U0044
Vehicle Communication Bus B (-) High
U0044 is an OBD-II diagnostic trouble code meaning: Vehicle Communication Bus B (-) High. Common causes: open or short circuit in can b circuit, poor contact in can bus connectors. Estimated repair cost: $6–56.
Symptoms
- Check Engine light comes on
- Unstable operation of the vehicle's electronic systems
- Lost connection with some modules
- Problems with diagnostics via OBD-II connector
- Incorrect dashboard readings
Causes
- Open or short circuit in CAN B circuit
- Poor contact in CAN bus connectors
- Wiring harness damage
- Fault in one of the modules connected to the bus
- Problems with power supply to CAN modules
How to Fix
- Check the integrity of the CAN B bus wiring
- Inspect and clean the contacts in the connectors
- Check voltage on CAN B bus
- Diagnose modules connected to the bus
- Replace damaged wires or connectors
Related codes
Error U0044 by Vehicle Brand
FAQ
What does the U0044 code mean?
U0044 is an OBD-II diagnostic trouble code that indicates: Vehicle Communication Bus B (-) High
What causes a U0044 error code?
The most common causes of U0044 include: Open or short circuit in CAN B circuit; Poor contact in CAN bus connectors; Wiring harness damage; Fault in one of the modules connected to the bus.
How do I fix a U0044 diagnostic trouble code?
To fix U0044: Check the integrity of the CAN B bus wiring. Inspect and clean the contacts in the connectors. Check voltage on CAN B bus. For a complete diagnosis, use an OBD-II scanner.
Is it safe to drive with U0044?
Do not drive — repair immediately
How much does it cost to fix U0044?
The estimated repair cost for U0044 is $6–56. Actual cost depends on your vehicle, location, and labor rates.
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