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Component Tests and General Diagnostics




Engine

F-CAN Circuit Troubleshooting

F-CAN Circuit Troubleshooting

1. F-CAN circuit resistance check:

F-CAN circuit resistance check
-1. Turn the ignition switch to LOCK (0).

-2. Jump the SCS line with the HDS.

-3. Disconnect the following connector.





-4. Disconnect the HDS.

-5. Measure the resistance between test points 1 and 2.









Is there about 46-58 Ohms?
-YES- Go to step 10.
-NO- Go to step 2.

2. Shorted wire check (F_CAN-H line to F_CAN-L line):

Shorted wire check (F_CAN-H line to F_CAN-L line)
-1. Disconnect the following connectors.
* Gauge control module (tach) 32P connector
* VSA modulator-control unit 22P connector
* Steering angle sensor 4P connector
* EPS control unit connector A (11P)
* SRS unit connector A (39P)
* TPMS control unit 20P connector
* Audio-navigation unit connector B (20P) (with navigation)

-2. Check for continuity between test points 1 and 2.









Is there continuity?
-YES- Repair a short in the F_CAN-H wire to F_CAN-L wire between ECM/PCM terminals A3 and A4.
-NO- The F_CAN-H wire and F_CAN-L wire is not shorted. Go to step 4.

3. Open wire check (F_CAN-H line) 1:

Open wire check (F_CAN-H line) 1
-1. Check for continuity between test points 1 and 2.









Is there continuity?
-YES- The F_CAN-L wire is not open. Go to step 8.
-NO- Repair an open in the F_CAN-L wire between the ECM/PCM (A4) and the gauge control module (tach).

4. Open wire check (F_CAN-H line) 2:

Open wire check (F_CAN-H line) 2
-1. Check for continuity between test points 1 and 2.









Is there continuity?
-YES- The F_CAN-H wire is not open. Go to step 5.
-NO- Repair an open in the F_CAN-H wire between the ECM/PCM (A3) and the VSA modulator-control unit.

5. Open wire check (F_CAN-H line) 3:

Open wire check (F_CAN-H line) 3
-1. Check for continuity between test points 1 and 2.









Is there continuity?
-YES- The F_CAN-H wire is not open. Go to step 6.
-NO- Repair an open in the F_CAN-H wire between the ECM/PCM (A3) and the EPS control unit.

6. Open wire check (F_CAN-L line) 1:

Open wire check (F_CAN-L line) 1
-1. Check for continuity between test points 1 and 2.









Is there continuity?
-YES- The F_CAN-L wire is not open. Go to step 7.
-NO- Repair an open in the F_CAN-L wire between the ECM/PCM (A4) and the gauge control module (tach).

7. Open wire check (F_CAN-L line) 2:

Open wire check (F_CAN-L line) 2
-1. Check for continuity between test points 1 and 2.









Is there continuity?
-YES- The F_CAN-L wire is not open. Go to step 8.
-NO- Repair an open in the F_CAN-L wire between the ECM/PCM (A4) and the VSA modulator-control unit.

8. Open wire check (F_CAN-L line) 3:

Open wire check (F_CAN-L line) 3
-1. Check for continuity between test points 1 and 2.









Is there continuity?
-YES- The F_CAN-L wire is not open. Go to step 9.
-NO- Repair an open in the F_CAN-L wire between the ECM/PCM (A4) and the EPS control unit.

9. VSA modulator-control unit internal resistance check:

VSA modulator-control unit internal resistance check
-1. Reconnect the VSA modulator-control unit 22P connector.

-2. Measure the resistance between test points 1 and 2.









Is there about 108-132 Ohms?
-YES- The VSA modulator-control unit is OK. Go to step 10.
-NO- Substitute a known-good VSA modulator-control unit Service and Repair, then reconnect ECM/PCM connector A (49P). If the HDS identifies the vehicle, replace the original VSA modulator-control unit Service and Repair.

10. Shorted wire check (F_CAN-H line):

Shorted wire check (F_CAN-H line)
-1. Disconnect the following connectors:
* Gauge control module (tach) 32P connector
* VSA modulator-control unit 22P connector
* Steering angle sensor 4P connector
* EPS control unit connector A (11P)
* SRS unit connector A (39P)
* TPMS control unit 20P connector
* Audio-navigation unit connector B (20P) (with navigation)

-2. Check for continuity between test points 1 and 2.









