B1648

B1648-REAR RIGHT TURN LAMP CONTROL CIRCUIT HIGH

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

Theory of Operation

The Totally Integrated Power Module (TIPM) receives a bus message requesting turn signal lamp illumination. When this bus message is received, the TIPM provides a pulsed voltage output through the rear turn signal control circuit. The rear turn signal control circuit connects to the dual filament Park and Turn Signal Bulb in the Lamp, Tail Stop Turn. The same ground circuit is used for both the Park and Turn Signal filaments in a dual filament lamp. For additional information on the Turn Signal Lamps operation, Exterior Lamps - Operation.

- When Monitored:
With the turn signal active.

- Set Condition:
When the Totally Integrated Power Module (TIPM) detects a high condition on the (L62) Right Rear Turn Lamp Driver circuit.





1. INTERMITTENT CONDITION
1. Turn the ignition on.
2. With the scan tool, clear all DTCs.
3. Turn the Right Turn Signal on.
4. With the scan tool, read DTCs.

Does the scan tool display DTC: B1648-REAR RIGHT TURN LAMP CONTROL CIRCUIT HIGH?

Yes

- Go To 2

No

- Test complete, the condition or conditions that originally set this DTC are not present at this time. Using the wiring diagrams as a guide, check all related splices and connectors for signs of water intrusion, corrosion, pushed out or bent terminals, and correct pin tension.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

2. CHECK THE (L62) RIGHT REAR TURN LAMP DRIVER CIRCUIT FOR A SHORT TO VOLTAGE IN THE HARNESS
1. Turn the Right Turn Signal off.
2. Turn the ignition off.
3. Disconnect the Right Tail Lamp Assembly C1 harness connector.
4. Disconnect the TIPM C7 harness connector.
5. Turn the ignition on.
6. Measure the voltage between ground and the (L62) Right Rear Turn Lamp Driver circuit.

Is there any voltage present?

Yes

- Repair the short to voltage in the (L62) Right Rear Turn Lamp Driver circuit.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

No

- Go To 3

3. CHECK THE TIPM FOR CORRECT OPERATION
1. Turn the ignition off.
2. Reconnect the TIPM C7 harness connector.
3. Connect a 12-volt test light between the (L62) Right Rear Turn Lamp Driver circuit and the (Z914) Ground circuit at the Right Tail Lamp Assembly C1 harness connector.
4. Turn the ignition on.
5. Turn the Right Turn Signal on.

Does the test light blink on and off?

Yes

- Replace the Right Rear Turn Signal Bulb. .
- Perform the BODY VERIFICATION TEST. Body Verification Test.

No

- Go To 4

4. CHECK THE (L62) RIGHT REAR TURN LAMP DRIVER CIRCUIT FOR AN OPEN IN THE HARNESS
1. Turn the ignition off.
2. Disconnect the TIPM C7 harness connector.
3. Measure the resistance of the (L62) Right Rear Turn Lamp Driver circuit between the Right Tail Lamp Assembly C1 harness connector and the TIPM C7 harness connector.

Is the resistance below 5.0 Ohms?

Yes

- Go To 5

No

- Repair the open in the (L62) Right Rear Turn Lamp Driver circuit.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

5. CHECK THE (Z914) GROUND CIRCUIT FOR AN OPEN IN THE HARNESS
1. Using a 12-volt test light connected to 12-volts, check the (Z914) Ground circuit.

Does the test light illuminate brightly?

Yes

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

No

- Repair the open in the (Z914) Ground circuit.
- Perform the BODY VERIFICATION TEST. Body Verification Test.