B1634

B1634-LEFT 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 is used instead of a ground circuit. For additional information on the Headlamp operation, Exterior Lamps - Operation.

- When Monitored:
With the high beam headlamps active.

- Set Condition:
When the Totally Integrated Power Module (TIPM) detects a high condition on the (L33) Left 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: B1634-LEFT 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 (L33) LEFT 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 Left Headlamp Lamp harness connector.
4. Disconnect the TIPM C3 harness connector.
5. Turn the ignition on.
6. Measure the voltage between ground and the (L33) Left High Beam Driver circuit.

Is there any voltage present?

Yes

- Repair the short to voltage in the (L33) Left 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 (L33) Left High Beam Driver circuit and (L911) Left Headlamp Return Signal circuit in the Left Headlamp Lamp harness connector.
4. Turn the ignition on.
5. Turn the High Beam Headlamps on.

Does the test light illuminate brightly?

Yes

- Replace the Left High Beam Bulb. Front Lamp Unit Bulb - Removal
- Perform the BODY VERIFICATION TEST. Body Verification Test.

No

- Go To 4

4. CHECK THE (L33) LEFT 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 (L33) Left High Beam Driver circuit between the Left Headlamp Lamp 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 (L33) Left High Beam Driver circuit.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

5. CHECK THE (L911) LEFT HEADLAMP RETURN SIGNAL CIRCUIT FOR AN OPEN IN THE HARNESS




1. Measure the resistance of the (L911) Left Headlamp Return Signal circuit between the Left Headlamp Lamp harness connector and the TIPM C3 harness connector.

Is the resistance below 5.0 Ohms?

Yes

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

No

- Repair the open in the (L911) Left Headlamp Return Signal circuit.
- Perform the BODY VERIFICATION TEST. Body Verification Test.