communication circuits. SATELLITE RADIO TUNER : Diagnosis Procedure 1.CHECK HARNESS - 1 Turn ignition switch OFF. Disconnect satellite radio tuner (factory installed) connector B111 and AV control unit connector M153. Check continuity between satellite radio tuner (factory installed) harness connector B111 (A) terminal 28 and AV control unit harness connector M153 (B) terminal 28. Check continuity between satellite radio tuner (factory installed) harness connector B111 (A) terminal 28 and ground. 2.

  • Sound signal circuit
  • SATELLITE RADIO TUNER SATELLITE RADIO TUNER : Description Left and right channel audio signals are supplied from the satellite radio tuner to the AV control unit through the sound signal circuits. SATELLITE RADIO TUNER : Diagnosis Procedure LEFT CHANNEL 1.CHECK HARNESS Turn ignition switch OFF. Disconnect satellite radio tuner (factory installed) connector B111 and AV control unit connector M153. Check continuity between satellite radio tuner (factory installed) connector B111 (A) and AV control unit connector M153 (B). Check continuity between satellite radio tuner (factory installed) connector B111 (A) and ground. 2.

  • 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 B131 (A) and microphone harness connector R7 (B). Check continuity between Bluetooth control unit harness connector B131 (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)

U1000 CAN comm circuit