OBD Guide

U0631

Lost Communication With Engine Coolant Temperature Sensor 5

U0631 is an OBD-II diagnostic trouble code meaning: Lost Communication With Engine Coolant Temperature Sensor 5. Common causes: open or short circuit in the sensor circuit, coolant temperature sensor 5 malfunction. Estimated repair cost: $6–33.

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

Symptoms

  • Check Engine Light Is On
  • Increased fuel consumption
  • Deterioration of vehicle dynamics
  • Engine overheating
  • Incorrect temperature readings on the dashboard

Causes

  • Open or short circuit in the sensor circuit
  • Coolant temperature sensor 5 malfunction
  • Poor contact in the sensor connector
  • Wiring harness damage
  • ECU malfunction

How to Fix

  1. Check the integrity of the sensor circuit
  2. Check the resistance of the temperature sensor
  3. Inspect the sensor connector for oxidation or damage.
  4. Check wiring harness for damage
  5. If necessary, replace coolant temperature sensor 5

Related codes

Error U0631 by Vehicle Brand

FAQ

What does the U0631 code mean?

U0631 is an OBD-II diagnostic trouble code that indicates: Lost Communication With Engine Coolant Temperature Sensor 5

What causes a U0631 error code?

The most common causes of U0631 include: Open or short circuit in the sensor circuit; Coolant temperature sensor 5 malfunction; Poor contact in the sensor connector; Wiring harness damage.

How do I fix a U0631 diagnostic trouble code?

To fix U0631: Check the integrity of the sensor circuit. Check the resistance of the temperature sensor. Inspect the sensor connector for oxidation or damage.. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with U0631?

Limited driving only, diagnose soon

How much does it cost to fix U0631?

The estimated repair cost for U0631 is $6–33. Actual cost depends on your vehicle, location, and labor rates.

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