Headlamp Leveling Malfunction (RPO T84 or T85)
|
|
Headlamp Leveling Malfunction (RPO T84 or T85)
|
|
Diagnostic Fault Information
|
|
Circuit
|
Short to Ground
|
Open/High Resistance
|
Short to Voltage
|
Signal Performance
|
|
Headlamp Leveling Switch Ignition
|
1
|
1
|
-
|
-
|
|
Left Headlamp Leveling Ignition
|
2
|
2
|
-
|
-
|
|
Right Headlamp Leveling Ignition
|
3
|
3
|
-
|
-
|
|
Left Headlamp Leveling Control
|
2
|
2
|
2
|
-
|
|
Right Headlamp Leveling Control
|
3
|
3
|
3
|
-
|
|
Left Headlamp Ground
|
-
|
2
|
-
|
-
|
|
Right Headlamp Ground
|
-
|
3
|
-
|
-
|
|
1. All Headlamp Leveling Actuator Malfunction
2. Left Headlamp Leveling Actuator Malfunction
3. Right Headlamp Leveling Actuator Malfunction
|
|
Circuit/System Description
|
Each headlamp assembly contains a headlamp leveling motor that is controlled by the headlight switch. The headlight switch is a resistance ladder switch and wired to the headlamp leveling motors. With the ignition in ON position the headlight switch ON, the headlamp leveling motors are supplied with a specific voltage depending upon the position of the headlamp leveling switch. With the switch in the 0 position, no voltage is supplied to the headlamp leveling motors and the headlamp aiming will be at the factory specifications. Each switch selection will provide the headlamp leveling motors with incrementally increased voltage levels changing the headlamp aiming.
Schematic Reference
Headlights/Daytime Running Lights (DRL) Schematics
Connector End View Reference
Component Connector End Views
Description and Operation
Exterior Lighting Systems Description and Operation
Electrical Information Reference
|
Circuit/System Verification
|
Ignition ON, headlamps ON, observe the function of the left and right headlamps while selecting each level position on the headlamp level switch. The left and right headlamps should move as each position is selected.
|
1.
|
Ignition OFF, disconnect the harness connector at the S30 headlamp switch.
|
|
2.
|
Ignition ON, verify that a test lamp illuminates between the ignition circuit terminal 9 and ground.
|
|
3.
|
If the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance.
|
|
4.
|
Ignition OFF, connect the harness connector at the S30 headlamp switch and disconnect the inline harness connector listed below:
|
|
|
•
|
M29L headlamp leveling actuator-left inline harness connector X115
|
|
|
•
|
M29R headlamp leveling actuator-right inline harness connector X116
|
|
5.
|
Test for less than 30 Ω between the ground circuit terminal E and ground.
|
|
6.
|
If greater than the specified range, test the ground circuit for an open/high resistance.
|
|
7.
|
Ignition ON, verify that a test lamp illuminates between the ignition circuit terminal D and ground.
|
|
8.
|
If the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance.
|
|
9.
|
Connect a test lamp between the control circuit terminal F and ground.
|
|
10.
|
Ignition ON, headlamps ON, command each headlamp level function by using the headlamp leveling switch. The test lamp should illuminate and change intensity while changing between the commanded states.
|
|
11.
|
If the test lamp is always OFF, test the control circuit for a short to ground or an open. If the circuit tests normal, test or replace the S30 headlamp switch.
|
|
12.
|
If the test lamp is always ON or does not change intensity, test the control circuit for a short to voltage or for high resistance. If the circuit tests normal, test or replace the S30 headlamp switch.
|
|
13.
|
If all circuits test normal, replace the M29 headlamp leveling actuator.
|
|
1.
|
Ignition OFF, disconnect the harness connector at the S30 headlamp switch.
|
|
2.
|
With the headlamp leveling switch in position 0, test for 2.2-2.4 k Ω between the ignition terminal 9 and control terminal 10.
|
|
3.
|
If not within the specified range, replace the S30 headlamp switch.
|
|
4.
|
With the headlamp leveling switch in position 1, test for 1.9-2.1 k Ω between the ignition terminal 9 and control terminal 10.
|
|
5.
|
If not within the specified range, replace the S30 headlamp switch.
|
|
6.
|
With the headlamp leveling switch in position 2, test for 1.7-1.9 k Ω between the ignition terminal 9 and control terminal 10.
|
|
7.
|
If not within the specified range, replace the S30 headlamp switch.
|
|
8.
|
With the headlamp leveling switch in position 3, test for 1.4-1.6 kΩ between the ignition terminal 9 and control terminal 10..
|
|
9.
|
If not within the specified range, replace the S30 headlamp switch.
|
Perform the
Diagnostic Repair Verification
after completing the diagnostic procedure.
