OBD Guide

P1720

Vehicle Speed Meter Circuit Malfunction

Severity
⚠️ Medium
Can you drive?
Limited driving only, diagnose soon
Approx. repair cost
$17–56 (est.)

Symptoms

  • Speedometer doesn't work
  • Incorrect speed readings on the dashboard
  • Gear shifting problems (for automatic transmissions)
  • Cruise control not working
  • Check Engine light comes on

Causes

  • Vehicle Speed Sensor (VSS) malfunction
  • Open or short circuit in the sensor circuit
  • Poor contact in the sensor connector
  • Wiring harness fault
  • Dashboard problems

How to Fix

  1. Check the condition of the speed sensor and its connector
  2. Check the integrity of the wires in the sensor circuit
  3. Measure the speed sensor resistance
  4. Check the sensor signal using an oscilloscope
  5. If necessary, replace the speed sensor

Related codes

Error P1720 by Vehicle Brand