OBD Guide

U0629

Lost Communication With A/C Refrigerant Temperature Sensor B

U0629 is an OBD-II diagnostic trouble code meaning: Lost Communication With A/C Refrigerant Temperature Sensor B. Common causes: open or short circuit in the sensor circuit, oxidized or damaged connector pins. Estimated repair cost: $17–56.

Severity
⚠️ Medium
Can you drive?
Yes, but get it checked soon
Approx. repair cost
$17–56 (est.)

Symptoms

  • Air conditioning system not working
  • Increased temperature in the cabin
  • Error indication on the instrument panel
  • Unstable climate control operation

Causes

  • Open or short circuit in the sensor circuit
  • Oxidized or damaged connector pins
  • Faulty refrigerant temperature sensor B
  • Wiring Harness Problems
  • Malfunction of the climate control control unit

How to Fix

  1. Diagnose the electrical circuit of the sensor
  2. Check the condition of connectors and contacts
  3. Test coolant temperature sensor B
  4. Replace sensor if necessary
  5. Check the operation of the air conditioning system after repair

Related codes

Error U0629 by Vehicle Brand

FAQ

What does the U0629 code mean?

U0629 is an OBD-II diagnostic trouble code that indicates: Lost Communication With A/C Refrigerant Temperature Sensor B

What causes a U0629 error code?

The most common causes of U0629 include: Open or short circuit in the sensor circuit; Oxidized or damaged connector pins; Faulty refrigerant temperature sensor B; Wiring Harness Problems.

How do I fix a U0629 diagnostic trouble code?

To fix U0629: Diagnose the electrical circuit of the sensor. Check the condition of connectors and contacts. Test coolant temperature sensor B. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with U0629?

Yes, but get it checked soon

How much does it cost to fix U0629?

The estimated repair cost for U0629 is $17–56. Actual cost depends on your vehicle, location, and labor rates.

See also: Russian version · NationStat