B1644

B1644-REAR LEFT TURN CONTROL CIRCUIT HIGH







- When Monitored:
Continuously

- Set Condition:
When the Front Control Module (FCM) detects a short to voltage or an 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 OK?

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 FOR A SHORT TO VOLTAGE




1. Turn the Left Turn Signal off.
2. Disconnect the Left Tail Stop/Turn Lamp harness connector.
3. Turn the ignition on.
4. Measure the voltage between ground and the (L63) Left Rear Turn Signal Control circuit.

Is there any voltage present?

Yes

- Go To 4

No

- Go To 6

4. CHECK THE (L63) LEFT REAR TURN SIGNAL CONTROL CIRCUIT FOR A SHORT TO VOLTAGE IN THE HARNESS




1. Turn the ignition off.
2. Disconnect the IPM C2 harness connector.
3. Turn the ignition on.
4. Measure the voltage between ground and the (L63) Left Rear Turn Signal Control circuit.

Is there any voltage present?

Yes

- Repair the short to voltage in the (L63) Left Rear Turn Signal Control circuit.
- 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 BATTERY VOLTAGE




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

Is there any voltage present?

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.

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




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

Is the resistance above 5.0 Ohms?

Yes

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

No

- Go To 7

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