U0684
Lost Communication With Catalyst Temperature Bank 1 Sensor 1
U0684 is an OBD-II diagnostic trouble code meaning: Lost Communication With Catalyst Temperature Bank 1 Sensor 1. Common causes: open or short circuit in the sensor circuit, malfunction of the catalyst temperature sensor. Estimated repair cost: $33–89.
Symptoms
- Check Engine light comes on
- Reduced engine power
- Increased fuel consumption
- Unstable engine idling
- Increased level of harmful emissions
Causes
- Open or short circuit in the sensor circuit
- Malfunction of the catalyst temperature sensor
- Poor contact in the sensor connector
- Wiring harness damage
- Engine control unit (ECU) malfunction
How to Fix
- Check the continuity of the catalyst temperature sensor circuit
- Check sensor resistance and voltage
- Inspect the sensor connector for corrosion or damage.
- Check wiring harness for damage
- If necessary, replace the catalyst temperature sensor
Related codes
Error U0684 by Vehicle Brand
FAQ
What does the U0684 code mean?
U0684 is an OBD-II diagnostic trouble code that indicates: Lost Communication With Catalyst Temperature Bank 1 Sensor 1
What causes a U0684 error code?
The most common causes of U0684 include: Open or short circuit in the sensor circuit; Malfunction of the catalyst temperature sensor; Poor contact in the sensor connector; Wiring harness damage.
How do I fix a U0684 diagnostic trouble code?
To fix U0684: Check the continuity of the catalyst temperature sensor circuit. Check sensor resistance and voltage. Inspect the sensor connector for corrosion or damage.. For a complete diagnosis, use an OBD-II scanner.
Is it safe to drive with U0684?
Yes, but get it checked soon
How much does it cost to fix U0684?
The estimated repair cost for U0684 is $33–89. Actual cost depends on your vehicle, location, and labor rates.
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