U0034

Vehicle Communication Bus A (-) Low

Severity

⚠️ Medium

Can you drive?

Yes, but get it checked soon

Approx. repair cost

$6–33 (est.)

Symptoms

Check Engine light comes on
Malfunction of various vehicle systems
Problems starting the engine
Unstable operation of the dashboard
Lost connection with some modules

Causes

Damage to communication bus wires
Poor contact in connectors
Short circuit in the circuit
Malfunction of one of the electronic modules
Grounding problems

How to Fix

Check the integrity of the communication bus wires
Inspect and clean connectors
Check grounding
Scan all modules for errors
Replace damaged wires or connectors

Related codes

U0033 U0035 U0036