Diagnosis of DTCs C1249 – 2013-2014 Subaru BRZ

NUMBER: 06-44-12R
DATE: 10/22/12
REVISED: 04/02/14

SUBJECT: Diagnosis of DTCs C1249



This bulletin provides a diagnostic and adjustment procedure to be used when diagnosing the Brake Light Switch (BLS) which may set a DTC C1249 (BRZ) in the ABS or VDC system memory.  The Service Manual will be revised to include this procedure in the future.



NOTE: The customer should be made aware that if their driving habits include a rapid “pumping” of the brake pedal,  this action may cause these DTCs set.  This becomes more of a possibility if the stop light switch is out of adjustment.   If this driving tendency applies, these DTCs may continue to reset until the customer’s driving habits are changed.  Confirm the customer fully understands this information before proceeding further with any diagnostics.

Another possible cause is a faulty or improperly adjusted brake light switch.

IMPORTANT:  Before proceeding with the stop light switch adjustment procedure outlined below; complete the diagnostic procedure found in the applicable Service Manual for the DTC stored in memory.

stop light switch adjustment


  1. Connect the Select Monitor (SSMIII). While monitoring the Current Data Display, select the data for the stop light switch signal and master cylinder pressure.
  2. Use the following procedure WITH THE ENGINE IDLING, to check the brake light switch adjustment and master cylinder pressure:
    1. Confirm the stop light switch signal shows “OFF” with your foot off the brake pedal.
    2. Next, pump the brake pedal 5 times and after the 5th press of the pedal, release the pedal slowly and watch the value for Master Cylinder Pressure decrease.
    3. When the brake light switch status turns from “ON” to “OFF”, the master cylinder pressure should be less than 1 MPa (10 bar or 145 psi).
  3. If the pressure measured exceeds 1 MPa (10 bar or 145 psi) as indicated on the SSMIII, increase the “Gap A” dimension by .5 mm. CAREFULLY rotate the brake light switch SLOWLY, counter-clockwise approximately 1/4 turn until you feel it begin to release from the retainer.  Follow the instructions in Step 5 below to increase   “Gap A” by the required dimension.

A business card folded in half is approximately .5mm thick.

A business card folded in half is approximately .5mm thick.

.5mm thick spacer in place


  1. Reinstall the stop light switch back into the retainer but do not lock it into place.
  2. While holding the brake pedal up against the stopper and with the .5mm spacer in place, move the switch in toward the pedal until the plunger just contacts the .5mm spacer (do not depress the plunger). Turn it back to the right (clockwise) until you feel it snap back into the “locked” position.  You will need to develop a “feel” for the adjustment notches along with how the brake light switch releases and locks back into place.  This will involve some trial and error.  Once the stop light switch is locked back into position, remove the spacer.
  3. Recheck the stop light switch operation and master cylinder pressure again following the Step 3 procedure.


Remove spacer after reinstalling Stop Light Switch



For vehicles within the Basic New Car Limited Warranty period, refer to the Subaru Labor Time Guide accessible on Subarunet.



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