OBD Guide

U1402

Implausible Engine Temperature Signal Received

U1402 is an OBD-II diagnostic trouble code meaning: Implausible Engine Temperature Signal Received. Common causes: coolant temperature sensor malfunction, open or short circuit in the sensor circuit. Estimated repair cost: $6–28.

Severity
⚠️ Medium
Can you drive?
Yes, but get it checked soon
Approx. repair cost
$6–28 (est.)

Symptoms

  • Unstable engine operation at idle
  • Increased fuel consumption
  • Difficulty starting the engine
  • Check Engine Light Is On
  • Reduced engine power

Causes

  • Coolant temperature sensor malfunction
  • Open or short circuit in the sensor circuit
  • Poor contact in the sensor connector
  • Software error in the engine control unit
  • Corroded contacts or damaged wiring

How to Fix

  1. Check the resistance of the temperature sensor at different temperatures
  2. Inspect the sensor wiring and connectors for damage
  3. Check the voltage in the sensor circuit
  4. If necessary, replace the coolant temperature sensor
  5. Reset the error and check if it appears again

Related codes

FAQ

What does the U1402 code mean?

U1402 is an OBD-II diagnostic trouble code that indicates: Implausible Engine Temperature Signal Received

What causes a U1402 error code?

The most common causes of U1402 include: Coolant temperature sensor malfunction; Open or short circuit in the sensor circuit; Poor contact in the sensor connector; Software error in the engine control unit.

How do I fix a U1402 diagnostic trouble code?

To fix U1402: Check the resistance of the temperature sensor at different temperatures. Inspect the sensor wiring and connectors for damage. Check the voltage in the sensor circuit. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with U1402?

Yes, but get it checked soon

How much does it cost to fix U1402?

The estimated repair cost for U1402 is $6–28. Actual cost depends on your vehicle, location, and labor rates.

See also: Russian version · NationStat