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DTC codes / P08xx · Transmission / P0835

P0835Clutch Pedal Switch 'B' Circuit High

P0835 indicates that the powertrain control module (PCM) has detected a high-voltage condition on the circuit for clutch pedal switch 'B', which is typically the cruise control or starter interlock switch on the clutch pedal. The PCM expects the signal circuit to be at a specific voltage depending on pedal position, and a sustained high reading tells the module that the circuit is open, shorted to power, or the switch contacts are stuck open.

SystemPowertrain
Code typeGeneric (all makes)
SeverityMedium
Fix difficultyIntermediate
AreaTransmission

Symptoms you may notice

  • The check engine light or service engine soon light is illuminated on the dashboard.
  • The engine may not crank when the clutch pedal is pressed, because the starter interlock signal is not being recognized.
  • Cruise control may fail to engage or may disengage unexpectedly while driving.
  • The clutch pedal may feel normal, but the vehicle may not start unless the pedal is pressed very hard or pumped.
  • Often no symptoms besides the warning light, especially if the affected switch is the cruise control cancel switch.
  • In some vehicles, the engine may start without the clutch pedal being depressed, creating a safety hazard.

Common causes, most likely first

  1. A faulty clutch pedal switch 'B' that has failed internally and remains in the open position.
  2. A disconnected, loose, or corroded electrical connector at the clutch pedal switch.
  3. A broken or chafed wire in the signal circuit between the switch and the PCM, causing an open circuit.
  4. A short to battery voltage in the signal circuit, which can occur if the wire rubs against a power wire.
  5. Improper switch adjustment or a misaligned switch plunger that prevents the switch from closing when the pedal is released.
  6. A failed PCM or a software issue in the module, although this is rare and should be considered only after all other causes are ruled out.
  7. Aftermarket floor mats or debris obstructing the clutch pedal travel, preventing the switch from actuating correctly.

How to diagnose and fix it

  1. Use a scan tool to verify P0835 is current and check freeze-frame data to see the switch state when the fault was set.
  2. Visually inspect the clutch pedal switch 'B', its connector, and the wiring harness for damage, corrosion, or loose pins.
  3. Test the switch with a multimeter to confirm it opens and closes correctly as the pedal is depressed and released.
  4. Check for continuity and voltage on the signal circuit between the switch and the PCM to rule out an open or short to power.
  5. Adjust or replace the clutch pedal switch if it fails the electrical test, following the manufacturer's procedure for setting the plunger depth.
  6. Clear the diagnostic trouble codes and perform a road test to confirm the code does not return and that cruise control and starting functions work properly.
  7. If the circuit and switch test good, consult the factory service information for PCM diagnostics and consider reprogramming or replacing the module only as a last resort.

Why clutch switch B codes mislead

  • Many vehicles use two clutch pedal switches: one for starter interlock and one for cruise control or engine management, and P0835 often refers to the cruise control switch, so the car may start and drive normally while only cruise control is affected.
  • A common mistake is replacing the starter interlock switch when the code actually points to the secondary switch, so always confirm which switch 'B' refers to in the specific vehicle's service information.
  • Aftermarket floor mats or a clutch pedal stop pad that has fallen off can prevent the switch from being fully depressed, setting a high-voltage code without any electrical fault.
  • The PCM may set P0835 intermittently if the clutch pedal is ridden lightly while driving, causing the switch to flutter between states and log a high-voltage event.
  • A short to power in the signal circuit can be caused by a wire rubbing against a sharp metal edge under the dash, which is often overlooked during a visual inspection.

Can I keep driving with P0835?

The vehicle is generally safe to drive if the only symptom is the warning light and the engine starts and runs normally, but avoid relying on cruise control until the fault is repaired. If the engine will not crank or starts without the clutch pedal depressed, stop driving and have the circuit diagnosed promptly because the starter interlock safety function may be compromised.

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.

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