OBD Guide

C1291

Open Brake Lamp Switch Contacts During Deceleration

C1291 is an OBD-II diagnostic trouble code meaning: Open Brake Lamp Switch Contacts During Deceleration. Common causes: faulty brake light switch, break in the wiring harness to the switch. Estimated repair cost: $22–89.

Severity
⚠️ Medium
Can you drive?
Do not drive — repair immediately
Approx. repair cost
$22–89 (est.)

Symptoms

  • Check engine light is on
  • Cruise control doesn't work
  • Incorrect ABS/ESP operation
  • Brake lights do not turn on or are constantly on
  • The stabilization system is disabled

Causes

  • Faulty brake light switch
  • Break in the wiring harness to the switch
  • Poor electrical contact in connectors
  • Corrosion of switch contacts
  • Incorrect switch position adjustment

How to Fix

  1. Diagnosing the status of the brake light switch
  2. Checking the voltage at the switch contacts
  3. Inspect the wiring harness for damage
  4. Replacing a faulty switch if necessary
  5. Cleaning and restoring contacts in connectors
  6. Resetting the error code and checking the system operation

Related codes

FAQ

What does the C1291 code mean?

C1291 is an OBD-II diagnostic trouble code that indicates: Open Brake Lamp Switch Contacts During Deceleration

What causes a C1291 error code?

The most common causes of C1291 include: Faulty brake light switch; Break in the wiring harness to the switch; Poor electrical contact in connectors; Corrosion of switch contacts.

How do I fix a C1291 diagnostic trouble code?

To fix C1291: Diagnosing the status of the brake light switch. Checking the voltage at the switch contacts. Inspect the wiring harness for damage. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with C1291?

Do not drive — repair immediately

How much does it cost to fix C1291?

The estimated repair cost for C1291 is $22–89. Actual cost depends on your vehicle, location, and labor rates.

See also: Russian version · NationStat