Headlight control module: Difference between revisions
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== Overview == | == Overview == | ||
The headlight control module is part of the 1987-1988 Fiero headlight system. It controls power and direction for the [[Gen 2 headlight motors]] based on input from the headlight switch and the condition of the system. | The headlight control module is part of the 1987-1988 Fiero headlight system and is mounted behind the left front fascia near the wheel-well area. It controls power and direction for the [[Gen 2 headlight motors]] based on input from the headlight switch and the condition of the system. | ||
If the module fails, one or both headlight doors may fail to open, fail to close, move intermittently, or stop working entirely. | If the module fails, one or both headlight doors may fail to open, fail to close, move intermittently, or stop working entirely. | ||
Latest revision as of 18:12, 6 July 2026
Headlight control module refers to the electronic control module used in the Gen 2 headlight system on 1987 and 1988 Pontiac Fiero models.
The module controls operation of the pop-up headlight motors and replaces the relay-based control method used on the earlier Gen 1 headlight system.
Overview
The headlight control module is part of the 1987-1988 Fiero headlight system and is mounted behind the left front fascia near the wheel-well area. It controls power and direction for the Gen 2 headlight motors based on input from the headlight switch and the condition of the system.
If the module fails, one or both headlight doors may fail to open, fail to close, move intermittently, or stop working entirely.
Applies to
The factory headlight control module applies to:
Earlier 1984-1986 Fieros use the Gen 1 headlight system unless they have been converted to the later Gen 2 system.
System role
In the Gen 2 system, the headlight control module manages motor operation for both headlight doors.
The module receives input from the headlight switch and controls the motors to raise or lower the doors. It is also involved in stopping motor operation when the doors reach the end of travel.
Related topics:
Common symptoms
Possible symptoms of a headlight control module problem include:
- Both headlights do not open
- Both headlights do not close
- One headlight does not operate correctly
- Intermittent headlight motor operation
- Headlight motors stop unexpectedly
- Headlight motors behave differently from normal
- No motor response even though the motors are mechanically free
Diagnosis
Before replacing the headlight control module, other causes should be checked.
Basic diagnostic checks include:
- Confirm the car uses the 1987-1988 Gen 2 system.
- Check battery voltage.
- Check fuses and power supply.
- Check grounds.
- Inspect connectors and wiring.
- Check for mechanical binding in the headlight doors.
- Determine whether the fault affects one motor or both motors.
- Test the motors if possible.
- Inspect the module and connector.
Module location
The headlight control module is located behind the left front fascia, near the left front wheel well area.
It is not mounted in the front compartment itself. Access may require working from the front-left fascia/wheel-well area, depending on what is being removed or inspected.
Related topics:
Replacement
Replacement may involve disconnecting the battery, accessing the module, unplugging the connector, removing the module, installing the replacement module, and testing headlight operation.
Used original modules, repaired modules, reproduction modules, or aftermarket replacement modules may be available depending on supply.
Related topics:
- Headlight control module replacement
- Headlight motor problems
- Headlight motor repair
- Parts interchange
Gen 1 comparison
The 1984-1986 Gen 1 system does not use this module. It uses relays and earlier headlight motors instead.
Related topics:
Notes
A failed headlight control module is only one possible cause of Gen 2 headlight problems. Motor failure, worn motor bushings, bad wiring, poor grounds, connector problems, switch problems, and mechanical binding can produce similar symptoms.
Diagnosis should identify whether the fault is mechanical, electrical, motor-related, wiring-related, or module-related before replacing parts.