OBD Guide
ENFRDEESPT

B2457

Auxiliary Heater Coolant Sensor Circuit Open

B2457 is an OBD-II diagnostic trouble code meaning: Auxiliary Heater Coolant Sensor Circuit Open. Common causes: broken or damaged wiring harness, temperature sensor malfunction. Estimated repair cost: $22–89.

Severity
⚠️ Medium
Can you drive?
Yes, but get it checked soon
Approx. repair cost
$22–89 (est.)

Symptoms

  • Auxiliary heater does not work
  • Incorrect coolant temperature readings
  • Error indication on the instrument panel

Causes

  • Broken or damaged wiring harness
  • Temperature sensor malfunction
  • Poor contact in the sensor connector
  • Problems with the auxiliary heater control unit

How to Fix

  1. Check the integrity of the wiring harness to the sensor
  2. Check sensor resistance at different temperatures
  3. Clean the contacts in the sensor connector
  4. If necessary, replace the sensor or repair the wiring

Related codes

B2458B2459B2460

FAQ

What does the B2457 code mean?

B2457 is an OBD-II diagnostic trouble code that indicates: Auxiliary Heater Coolant Sensor Circuit Open

What causes a B2457 error code?

The most common causes of B2457 include: Broken or damaged wiring harness; Temperature sensor malfunction; Poor contact in the sensor connector; Problems with the auxiliary heater control unit.

How do I fix a B2457 diagnostic trouble code?

To fix B2457: Check the integrity of the wiring harness to the sensor. Check sensor resistance at different temperatures. Clean the contacts in the sensor connector. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with B2457?

Yes, but get it checked soon

How much does it cost to fix B2457?

The estimated repair cost for B2457 is $22–89. Actual cost depends on your vehicle, location, and labor rates.

FRDEESPT

See also: Russian version · NationStat