U0031

Vehicle Communication Bus A (+) Low

Severity

🔴 High

Can you drive?

Limited driving only, diagnose soon

Approx. repair cost

$6–56 (est.)

Symptoms

Incorrect operation of the dashboard
Errors in the operation of various vehicle systems
Periodic shutdown of electronic systems
The Check Engine light comes on
Problems starting the engine

Causes

Open or short circuit in the CAN bus
Oxidation of contacts in connectors
Malfunction of one of the ECUs
Problems with CAN bus power supply
Mechanical damage to wiring

How to Fix

Visual inspection of CAN bus wiring
Checking contacts in connectors
Measuring resistance and voltage on the CAN bus
Disabling modules one by one to identify the faulty one
Replacing damaged wires or connectors

Related codes

U0001 U0021 U0041