Communication Line Inspection

WARNING: This page is about a different car, the 2008 Nissan Maxima. However, it is still accessible from the selected car via links, so may be relevant.

CHECK CONNECTOR
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

OK: GO TO 2.

NG: Repair terminal or connector.
CHECK METER/GAUGES VISUALLY
Does the pointer on the meter/gauges fluctuate when starting the engine?

Is the fluctuation acceptable?

YES: GO TO 3.

NO: GO TO 6.
CHECK CONTINUITY OF COMMUNICATION CIRCUIT (TX: COMBINATION METER)
1. Turn ignition switch OFF.
2. Disconnect combination meter and unified meter and A/C amp. connectors.
3. Check continuity between combination meter harness connector M24 terminal 22 and unified meter and A/C amp. harness connector M49 terminal 19.
  
  Fig 1: Checking Continuity Between Combination Meter Harness Connector M24 Terminal 22 And Ground
  Courtesy of NISSAN MOTOR CO., U.S.A.
  
  Continuity should exist.
4. Check continuity between combination meter harness connector M24 terminal 22 and ground.
  Continuity should not exist.
OK or NG

OK: GO TO 4.

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 M24 terminal 22 and ground.
  Approx. 5V
  
  Fig 2: Checking Voltage Between Combination Meter Harness Connector M24 Terminal 22 And Ground
  Courtesy of NISSAN MOTOR CO., U.S.A.
OK or NG

OK: GO TO 5.

NG: Replace the unified meter and A/C amp. Refer to "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 M24 terminal 22 and ground with simple oscilloscope of CONSULT-III.
  
  Fig 3: Checking Voltage Signal Between Combination Meter Harness Connector M24 Terminal 22 And Ground
  Courtesy of NISSAN MOTOR CO., U.S.A.
  
  22 - Ground:
  
  Fig 4: Identifying Voltage Signal Graph
  Courtesy of NISSAN MOTOR CO., U.S.A.
OK or NG

OK: Replace the unified meter and A/C amp. Refer to "UNIFIED METER AND A/C AMP. ".

NG: Replace the combination meter. Refer to "COMBINATION METER ".
CHECK CONTINUITY OF COMMUNICATION CIRCUIT (RX: COMBINATION METER)
1. Turn ignition switch OFF.
2. Disconnect combination meter and unified meter and A/C amp. connectors.
3. Check continuity between combination meter harness connector M24 terminal 21 and unified meter and A/C amp. harness connector M49 terminal 9.
  Continuity should exist.
4. Check continuity between combination meter harness connector M24 terminal 21 and ground.
  Continuity should not exist.
Fig 5: Checking Continuity Between Combination Meter Harness Connector M24 Terminal 21 And Ground
Courtesy of NISSAN MOTOR CO., U.S.A.

OK or NG

OK: GO TO 7.

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 and ground.
  Approx. 5V
Fig 6: Checking Voltage Between Unified Meter And A/C Amp. Harness Connector M49 Terminal 9 And Ground
Courtesy of NISSAN MOTOR CO., U.S.A.

OK or NG

OK: GO TO 8.

NG: Replace the combination meter. Refer to "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 M24 terminal 21 and ground with simple oscilloscope of CONSULT-III.
  
  Fig 7: Checking Voltage Signal Between Combination Meter Connector M24 Terminal 21 And Ground
  Courtesy of NISSAN MOTOR CO., U.S.A.
  
  21 - Ground:
Fig 8: Identifying Voltage Signal Graph
Courtesy of NISSAN MOTOR CO., U.S.A.

OK or NG

OK: Replace the combination meter. Refer to "COMBINATION METER ".

NG: Replace the unified meter and A/C amp. Refer to "UNIFIED METER AND A/C AMP. ".