B1644

B1644-REAR LEFT TURN CONTROL CIRCUIT HIGH





For a complete wiring diagram, refer to the Wiring Information.

- When Monitored:
Continuously

- Set Condition:
When the Front Control Module (FCM) detects a short high or open on the (L63) Left Rear Turn Signal Control circuit.





1. TEST FOR INTERMITTENT CONDITION
1. Turn the ignition on.
2. With the scan tool, erase all FCM DTCs.
3. Turn the Left Turn Signal on.
4. With the scan tool, read DTCs.

Does the scan tool display: B1644-REAR LEFT TURN CONTROL CIRCUIT HIGH?

Yes

- Go To 2

No

- The conditions that caused this code to set are not present at this time. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors.
- Perform the BODY VERIFICATION TEST. Body Verification Test

2. INSPECT LEFT REAR TURN SIGNAL BULB
1. Turn the ignition off.
2. Inspect the Left Rear Turn Signal Bulb Assembly.

Is the inoperative bulb okay?

Yes

- Go To 3

No

- Replace the Inoperative bulb.
- Perform the BODY VERIFICATION TEST. Body Verification Test

3. CHECK (L63) LEFT REAR TURN SIGNAL CONTROL CIRCUIT IN BODY HARNESS FOR A SHORT TO VOLTAGE
1. Turn the Left Turn Signal off.
2. Disconnect the Left Rear Turn Stop Tail Lamp connector.
3. Turn the ignition on.
4. Measure the voltage of the (L63) Left Rear Turn Signal Control circuit between the Left Rear Turn Stop Tail Lamp connector and ground.

Is there any voltage present?

Yes

- Repair the (L63) Left Rear Turn Signal Control circuit for a short to voltage.
- Perform the BODY VERIFICATION TEST. Body Verification Test

No

- Go To 4

4. CHECK (L63) LEFT REAR TURN SIGNAL CONTROL CIRCUIT IN BODY HARNESS FOR AN OPEN




1. Turn the ignition off.
2. Disconnect the IPM C2 connector.
3. Measure the resistance of the (L63) Left Rear Turn Signal Control circuit between the Left Rear Turn Stop Tail Lamp connector and the IPM C2 connector.

Is the resistance above 5.0 ohms?

Yes

- Repair the (L63) Left Rear Turn Signal Control circuit for an open.
- Perform the BODY VERIFICATION TEST. Body Verification Test

No

- Go To 5

5. CHECK (L63) LEFT REAR TURN SIGNAL CONTROL CIRCUIT IN IPM FOR A SHORT TO VOLTAGE




1. Disconnect the Front Control Module (FCM) from the IPM 49-way connector.
2. Turn the ignition on.
3. Measure the voltage of the (L63) Left Rear Turn Signal Control circuit between the IPM 49-way connector and ground.

Is there any voltage present?

Yes

- Replace the Integrated Power Module (IPM).
- Perform the BODY VERIFICATION TEST. Body Verification Test

No

- Go To 6

6. CHECK (L63) LEFT REAR TURN SIGNAL CONTROL CIRCUIT IN IPM FOR AN OPEN
1. Measure the resistance of the (L63) Left Rear Turn Signal Control circuit between the IPM 49-way connector and IPM C2 connector (at IPM).

Is the resistance above 5.0 ohms?

Yes

- Replace the Integrated Power Module (IPM).
- Perform the BODY VERIFICATION TEST. Body Verification Test

No

- Replace the Front Control Module (FCM).
- Perform the BODY VERIFICATION TEST. Body Verification Test