CAN Communication Circuit Check

WARNING: This page is about a different car, the 2003 Nissan Altima. However, it is still accessible from the selected car via links, so may be relevant.

CHECK CONNECTOR
1. Turn ignition switch OFF.
2. Disconnect the negative battery terminal.
3. Check following terminals and connector for damage, bent or loose connection (control module-side, meter-side and harness-side).
- ECM.
- Combination meter.
- BCM.
- IPDM E/R.
- Between ECM and IPDM E/R.
OK or NG
1. OK: GO TO 2.
2. NG: Repair terminal or connector.
CHECK HARNESS FOR SHORT CIRCUIT
1. Disconnect ECM connector and harness connector F59.
2. Check the following.
- Continuity between ECM harness connector F54 terminals 33 (L) and 34 (Y) (QR25DE models)
- Continuity between ECM harness connector F54 terminals 109 (L) and 113 (Y) (VQ35DE models).
  33 (L) 34 (Y) (QR25DE models) : Continuity should not exist.
  
  109 (L)-113 (Y) (VQ35DE models) : Continuity should not exist.
  
  Fig 1: Checking Continuity Between ECM Harness Connector F54 Terminals
  Courtesy of NISSAN MOTOR CO., U.S.A.
OK or NG
1. OK: GO TO 3.
2. NG: Repair harness between ECM and harness connector F59
CHECK HARNESS FOR SHORT CIRCUIT
1. Check the following.
- Continuity between ECM harness connector F54 terminals 33 (L), 34 (Y) and ground (QR25DE models).
- Continuity between ECM harness connector F54 terminals 109 (L), 113 (Y) and ground (VQ35DE models).
  33 (L) - ground (QR25DE models) : Continuity should not exist
  
  34 (Y) - ground (QR25DE models) : Continuity should not exist
  
  109 (L) - ground (VQ35DE models) : Continuity should not exist
  
  113 (Y) - ground (VQ35DE models) : Continuity should not exist
  
  Fig 2: Checking Continuity Between ECM Harness Connector F54 Terminals And Ground
  Courtesy of NISSAN MOTOR CO., U.S.A.
OK or NG
1. OK: GO TO 4.
2. NG: Repair harness between ECM and harness connector F59.
CHECK HARNESS FOR SHORT CIRCUIT
1. Disconnect combination meter connector, BCM connector and harness connector M7.
2. Check continuity between data link connector M22 terminals 6 (L) and 3 (Y).
  6 (L) - 3 (Y) : Continuity should not exist.
OK or NG
1. OK: GO TO 5.
2. NG:
  - Repair harness between harness connector M71 and harness connector M7.
  - Repair harness between harness connector M71 and combination meter.
  - Repair harness between harness connector M71 and data link connector.
  - Repair harness between harness connector M71 and BCM.
Fig 3: Checking Continuity Between Data Link Connector M22 Terminals 6 (L) And 3 (Y)
Courtesy of NISSAN MOTOR CO., U.S.A.
CHECK HARNESS FOR SHORT CIRCUIT
Check continuity between data link connector M22 terminals 6 (L), 3 (Y) and ground.

6 (L) - ground : Continuity should not exist.

3 (Y) - ground : Continuity should not exist.

OK or NG
1. OK: GO TO 6.
2. NG:
  - Repair harness between harness connector M71 and harness connector M7.
  - Repair harness between harness connector M71 and combination meter.
  - Repair harness between harness connector M71 and data link connector.
  - Repair harness between harness connector M71 and BCM.
Fig 4: Checking Continuity Between Data Link Connector M22 Terminals 6 (L), 3 (Y) And Ground
Courtesy of NISSAN MOTOR CO., U.S.A.
CHECK HARNESS FOR SHORT CIRCUIT
1. Disconnect harness connector E27.
2. Check continuity between harness connector E28 terminals 10 (L) and 9 (Y).
  10 (L) - 9 (Y) : Continuity should not exist.
OK or NG
1. OK: GO TO 7.
2. NG: Repair harness between harness connector E28 and harness connector E27.
Fig 5: Checking Continuity Between Harness Connector E28 Terminals 10 (L) and 9 (Y)
Courtesy of NISSAN MOTOR CO., U.S.A.
CHECK HARNESS FOR SHORT CIRCUIT
Check continuity between harness connector E28 terminals 10 (L), 9 (Y) and ground.

10 (L) - ground : Continuity should not exist.

9 (Y) - ground : Continuity should not exist.

OK or NG
1. OK: GO TO 8.
2. NG: Repair harness between harness connector E28 and harness connector E27.
Fig 6: Checking Continuity Between Harness Connector E28 Terminals 10 (L), 9 (Y) And Ground
Courtesy of NISSAN MOTOR CO., U.S.A.
CHECK HARNESS FOR SHORT CIRCUIT
1. Disconnect IPDM E/R connector.
2. Check continuity between IPDM E/R harness connector E121 terminals 48 (L) and 49 (Y).
  48 (L) - 49 (Y) : Continuity should not exist.
OK or NG
1. OK: GO TO 9.
2. NG: Repair harness between harness connector E130 and IPDM E/R.
Fig 7: Checking Continuity Between IPDM E/R Harness Connector E121 Terminals 48 (L) And 49 (Y)
Courtesy of NISSAN MOTOR CO., U.S.A.
CHECK HARNESS FOR SHORT CIRCUIT
Check continuity between IPDM E/R harness connector E121 terminals 48 (L), 49 (Y) and ground.

48 (L) - ground : Continuity should not exist.

49 (Y) - ground : Continuity should not exist.

OK or NG
1. OK: GO TO 10.
2. NG: Repair harness between harness connector E130 and IPDM E/R.
Fig 8: Checking Continuity Between IPDM E/R Harness Connector E121 Terminals 48 (L), 49 (Y) And Ground
Courtesy of NISSAN MOTOR CO., U.S.A.
ECM/IPDM E/R INTERNAL CIRCUIT INSPECTION
Perform components inspection. Refer to "ECM/IPDM E/R INTERNAL CIRCUIT INSPECTION ".

OK or NG
1. OK: Reconnect all connectors to perform "SELF-DIAG RESULTS" and "DATA MONITOR" for "ENGINE" and "BCM". Refer to CONSULT-II for "ENGINE" and CONSULT-II for "BCM".
2. NG: Replace ECM and/or IPDM E/R. Refer to "REMOVAL AND INSTALLATION OF IPDM E/R ".