Is there continuity?
-YES- Repair a short in the F_CAN-H wire between ECM/PCM (A3) and the gauge control module (tach), the VSA modulator-control unit, the steering angle sensor, the EPS control unit, the SRS unit, the TPMS control unit, the navigation unit, or the DLC.
-NO- The F_CAN-H wire is OK. Go to step 11.

11. Shorted wire check (F_CAN-L line):

Shorted wire check (F_CAN-L line)
-1. Check for continuity between test points 1 and 2.









Is there continuity?
-YES- Repair a short in the F_CAN-L wire between ECM/PCM (A4) and the gauge control module (tach), the VSA modulator-control unit, the steering angle sensor, the EPS control unit, the SRS unit, the TPMS control unit, the audio-navigation unit, or the DLC.
-NO- The F_CAN-L wire is OK. Go to step 12.

12. Gauge control module (tach) check:

Gauge control module (tach) check
-1. Reconnect all connectors.

-2. Connect the HDS to the DLC.

-3. Disconnect the following connector.





-4. Turn the ignition switch to ON (II), and read the HDS.

Does the HDS identify the vehicle?
-YES- Replace the gauge control module (tach) Gauge Control Module (Tach) Removal and Installation.
-NO- Go to step 13.

13. VSA modulator-control unit check:

VSA modulator-control unit check
-1. Turn the ignition switch to LOCK (0).

-2. Reconnect the gauge control module (tach) 32P connector.

-3. Disconnect the following connector.





-4. Turn the ignition switch to ON (II), and read the HDS.

Does the HDS identify the vehicle?
-YES- Replace the VSA modulator-control unit Service and Repair.
-NO- Go to step 14.

14. Steering angle sensor check:

Steering angle sensor check
-1. Turn the ignition switch to LOCK (0).

-2. Reconnect the VSA modulator-control unit 22P connector.

-3. Disconnect the following connector.





-4. Turn the ignition switch to ON (II), and read the HDS.

Does the HDS identify the vehicle?
-YES- Replace the steering angle sensor Steering Angle Sensor Removal and Installation.
-NO- Go to step 15.

15. EPS control unit check:

EPS control unit check
-1. Turn the ignition switch to LOCK (0).

-2. Reconnect the steering angle sensor 4P connector.

-3. Disconnect the following connector.





-4. Turn the ignition switch to ON (II), and read the HDS.

Does the HDS identify the vehicle?
-YES- Replace the EPS control unit Service and Repair.
-NO- Go to step 16.

16. SRS unit check:

SRS unit check
-1. Turn the ignition switch to LOCK (0).

-2. Reconnect the EPS control unit connector A (11P).

-3. Disconnect the following connector.





-4. Turn the ignition switch to ON (II), and read the HDS.

Does the HDS identify the vehicle?
-YES- Replace the SRS unit Service and Repair.
-NO- With navigation: Go to step 17.
-NO- Without navigation: Go to step 18.

17. Audio-navigation unit check:

Audio-navigation unit check
-1. Turn the ignition switch to LOCK (0).

-2. Reconnect the SRS unit connector A (39P).

-3. Disconnect the following connector.





-4. Turn the ignition switch to ON (II), and read the HDS.

Does the HDS identify the vehicle?
-YES- Replace the audio-navigation unit Audio-Navigation Unit Removal and Installation.
-NO- Go to step 18.

18. TPMS control unit check:

TPMS control unit check
-1. Turn the ignition switch to LOCK (0).

-2. Reconnect the audio-navigation unit connector B (20P).

-3. Disconnect the following connector.





-4. Turn the ignition switch to ON (II), and read the HDS.

Does the HDS identify the vehicle?
-YES- Replace the TPMS control unit Service and Repair.
-NO- Update the ECM/PCM ECM/PCM Update if it does not have the latest software, or substitute a known-good ECM/PCM Service and Repair, then recheck. If the HDS identifies the vehicle and the ECM/PCM was updated, troubleshooting is complete. If the HDS identifies the vehicle and the ECM/PCM was substituted, replace the original ECM/PCM Service and Repair.
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