This bulletin applies to 2014 and later Subaru Forester models. A revised adjustment procedure is to be used when diagnosing brake light switch (BLS) related DTCs C1531 and/or C0054. If the BLS is out of adjustment, the ABS and/or VDC warning lamp may illuminate.
Before proceeding with the BLS adjustment procedure, review the related diagnostic procedure in the applicable service manual for the DTC stored in memory.
1. Before removing or adjusting the BLS, place a reference mark on the threaded/notched portion of the adjuster.
2. Measure the brake pedal stroke by first measuring the distance between the floor mat and the pedal. Then depress the brake pedal slowly until the brake lights come on and record the second measurement. Subtract the depressed pedal distance from the first (relaxed) position to obtain the pedal stroke measurement. The specification for pedal stroke to activate the BLS is 5.5 mm, +/- 2.5 mm (greater than 3 mm but less than 8 mm). If the switch activation measurement is out of specification, the BLS will need to be adjusted. When the brake lights come on too soon (not enough pedal stroke), the BLS needs to be adjusted inward toward the bulkhead. If pedal stroke is excessive before the brake lights come on, the BLS needs to be adjusted outward toward the steering wheel. The BLS is very sensitive. Moving it just one notch should bring the operation into specification, since one notch is equal to about 4 mm of movement.
3. If it is determined that the BLS needs adjustment, rotate the switch approximately 45 degrees to the left (counter-clockwise) to release it from the brake pedal bracket. Move the BLS inward or outward as required using your reference mark as a guide, then rotate the BLS to the right (clockwise) to lock it back into position. Re-measure the pedal stroke and repeat if necessary.
4. Clear the ABS/VDC system memory and road test the vehicle to confirm that no DTCs reset.
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