OBD Guide

U0643

Lost Communication With Turbocharger/Supercharger A Temperature Sensor

U0643 is an OBD-II diagnostic trouble code meaning: Lost Communication With Turbocharger/Supercharger A Temperature Sensor. Common causes: open or short circuit in the sensor circuit, turbocharger temperature sensor malfunction. Estimated repair cost: $17–56.

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

Symptoms

  • Check Engine light comes on
  • Reduced engine power
  • Emergency engine operation
  • Unstable operation of the turbocharger
  • Possible turbine overheating

Causes

  • Open or short circuit in the sensor circuit
  • Turbocharger temperature sensor malfunction
  • Poor contact in connectors
  • Wiring harness damage
  • Problems with the ECU

How to Fix

  1. Check the integrity of the wiring to the sensor
  2. Check connections and connector contacts
  3. Test the temperature sensor with a multimeter
  4. Replace sensor if necessary
  5. Check the operation of the computer for errors

Related codes

Error U0643 by Vehicle Brand

FAQ

What does the U0643 code mean?

U0643 is an OBD-II diagnostic trouble code that indicates: Lost Communication With Turbocharger/Supercharger A Temperature Sensor

What causes a U0643 error code?

The most common causes of U0643 include: Open or short circuit in the sensor circuit; Turbocharger temperature sensor malfunction; Poor contact in connectors; Wiring harness damage.

How do I fix a U0643 diagnostic trouble code?

To fix U0643: Check the integrity of the wiring to the sensor. Check connections and connector contacts. Test the temperature sensor with a multimeter. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with U0643?

Limited driving only, diagnose soon

How much does it cost to fix U0643?

The estimated repair cost for U0643 is $17–56. Actual cost depends on your vehicle, location, and labor rates.

See also: Russian version · NationStat