Communication Line Inspection

WARNING: This page is about a different car, the 2004 Nissan Murano. However, it is still accessible from the selected car via links, so may be relevant.

CHECK CONNECTOR
1. Turn ignition switch OFF.
2. Check combination meter, unified meter and A/C amp. and terminals (combination meter-side, unified meter and A/C amp.-side and harness-side) for looseness or bent terminals.
OK or NG
1. OK: GO TO 2.
2. NG: Repair terminal or connector.
CHECK METER/GAUGES VISUALLY
Does the pointer on the meter/gauges fluctuate at the engine start?

Is the fluctuation acceptable?
1. YES: GO TO 3.
2. NO: GO TO 6.
CHECK CONTINUITY COMMUNICATION CIRCUIT (TX: COMBINATION METER)
1. Turn ignition switch OFF.
2. Disconnect combination meter connector and unified meter and A/C amp. connector.
3. Check continuity between combination meter harness connector M25 terminal 18 (R/L) and unified meter and A/C amp. harness connector M49 terminal 19 (R/L).
  Continuity should exist.
4. Check continuity between combination meter harness connector M25 terminal 18 (R/L) and ground.
  Continuity should not exist.
  
  Fig 1: Checking Continuity Between Combination Meter Harness Connector And Ground
  Courtesy of NISSAN MOTOR CO., U.S.A.
OK or NG
1. OK: GO TO 4.
2. NG: Repair harness or connector.
CHECK VOLTAGE OF UNIFIED METER AND A/C AMP.
1. Connect unified meter and A/C amp. connector.
2. Turn ignition switch ON.
3. Check voltage between combination meter harness connector M25 terminal 18 (R/L) and ground.
  Approx. 5V
  
  Fig 2: Checking Voltage Between Combination Meter Harness Connector And Ground
  Courtesy of NISSAN MOTOR CO., U.S.A.
OK or NG
1. OK: GO TO 5.
2. NG: Replace unified meter and A/C amp. Refer to "REMOVAL AND INSTALLATION OF UNIFIED METER AND A/C AMP. ".
CHECK VOLTAGE SIGNAL OF COMBINATION METER
1. Turn ignition switch OFF and connect combination meter connector.
2. Turn ignition switch ON.
3. Check voltage signal between combination meter harness connector M25 terminal 18 (R/L) and ground with simple oscilloscope of CONSULT-II.
  18 (R/L) - Ground
  
  Fig 3: Identifying Combination Meter Connector Voltage Signal Graph
  Courtesy of NISSAN MOTOR CO., U.S.A.
  
  Fig 4: Checking Voltage Signal Between Combination Meter Harness Connector And Ground
  Courtesy of NISSAN MOTOR CO., U.S.A.
OK or NG
1. OK: Replace unified meter and A/C amp. Refer to "REMOVAL AND INSTALLATION OF UNIFIED METER AND A/C AMP. ".
2. NG: Replace combination meter.
CHECK CONTINUITY COMMUNICATION CIRCUIT (RX: COMBINATION METER)
1. Turn ignition switch OFF.
2. Disconnect combination meter connector and unified meter and A/C amp. connector.
3. Check continuity between combination meter harness connector M25 terminal 19 (R/B) and unified meter and A/C amp. harness connector M49 terminal 9 (R/B).
  Continuity should exist.
4. Check continuity between combination meter harness connector M25 terminal 19 (R/B) and ground.
  Continuity should not exist.
  
  Fig 5: Checking Continuity Between Combination Meter Harness Connector And Ground
  Courtesy of NISSAN MOTOR CO., U.S.A.
OK or NG
1. OK: GO TO 7.
2. NG: Repair harness or connector.
CHECK VOLTAGE OF COMBINATION METER
1. Connect combination meter connector.
2. Turn ignition switch ON.
3. Check voltage between unified meter and A/G amp. harness connector M49 terminal 9 (R/B) and ground.
  Approx. 5V
  
  Fig 6: Checking Voltage Between Unified Meter And A/C Amp. Harness Connector And Ground
  Courtesy of NISSAN MOTOR CO., U.S.A.
OK or NG
1. OK: GO TO 8.
2. NG: Replace combination meter.
CHECK VOLTAGE SIGNAL OF UNIFIED METER AND A/C AMP.
1. Turn ignition switch OFF and connect unified meter and A/C amp. connector.
2. Turn ignition switch ON.
3. Check voltage signal between combination meter harness connector M25 terminal 19 (R/B) and ground with simple oscilloscope of CONSULT-II.
  19 (R/B) - Ground:
  
  Fig 7: Identifying Unified Meter And A/C AMP. Voltage Signal Graph
  Courtesy of NISSAN MOTOR CO., U.S.A.
  
  Fig 8: Checking Voltage Signal Between Combination Meter Harness Connector And Ground
  Courtesy of NISSAN MOTOR CO., U.S.A.
OK or NG
1. OK: Replace combination meter.
2. NG: Replace unified meter and A/C amp. Refer to "REMOVAL AND INSTALLATION OF UNIFIED METER AND A/C AMP. ".