U0039

Vehicle Communication Bus B (+) Open

Severity

⚠️ Medium

Can you drive?

Limited driving only, diagnose soon

Approx. repair cost

$6–56 (est.)

Symptoms

Check Engine Light Is On
Malfunction of related systems (for example, airbags)
Lost communication with one or more modules
Incorrect dashboard readings

Causes

Bus B wire break (+)
Poor contact in the connector
Corrosion or oxidation of contacts
Malfunction of one of the modules in the network
Wiring harness damage

How to Fix

Check the continuity of the Bus B wire (+)
Inspect and clean the contacts in the connectors
Check connections between modules
Scan all modules for errors
Repair only from an authorized dealer

Related codes

U0040 U0041 U0042