OBD-II Code
C0054
Severity
Not yet reviewed
Nobody on our side has assessed this code yet, so we are not going to guess at how serious it is.
Can you drive it
We cannot say
Treat it as unknown until a shop reads it with live data. If the check-engine light is FLASHING, stop driving as soon as it is safe to — that means an active misfire, whatever the code.
Indicative cost (USD)
$25–$250
From this code's diagnostic notes. Varies by vehicle, diagnosis, parts, and local labor. This is not a repair quote.
C0054 is a fault in the brake apply (brake pedal position) switch circuit — the EBCM/ABS module is not seeing a valid signal transition from the brake switch when the pedal is pressed, or is seeing conflicting signals between the primary stop-lamp switch and a secondary brake-position sensor.
How a shop works this
Work from evidence to part, not the other way round. A code names a circuit or a symptom; it does not name the part that failed.
Note every code that is set, not just this one.
Codes that appear together usually narrow the cause faster than any one of them read alone.
Read the freeze frame — the conditions the fault was recorded under.
Cold or warm, idle or load, road speed and engine speed. A fault that only appears cold is a different fault from one that only appears under load, even with the same code on the scanner.
Confirm the fault is current rather than history.
Clear the code and see whether it returns under those same conditions. A code that does not come back may have been logged during a repair, a flat battery, or a bad connection that has since been disturbed.
Then follow the diagnostic notes further down this page, in the order they are written.
They are written in the order a shop works this code, cheapest checks first. Where they name a component, inspect its wiring and connector before replacing it.
If the code comes back after a repair, the underlying fault is still there. That is the point to bring in a scanner with live data and freeze-frame, or a shop that has one.
Common symptoms
- Check engine light
Read the full diagnostic procedureC0054 is a fault in the brake apply (brake pedal position) switch circuit — the EBCM/ABS module is not seeing a valid signal transition from the brak…
C0054 is a fault in the brake apply (brake pedal position) switch circuit — the EBCM/ABS module is not seeing a valid signal transition from the brake switch when the pedal is pressed, or is seeing conflicting signals between the primary stop-lamp switch and a secondary brake-position sensor. Modern brake systems often use two independent contacts on a single switch (one for stop lamps, one for ABS/cruise/stability) and a fault on either contact can set this code.
Cheapest-first ladder
- Pedal-press test with a DMM at the switch connector: with pedal released the ABS/stop signal wire should read 0V (open switch); with pedal depressed it should read battery voltage (12-14V, closed). A switch that reads battery voltage at rest or zero with the pedal pressed is mechanically failed.
- Visual inspect the stop-lamp bulbs and circuit — a shorted or grounded stop-lamp bulb pulls voltage on the switch circuit and confuses the ABS module; pull the bulb and re-test.
- Pedal-bumper check — the rubber pedal-stop bumper crumbles to dust over 10+ years and lets the pedal travel a few extra millimeters at rest, which is enough to close the switch slightly and confuse the module; a $4 bumper resolves it.
- Scan-tool brake-switch state monitor during a slow pedal apply — the switch state should transition cleanly from 'released' to 'applied' within the first 1/2 inch of pedal travel; a switch that bounces between states or doesn't transition until the pedal is half-way down is misadjusted or worn. Expensive-misdiagnosis caveat: replacing the brake master cylinder or booster when the actual problem is the $20 stop-lamp switch — symptoms can overlap with low pedal feel or 'pumping up' the pedal when the real issue is the switch confusing the ABS module into an extended self-test mode.
Vehicle-specific patterns2009+ Ford F-150 throws C0054 from a known stop-lamp switch wear issue — the switch is mounted on a pedal-bracket tab and develops contact-bounce aro…
- 2009+Ford F-150 throws C0054 from a known stop-lamp switch wear issue — the switch is mounted on a pedal-bracket tab and develops contact-bounce around 80k miles; Ford issued service bulletins covering the symptom of stop lamps staying on or cruise/ABS faults setting together.
- 2007-2010Toyota Camry/Avalon/Sienna throws C0054 from a similar stop-lamp switch wear pattern that Toyota addressed in TSB territory — the symptom is intermittent stop-lamp operation plus stability-control warning lights, and the $25 switch is a 10-minute under-dash swap.
- 2004-2009Cadillac SRX/STS throws C0054 from a failed brake-pedal position sensor (separate from the stop-lamp switch) that lives on the pedal bracket.
- 2008-2013Jeep Grand Cherokee throws C0054 from corrosion at the brake-switch connector under the dash where carpet moisture wicks up the harness.
Estimated repair$25 to $250.
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