B1638

B1638-RIGHT HI BEAM 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 high beam lamp illumination. When this bus message is received, the TIPM provides a voltage output through the high beam driver circuit. The high beam driver circuit connects to the High Beam Lamp. A headlamp return signal circuit that connects to the TIPM is used. For additional information on the Headlamp operation, .

- When Monitored:
With the high beam headlamps active.

- Set Condition:
When the Totally Integrated Power Module (TIPM) detects a high condition on the (L34) Right High Beam Driver circuit.





1. INTERMITTENT CONDITION
1. Turn the ignition on.
2. With the scan tool, clear all DTCs.
3. Turn the High Beam Headlamps on.
4. With the scan tool, read DTCs.

Does the scan tool display DTC: B1638-RIGHT HI BEAM 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 (L34) RIGHT HIGH BEAM DRIVER CIRCUIT FOR A SHORT TO VOLTAGE IN THE HARNESS




1. Turn the Headlamps off.
2. Turn the ignition off.
3. Disconnect the Right Front Lamp Assembly C1 harness connector.
4. Disconnect the TIPM C3 harness connector.
5. Turn the ignition on.
6. Measure the voltage between ground and the (L34) Right High Beam Driver circuit.

Is there any voltage present?

Yes

- Repair the short to voltage in the (L34) Right High Beam 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 C3 harness connector.
3. Connect a 12-volt test light between the (L34) Right High Beam Driver circuit and (L910) Headlamp Return Signal circuit in the Right Front Lamp Assembly C1 harness connector.
4. Turn the ignition on.
5. Turn the High Beam Headlamps on.

Does the test light illuminate brightly?

Yes

- Replace the Right High Beam Bulb. .
- Perform the BODY VERIFICATION TEST. Body Verification Test.

No

- Go To 4

4. CHECK THE (L34) RIGHT HIGH BEAM DRIVER CIRCUIT FOR AN OPEN IN THE HARNESS




1. Turn the ignition off.
2. Disconnect the TIPM C3 harness connector.
3. Measure the resistance of the (L34) Right High Beam Driver circuit between the Right Front Lamp Assembly C1 harness connector and the TIPM C3 harness connector.

Is the resistance below 5.0 Ohms?

Yes

- Go To 5

No

- Repair the open in the (L34) Right High Beam Driver circuit.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

5. CHECK THE (L910) HEADLAMP RETURN SIGNAL CIRCUIT FOR AN OPEN IN THE HARNESS




1. Measure the resistance of the (L910) Headlamp Return Signal circuit between the Right Front Lamp Assembly C1 harness connector and the TIPM C3 harness connector.

Is the resistance below 5.0 Ohms?

Yes

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

No

- Repair the open in the (L910) Headlamp Return Signal circuit.
- Perform the BODY VERIFICATION TEST. Body Verification Test.