What does it mean?
B1438 is a Body (airbags, seat belts, body electronics) fault code. It indicates: Side impact sensor (LH) (squib) for power supply circuit .
Symptoms
- Airbag warning lamp illuminated with the left side restraint disabled
- Left side and curtain airbags will not deploy in a side collision
- Code returns as current after clearing, sometimes only after a road test
- Fault often appears after interior trim work or after water has entered the cabin
- No other symptom while driving, so only the lamp reveals it
Likely causes
- Chafed yellow harness in the sill or pillar area touching another circuit
- Corrosion in the sensor connector after water has run down inside the trim, one of the most frequent causes on this circuit
- Connector not fully latched or damaged during seat, sill or pillar trim removal
- Broken conductor in the supply wire between the restraint module and the sensor
- Internal short inside the side impact sensor loading its own supply
- Sensor bracket loose or its mounting surface painted, giving a poor ground reference
- Restraint control module supply output at fault
How to fix it
- Switch off the ignition, disconnect the battery and wait the specified reserve energy discharge time before opening any connector
- Remove the left sill or pillar trim and check for damp carpet, water staining and corroded terminals, curing any leak first
- Unplug the sensor and inspect both connector halves for green pins, moisture and a lock that has not clicked home
- With the sensor disconnected, check the supply wire back to the module for continuity, for a short to ground and for a short to voltage
- Confirm the sensor is bolted tightly to clean, unpainted metal at the specified torque
- Where the same part is used on both sides, swap the sensors and see whether the fault follows the unit
- Repair the wiring or fit a correct new sensor, carry out any configuration required, then clear the memory and confirm the lamp goes out