OBD Guide

C1236

Left Rear Wheel Speed Sensor Input Signal Missing

Severity
⚠️ Medium
Can you drive?
Limited driving only, diagnose soon
Approx. repair cost
$56–167 (est.)

Symptoms

  • ABS light is on
  • ABS system is inactive
  • ESP may turn off
  • Possible problems with cruise control

Causes

  • Broken or damaged wiring harness
  • Wheel speed sensor malfunction
  • Poor contact in the sensor connector
  • Damage to the gear rotor (reference wheel)
  • ABS control unit malfunction

How to Fix

  1. Check the integrity of the sensor wiring harness
  2. Check the connectors of the sensor and the ABS unit
  3. Test the wheel speed sensor (with an ohmmeter or oscilloscope)
  4. Replace the wheel speed sensor if necessary
  5. Check the condition of the reference wheel

Related codes