CAN C BUS Performance

CAN C BUS PERFORMANCE







- When Monitored:
With the ignition on.

- Set Condition:
The scan tool cannot communicate with ANY module on the CAN C Bus circuit.





1. VERIFY CAN C BUS COMMUNICATION
1. Turn the ignition on.

NOTE: Ensure the IOD fuse is installed and battery voltage is between 10.0 and 16.0 volts.

2. With the scan tool select ECU View.

NOTE: A red "X" will be next to the module that is not communicating or not installed on the vehicle, indicating that the module is not active on the Bus network. A green check indicates that the module is active on the Bus network.

Does the scan tool communicate with any module on the CAN C Bus circuit?

Yes

- The conditions that caused this symptom are not present at this time. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors.

No

- Go To 2

2. CHECK THE D65 CAN C (+) AND (D64) CAN C (-) CIRCUITS FOR A SHORT TO VOLTAGE




1. Turn the ignition on.
2. Disconnect the Gateway Module harness connector.
3. Measure the voltage of the (D65) CAN C Bus (+) circuit and the (D64) CAN C Bus (-) circuit at the Gateway Module.

Is the voltage steadily above 4.0 volts?

Yes

- Go To 3

No

- Go To 4

3. (D65) CAN C BUS (+) CIRCUIT OR (D64) CAN C BUS (-) CIRCUIT SHORTED TO VOLTAGE




1. Turn the ignition off.

NOTE: Perform the following steps for each module on the CAN C Bus Circuit.

2. Measure the voltage between the (D65) CAN C Bus (+) circuit and the (D64) CAN C Bus (-) circuit and ground at the Gateway Module.
3. Disconnect a module, turn the ignition on and check if the module that was disconnected was causing the short to voltage internally.
4. While monitoring the voltmeter, disconnect each module on the CAN C Bus Circuit one at a time.

Is there any voltage present with all modules disconnected?

Yes

- Repair the (D65) CAN C Bus (+) circuit or (D64) CAN C Bus (-) circuit for a short to voltage.
- Perform the BODY VERIFICATION TEST. Body Verification Test

No

- Replace the module that when disconnected eliminated the short to voltage.
- Perform the BODY VERIFICATION TEST. Body Verification Test

4. CHECK THE (D65) CAN C BUS (+) CIRCUIT AND THE (D64) CAN C BUS (-) CIRCUIT FOR A SHORT TO GROUND




1. Turn the ignition off.
2. Measure the resistance between the (D65) CAN C Bus (+) circuit and ground and the (D64) CAN C Bus (-) circuit and ground at the Gateway Module.

Is the resistance below 5.0 ohms on either circuit?

Yes

- Go To 5

No

- Go To 6

5. (D65) CAN C BUS (+) CIRCUIT OR (D64) CAN C (-) CIRCUIT SHORTED TO GROUND




1. Turn the ignition off.

NOTE: Perform the following steps for each module on the CAN C Bus Circuit.

2. Measure the resistance between the (D65) CAN C Bus (+) circuit and the (D64) CAN C Bus (-) circuit and ground at the Gateway Module.
3. Disconnect a module, check if the module that was disconnected was causing the short to ground internally.
4. While monitoring the ohmmeter, disconnect each module on the CAN C Bus Circuit one at a time.

Is the resistance below 5.0 ohms with all modules disconnected?

Yes

- Repair the (D65) CAN C Bus (+) circuit or (D64) CAN C Bus (-) circuit for a short to ground.
- Perform the BODY VERIFICATION TEST. Body Verification Test

No

- Replace the module that when disconnected eliminated the short to ground.
- Perform the BODY VERIFICATION TEST. Body Verification Test

6. (D65) CAN C BUS (+) CIRCUIT SHORTED TO (D64) CAN C BUS (-) CIRCUIT





NOTE: Perform the following steps for each module on the CAN C Bus Circuit.

1. Measure the resistance between the (D65) CAN C Bus (+) circuit and the (D64) CAN C Bus (-) circuit at the Gateway Module.
2. Disconnect a module, check if the module that was disconnected was causing the short internally.
3. While monitoring the ohmmeter, disconnect each module on the CAN C Bus Circuit one at a time.

Is the resistance below 5.0 ohms with all modules disconnected?

Yes

- Repair the (D65) CAN C Bus (+) circuit for a short to the (D64) CAN C Bus (-) circuit.
- Perform the BODY VERIFICATION TEST. Body Verification Test

No

- Perform the BODY VERIFICATION TEST. Body Verification Test