OBD Guide

P1C11

Vacuum Pump Relay Stuck Open

P1C11 is an OBD-II diagnostic trouble code meaning: Vacuum Pump Relay Stuck Open. Common causes: faulty vacuum pump relay, broken wiring to the relay. Estimated repair cost: $17–44.

Severity
⚠️ Medium
Can you drive?
Limited driving only, diagnose soon
Approx. repair cost
$17–44 (est.)

Symptoms

  • Stiff brake pedal
  • Reduced braking performance
  • Check engine light is on
  • Unusual noises from the vacuum pump
  • Increased fuel consumption

Causes

  • Faulty vacuum pump relay
  • Broken wiring to the relay
  • Short circuit in control circuit
  • Problems with the engine control unit
  • Mechanical jamming of the relay

How to Fix

  1. Check the condition of the vacuum pump relay
  2. Test the relay control circuit for opens and short circuits
  3. Check the voltage at the relay terminals
  4. Replace faulty relay
  5. Check the operation of the vacuum pump after replacement

Related codes

FAQ

What does the P1C11 code mean?

P1C11 is an OBD-II diagnostic trouble code that indicates: Vacuum Pump Relay Stuck Open

What causes a P1C11 error code?

The most common causes of P1C11 include: Faulty vacuum pump relay; Broken wiring to the relay; Short circuit in control circuit; Problems with the engine control unit.

How do I fix a P1C11 diagnostic trouble code?

To fix P1C11: Check the condition of the vacuum pump relay. Test the relay control circuit for opens and short circuits. Check the voltage at the relay terminals. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with P1C11?

Limited driving only, diagnose soon

How much does it cost to fix P1C11?

The estimated repair cost for P1C11 is $17–44. Actual cost depends on your vehicle, location, and labor rates.

See also: Russian version · NationStat