Will set when the headlamp leveling module detects an open or short to voltage in the right headlamp leveling actuator motor 3 control circuit after 4 consecutive monitoring cycles.
Action Taken When the DTC Sets
When DTC B1459 sets, the headlamp leveling module will disable all requests to both headlamp leveling actuators.
Conditions for Clearing the DTC
- The condition responsible for setting the DTC no longer exists.
- You issue a scan tool CLEAR DTCs command.
- A history DTC will clear once 40 consecutive malfunction-free ignition cycles have occurred.
Diagnostic Aids
Thoroughly inspect the wiring and connectors. An incomplete inspection of the wiring and connectors may result in misdiagnosis causing part replacement with the reappearance of the malfunction. If an intermittent malfunction exists, refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.
| Step | Action | Yes | No |
|---|---|---|---|
| Schematic Reference: Headlight Leveling Schematics Connector End View Reference: Lighting Systems Connector End Views | |||
| 1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | Go to Diagnostic System Check - Vehicle in Vehicle DTC Information |
| 2 | Is DTC B1459 02 present? | Go to Step 3 | Go to Step 6 |
| 3 | Test the right headlamp leveling motor 3 circuit for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 13 | Go to Step 4 |
| 4 | Turn OFF the ignition. Disconnect the right headlamp leveling actuator harness connector. Connect a 3-amp fused jumper between the right headlamp leveling motor 3 circuit and the right headlamp leveling motor low reference circuit at the right headlamp leveling actuator harness connector. Turn ON the ignition, with the engine OFF. Turn ON the headlamps. With a scan tool, request the headlamp leveling module DTC display. Does the scan tool indicate DTC B1459 02 is current? | Go to Step 5 | Go to Step 9 |
| 5 | Test the right headlamp leveling motor low reference circuit for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 13 | Go to Step 10 |
| 6 | Test the right headlamp leveling motor 3 circuit for an open or short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 13 | Go to Step 7 |
| 7 | Turn OFF the ignition. Disconnect the right headlamp leveling actuator harness connector. Connect a 3-amp fused jumper between the right headlamp leveling motor 3 circuit and the right headlamp leveling motor low reference circuit at the right headlamp leveling actuator harness connector. Turn ON the ignition, with the engine OFF. Turn ON the headlamps. With a scan tool, request the headlamp leveling module DTC display. Does the scan tool indicate DTC B1459 05 is current? | Go to Step 8 | Go to Step 9 |
| 8 | Test the right headlamp leveling motor low reference circuit for an open or short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 13 | Go to Step 10 |
| 9 | Inspect for poor connections at the harness connector of the headlamp leveling control module. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 13 | Go to Step 12 |
| 10 | Inspect for poor connections at the harness connector of the right headlamp leveling actuator. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 13 | Go to Step 11 |
| 11 | Replace the right headlamp leveling actuator. Refer to Headlamp, Fog Lamp, Turn Signal Lamp, Side Marker Lamp Replacement - Front . Did you complete the replacement? | Go to Step 13 | |
| 12 | Replace the headlamp leveling control module. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming. Did you complete the replacement? | Go to Step 13 | |
| 13 | Use the scan tool in order to clear the DTCs. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting test. Does the DTC reset? | Go to Step 2 | System OK |
DTC B1459
Circuit Description
The headlamp leveling module receives inputs from the front and rear suspension position sensors to determine vehicle pitch. The suspension position sensors send an output to the headlamp leveling module as the vehicle suspension compresses and rebounds. The headlamp leveling module calculates the difference in vehicle pitch and sends a command to the headlamp leveling actuators. The headlamp leveling actuators drive the headlamps to the position commanded by the headlamp leveling module. The headlamp leveling module monitors the headlamp leveling actuator motor control circuits for proper circuit continuity and for shorts to ground or voltage. If a malfunction is detected, a DTC will be stored in memory.
DTC Descriptors
This diagnostic procedure supports the following DTC
DTC B1460 AHLD Right Servo Driver Terminal 4 Circuit
This vehicle has DTCs which include DTC Symptoms. For more information on DTC Symptoms, refer to DTC Symptom Description in Vehicle DTC Information.
| DTC Symptom | DTC Symptom Descriptor |
|---|---|
| 02 | Short to Ground |
| 05 | Short to Battery or Open |
DTC B1460
Conditions for Running the DTC
The headlamp leveling module performs this diagnostic test mode every 0.8 millisecond when the following conditions are met
- The ignition is in the ON or CRANK position.
- The headlamps are ON.