OBD Guide

P1791

Vehicle Speed Sensor Range/Performance Problem

P1791 is an OBD-II diagnostic trouble code meaning: Vehicle Speed Sensor Range/Performance Problem. Common causes: speed sensor (vss) malfunction, open or short circuit in the sensor circuit. Estimated repair cost: $6–33.

Severity
⚠️ Medium
Can you drive?
Limited driving only, diagnose soon
Approx. repair cost
$6–33 (est.)

Symptoms

  • Incorrect speedometer readings
  • Gear shifting problems
  • Cruise control not working
  • Check Engine Light Illuminates
  • Increased fuel consumption

Causes

  • Speed sensor (VSS) malfunction
  • Open or short circuit in the sensor circuit
  • Poor contact in the sensor connector
  • Damage to the sensor drive mechanism
  • Problems with the ECU

How to Fix

  1. Check the integrity of the sensor wiring and connectors
  2. Test the speed sensor with a multimeter
  3. Check the sensor drive mechanism for damage
  4. Replace faulty speed sensor
  5. If necessary, diagnose the ECU

Related codes

Error P1791 by Vehicle Brand

FAQ

What does the P1791 code mean?

P1791 is an OBD-II diagnostic trouble code that indicates: Vehicle Speed Sensor Range/Performance Problem

What causes a P1791 error code?

The most common causes of P1791 include: Speed sensor (VSS) malfunction; Open or short circuit in the sensor circuit; Poor contact in the sensor connector; Damage to the sensor drive mechanism.

How do I fix a P1791 diagnostic trouble code?

To fix P1791: Check the integrity of the sensor wiring and connectors. Test the speed sensor with a multimeter. Check the sensor drive mechanism for damage. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with P1791?

Limited driving only, diagnose soon

How much does it cost to fix P1791?

The estimated repair cost for P1791 is $6–33. Actual cost depends on your vehicle, location, and labor rates.

See also: Russian version · NationStat