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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 2.
-NO- Go to step 10

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 terminals A3 and A4.
-NO- The F_CAN-H wire and F_CAN-L wire is not shorted. Go to step 3.

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-H wire not open. Go to step 4.
-NO- Repair an open in the F_CAN-H wire between the ECM (A3) 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 (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 (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 (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 (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 (A4) and the EPS control unit.

9. VSA unit internal resistance check:

VSA unit internal resistance check
-1. Reconnect 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 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 (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 (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 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).

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 servo unit 25P 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 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.
-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.
-NO- Update the ECM/PCM ECM/PCM Update if it does not have the latest software, or substitute a known-good ECM Service and Repair, then recheck. If the HDS identifies the vehicle and the ECM was updated, troubleshooting is complete. If the HDS identifies the vehicle and the ECM was substituted, replace the original ECM Service and Repair.
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