U0074
Control Module Communication Bus B Off
U0074 is an OBD-II diagnostic trouble code meaning: Control Module Communication Bus B Off. Common causes: broken or damaged can b bus wires, short circuit in can bus. Estimated repair cost: $6–56.
Symptoms
- Some comfort systems do not work (climate control, audio system)
- Check Engine light comes on
- Errors in other systems
- Problems with central locking
- Dashboard malfunctions
Causes
- Broken or damaged CAN B bus wires
- Short circuit in CAN bus
- Fault in one of the modules connected to the bus
- Problems with module power supply
- Corrosion of connectors
How to Fix
- Check the integrity of the CAN B bus wiring
- Check connectors and contacts for corrosion
- Check the power supply of the modules connected to the bus
- Disable the modules one by one to find the faulty one.
- Check CAN bus resistance
Related codes
Error U0074 by Vehicle Brand
FAQ
What does the U0074 code mean?
U0074 is an OBD-II diagnostic trouble code that indicates: Control Module Communication Bus B Off
What causes a U0074 error code?
The most common causes of U0074 include: Broken or damaged CAN B bus wires; Short circuit in CAN bus; Fault in one of the modules connected to the bus; Problems with module power supply.
How do I fix a U0074 diagnostic trouble code?
To fix U0074: Check the integrity of the CAN B bus wiring. Check connectors and contacts for corrosion. Check the power supply of the modules connected to the bus. For a complete diagnosis, use an OBD-II scanner.
Is it safe to drive with U0074?
Yes, but get it checked soon
How much does it cost to fix U0074?
The estimated repair cost for U0074 is $6–56. Actual cost depends on your vehicle, location, and labor rates.
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