OBD Guide

P25AF

Coolant Temperature Control Module Requested MIL Illumination

P25AF is an OBD-II diagnostic trouble code meaning: Coolant Temperature Control Module Requested MIL Illumination. Common causes: coolant temperature sensor malfunction, open or short circuit in the sensor circuit. Estimated repair cost: $17–56.

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

Symptoms

  • Malfunction indicator lamp (MIL) is on
  • Unstable engine operation
  • Engine overheating
  • Reduced efficiency of the interior heating system
  • Increased fuel consumption

Causes

  • Coolant temperature sensor malfunction
  • Open or short circuit in the sensor circuit
  • Temperature control module malfunction
  • Coolant leak
  • Thermostat malfunction

How to Fix

  1. Check coolant level and leaks
  2. Check the condition and operation of the thermostat
  3. Check the coolant temperature sensor and its circuit
  4. Scan the system for additional trouble codes
  5. If necessary, replace the temperature sensor or control module

Related codes

Error P25AF by Vehicle Brand

FAQ

What does the P25AF code mean?

P25AF is an OBD-II diagnostic trouble code that indicates: Coolant Temperature Control Module Requested MIL Illumination

What causes a P25AF error code?

The most common causes of P25AF include: Coolant temperature sensor malfunction; Open or short circuit in the sensor circuit; Temperature control module malfunction; Coolant leak.

How do I fix a P25AF diagnostic trouble code?

To fix P25AF: Check coolant level and leaks. Check the condition and operation of the thermostat. Check the coolant temperature sensor and its circuit. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with P25AF?

Limited driving only, diagnose soon

How much does it cost to fix P25AF?

The estimated repair cost for P25AF is $17–56. Actual cost depends on your vehicle, location, and labor rates.

See also: Russian version · NationStat