OBD Guide

U0685

Lost Communication With Catalyst Temperature Bank 1 Sensor 2

U0685 is an OBD-II diagnostic trouble code meaning: Lost Communication With Catalyst Temperature Bank 1 Sensor 2. Common causes: open or short circuit in the wiring to the sensor, malfunction of the catalyst temperature sensor. 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 Is On
  • Reduced engine performance
  • Increased fuel consumption
  • Unusual sounds from the exhaust system

Causes

  • Open or short circuit in the wiring to the sensor
  • Malfunction of the catalyst temperature sensor
  • Connector problems or contact corrosion
  • Engine control module (ECU) malfunction

How to Fix

  1. Check the integrity of the sensor wiring and connectors
  2. Check the resistance of the catalyst temperature sensor
  3. Check for corrosion in connectors
  4. Scan the control unit for other errors

Related codes

Error U0685 by Vehicle Brand

FAQ

What does the U0685 code mean?

U0685 is an OBD-II diagnostic trouble code that indicates: Lost Communication With Catalyst Temperature Bank 1 Sensor 2

What causes a U0685 error code?

The most common causes of U0685 include: Open or short circuit in the wiring to the sensor; Malfunction of the catalyst temperature sensor; Connector problems or contact corrosion; Engine control module (ECU) malfunction.

How do I fix a U0685 diagnostic trouble code?

To fix U0685: Check the integrity of the sensor wiring and connectors. Check the resistance of the catalyst temperature sensor. Check for corrosion in connectors. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with U0685?

Yes, but get it checked soon

How much does it cost to fix U0685?

The estimated repair cost for U0685 is $17–56. Actual cost depends on your vehicle, location, and labor rates.

See also: Russian version · NationStat