Communication Line Inspection

WARNING: This page is about a different car, the 2003 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 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)
  
  Fig 1: Check Continuity Between Combination Meter And Unified Meter And A/C Amp
  Courtesy of NISSAN MOTOR CO., U.S.A.
  
  Continuity should exist.
4. Check continuity between combination meter harness connector M25 terminal 18 (R/L) and ground.
  Continuity should not exist.
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.
  
  Fig 2: Checking Voltage Between Combination Meter And Ground
  Courtesy of NISSAN MOTOR CO., U.S.A.
  
  Approx. 5V
OK or NG
1. OK : GO TO 5.
2. NG : Replace the 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.
  
  Fig 3: Checking Voltage Signal With Oscilloscope
  Courtesy of NISSAN MOTOR CO., U.S.A.
  
  Fig 4: Checking Voltage Signal Between Combination Meter And Ground
  Courtesy of NISSAN MOTOR CO., U.S.A.
OK or NG
1. OK : Replace the unified meter and A/C amp. Refer to REMOVAL AND INSTALLATION OF UNIFIED METER AND .
2. NG : Replace the 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).
  
  Fig 5: Checking Continuity Between Combination Meter And Unified Meter And A/C Amp
  Courtesy of NISSAN MOTOR CO., U.S.A.
  
  Continuity should exist.
4. Check continuity between combination meter harness connector M25 terminal 19 (R/B) and ground.
  Continuity should not exist.
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/C amp. harness connector M49 terminal 9 (R/B) and ground.
  
  Fig 6: Checking Voltage Between Unified Meter And A/C Amp. And Ground
  Courtesy of NISSAN MOTOR CO., U.S.A.
  
  Approx. 5V
OK or NG
1. OK : GO TO 8.
2. NG : Replace the 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.
  
  Fig 7: Check Voltage Signal With Simple Oscilloscope
  Courtesy of NISSAN MOTOR CO., U.S.A.
  
  Fig 8: Checking voltage signal between combination meter and ground
  Courtesy of NISSAN MOTOR CO., U.S.A.
OK or NG
1. OK : Replace the combination meter.
2. NG : Replace the unified meter and A/C amp. Refer to REMOVAL AND INSTALLATION OF UNIFIED METER AND .