Speed Sensitive Volume System Does Not Work

Does speedometer is operated normally?

YES or NO 

1. Yes : GO TO 2.
2. No : Check combination meter trouble diagnosis. Refer to INSPECTION/VEHICLE SPEED SIGNAL in "COMBINATION METERS".

1. Turn the ignition switch OFF.
2. Disconnect audio unit connector and combination meter connector.
3. Check continuity between audio unit harness connector M39 terminal 18 (W/G) and Unified meter and A/C amp. harness connector M19 terminal 19 (W/G).
   1. Continuity should exist. 
4. Check continuity between audio unit harness connector M39 terminal 18 (W/G) and ground.
   1. Continuity should exist. 

OK or NG 

1. OK : GO TO 3.
2. NG :
   • Check connector housings for disconnected or loose terminals.
   • Repair harness or connector.

Fig 1: Checking Continuity Between Audio Unit Harness Connector M39 Terminal 18 (W/G) And Unified Meter And A/C Amp. Harness Connector M19 Terminal 19 (W/G)

Courtesy of NISSAN MOTOR CO., U.S.A.

1. Connect audio unit connector.
2. Turn the ignition switch ON.
3. Check voltage between audio unit harness connector M39 terminal 18 (W/G) and ground.
   1. Approx. 3.5V or more 

OK or NG 

1. OK : GO TO 4.
2. NG : Replace audio unit.

Fig 2: Checking Voltage Between Audio Unit Harness Connector M39 Terminal 18 (W/G) And Ground

Courtesy of NISSAN MOTOR CO., U.S.A.

1. Connect combination meter connector.
2. Start engine and drive vehicle at more than 40 km/h (25MPH).
3. Check the signal between audio unit harness connector M39 terminal 18 (W/G) and ground with CONSULT-II or oscilloscope.
   1. 18 (W/G) - Ground: Refer to " TERMINALS AND REFERENCE VALUE FOR AUDIO UNIT FOR BOSE SYSTEM  ". 

OK or NG 

1. OK : Replace audio unit.
2. NG : Check combination meter system. Refer to , "DIAGNOSIS FLOW " in "COMBINATION METERS".

Fig 3: Checking Signal Between Audio Unit Harness Connector M39 Terminal 18 (W/G) And Ground With CONSULT-II Or Oscilloscope

Courtesy of NISSAN MOTOR CO., U.S.A.