B0403

E/G Request NG

Severity

⚠️ Medium

Can you drive?

Do not drive — repair immediately

Symptoms

Airbag light is on
Belt pretensioners may not work
Reduced effectiveness of the passive safety system

Causes

Open or short circuit in the CAN bus
Corrosion of connectors
Engine ECU malfunction
Problems with the SDM block
Poor grounding

How to Fix

Check the integrity of the CAN bus between the engine ECU and the SDM
Inspect connectors for corrosion
Check module grounding
Read real parameters via scanner
If necessary, update the module firmware

Related codes

B0040 B0050 B0081