B3904

Rear Compartment Occupant Sensor Signal Invalid

Severity

⚠️ Medium

Can you drive?

Limited driving only, diagnose soon

Approx. repair cost

$56–167 (est.)

Symptoms

Airbag light is on
The passive safety system may not work in an accident.
The error is stored in the memory of the control unit

Causes

Rear passenger sensor malfunction
Open or short circuit in wiring harness
Poor contact in sensor connectors
SRS control unit malfunction

How to Fix

Check the integrity of the wiring harness to the sensor
Check the contacts in the sensor and control unit connectors
Test rear passenger sensor
If necessary, replace the sensor or wiring harness
Reset the error and check the system

Related codes

B3901 B3902 B3903