OBD Guide

U0642

Lost Communication With EVAP System Pressure Sensor/Switch Circuit B

U0642 is an OBD-II diagnostic trouble code meaning: Lost Communication With EVAP System Pressure Sensor/Switch Circuit B. Common causes: open or short circuit in the evap pressure sensor circuit, evap pressure sensor malfunction. Estimated repair cost: $17–56.

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

Symptoms

  • Check Engine light comes on
  • Smell of gasoline in or around the car
  • Increased fuel consumption
  • Unstable engine idling
  • Errors related to the EVAP system

Causes

  • Open or short circuit in the EVAP pressure sensor circuit
  • EVAP pressure sensor malfunction
  • Poor contact in the sensor connector
  • Problems with power or circuit ground
  • Engine control unit malfunction

How to Fix

  1. Check the integrity of wires and connectors in the sensor circuit
  2. Check power and ground to EVAP pressure sensor
  3. Test EVAP pressure sensor
  4. If necessary, replace the EVAP pressure sensor
  5. Check and update engine control unit software

Related codes

Error U0642 by Vehicle Brand

FAQ

What does the U0642 code mean?

U0642 is an OBD-II diagnostic trouble code that indicates: Lost Communication With EVAP System Pressure Sensor/Switch Circuit B

What causes a U0642 error code?

The most common causes of U0642 include: Open or short circuit in the EVAP pressure sensor circuit; EVAP pressure sensor malfunction; Poor contact in the sensor connector; Problems with power or circuit ground.

How do I fix a U0642 diagnostic trouble code?

To fix U0642: Check the integrity of wires and connectors in the sensor circuit. Check power and ground to EVAP pressure sensor. Test EVAP pressure sensor. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with U0642?

Yes, but get it checked soon

How much does it cost to fix U0642?

The estimated repair cost for U0642 is $17–56. Actual cost depends on your vehicle, location, and labor rates.

See also: Russian version · NationStat