OBD Guide

B1291

Park Assist Sensor 4

B1291 is an OBD-II diagnostic trouble code meaning: Park Assist Sensor 4. Common causes: failure of the 4th parking sensor, broken or damaged wiring harness to the sensor. Estimated repair cost: $33–111.

Severity
⚠️ Medium
Can you drive?
Limited driving only, diagnose soon
Approx. repair cost
$33–111 (est.)

Symptoms

  • Parking assistant system does not work
  • False alarms of parking sensors
  • Parking system error message on display
  • Parking sensor horn does not work

Causes

  • Failure of the 4th parking sensor
  • Broken or damaged wiring harness to the sensor
  • Sensor contact corrosion
  • Problems with the parking system control unit
  • Mechanical damage to the sensor (shock, water ingress)

How to Fix

  1. Visual inspection of the 4th parking sensor for damage
  2. Checking the integrity of the wiring harness to the sensor
  3. Cleaning contacts and checking connections
  4. Checking the sensor resistance (comparison with working sensors)
  5. Replacing a faulty sensor if necessary
  6. Resetting the error and checking the system operation

Related codes

FAQ

What does the B1291 code mean?

B1291 is an OBD-II diagnostic trouble code that indicates: Park Assist Sensor 4

What causes a B1291 error code?

The most common causes of B1291 include: Failure of the 4th parking sensor; Broken or damaged wiring harness to the sensor; Sensor contact corrosion; Problems with the parking system control unit.

How do I fix a B1291 diagnostic trouble code?

To fix B1291: Visual inspection of the 4th parking sensor for damage. Checking the integrity of the wiring harness to the sensor. Cleaning contacts and checking connections. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with B1291?

Limited driving only, diagnose soon

How much does it cost to fix B1291?

The estimated repair cost for B1291 is $33–111. Actual cost depends on your vehicle, location, and labor rates.

See also: Russian version · NationStat