Open or broken wire in the park brake switch signal circuit, often due to corrosion or flexing at the switch connector.; Park brake switch internally stuck open or failed, preventing the circuit from grounding when the brake is released.; Corroded or loose electrical connector at the park brake switch or at the PCM.; Short to voltage on the signal circuit, which can occur if the wire rubs against a power wire.; Faulty park brake control module or electronic parking brake actuator on vehicles with electric parking brakes.; PCM internal fault, though this is rare and should only be considered after all other possibilities are ruled out.

DTC codes / P05xx · Vehicle speed, idle control and auxiliary inputs / P05E5

P05E5Park Brake Sensor/Switch Circuit High

Q: What does code P05E5 mean?

Park Brake Sensor/Switch Circuit High. P05E5 indicates that the powertrain control module (PCM) has detected an abnormally high voltage on the park brake sensor or switch circuit, which typically means the circuit is open, shorted to power, or the switch is stuck in the engaged position. The PCM expects a specific voltage range when the park brake is released and another when applied; a high reading falls outside that expected range.

P05E5 indicates that the powertrain control module (PCM) has detected an abnormally high voltage on the park brake sensor or switch circuit, which typically means the circuit is open, shorted to power, or the switch is stuck in the engaged position. The PCM expects a specific voltage range when the park brake is released and another when applied; a high reading falls outside that expected range.

SystemPowertrain

Code typeGeneric (all makes)

SeverityMedium

Fix difficultyIntermediate

AreaVehicle speed, idle control and auxiliary inputs

Symptoms you may notice

The parking brake warning light may stay illuminated constantly or fail to turn on when the brake is applied.
A message such as 'Park Brake Fault' or 'Service Parking Brake' may appear on the dashboard.
The vehicle may refuse to release the electronic parking brake or may not engage it automatically.
Cruise control or automatic hill-hold functions may be disabled as a safety precaution.
Often no symptoms besides the warning light, especially if the switch is only intermittently faulty.

Common causes, most likely first

Open or broken wire in the park brake switch signal circuit, often due to corrosion or flexing at the switch connector.
Park brake switch internally stuck open or failed, preventing the circuit from grounding when the brake is released.
Corroded or loose electrical connector at the park brake switch or at the PCM.
Short to voltage on the signal circuit, which can occur if the wire rubs against a power wire.
Faulty park brake control module or electronic parking brake actuator on vehicles with electric parking brakes.
PCM internal fault, though this is rare and should only be considered after all other possibilities are ruled out.

How to diagnose and fix it

Use a scan tool to read live data for the park brake switch status and confirm the high-voltage condition while operating the brake.
Visually inspect the park brake switch, its connector, and the wiring harness for damage, corrosion, or loose pins.
Disconnect the switch and measure resistance across its terminals in both the applied and released positions to verify it opens and closes correctly.
Check for continuity and voltage on the signal circuit between the switch and the PCM, looking for opens or unintended voltage.
If the switch tests bad, replace it and clear the code; if the circuit is faulty, repair the wiring and retest.
For electronic parking brake systems, follow the manufacturer's diagnostic procedure for the actuator and control module before replacing parts.
After repairs, clear the code and perform a road test to confirm the park brake warning light operates correctly and the code does not return.

What the park brake switch test misses

A common oversight is assuming the switch is bad when the real problem is a chafed wire that only shorts to voltage when the steering column or pedal is moved, so wiggle-test the harness while watching live data.
On vehicles with electronic parking brakes, the park brake switch signal often passes through a separate control module, and a fault there can set P05E5 even though the switch itself is fine.
The code can be set by a momentary glitch, so always check for related history codes and freeze-frame data before condemning any part.
A weak or failing battery can cause erratic voltages that mimic a switch fault, so verify battery health and charging system output before deep circuit testing.
After replacing a switch or module, some vehicles require a calibration or learn procedure for the parking brake, and skipping it can leave the code pending.

Can I keep driving with P05E5?

The vehicle is generally safe to drive because the service brake system is unaffected, but the parking brake may not engage or release properly, so avoid parking on steep inclines until repaired. If the electronic parking brake will not release, do not force the vehicle to move; have it serviced.

Tools that help

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Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.