OBD2 Car ScannerWhat does B0042 mean?
B0042 stands for Third Row Left Frontal Stage 2 Deployment Control (Subfault). A body control module has found a fault in a comfort or safety system such as airbags, lights, doors, seats or climate control.
Body codes cover the airbags, seats, lights, doors and comfort systems. When the car's computer sees a reading outside its normal range, it stores this code and may turn on a warning light on the dashboard.
Common causes
- Damaged wiring or a loose connector (often under seats)
- Faulty switch, sensor or motor
- Low battery voltage
- Faulty body control module
What to do
- Read all stored and pending codes with a scanner. Several codes together often point to one cause.
- Note the freeze frame data (speed, temperature, load) recorded when the code was set.
- Inspect the wiring and connectors of the part named in the code for damage, corrosion or looseness.
- Fix the most likely and cheapest cause first, then clear the code and drive to see if it comes back.
Read this code from your own car
Plug in a cheap ELM327 adapter and the app shows every fault code, what it means and how to fix it.
Frequently asked questions
What does B0042 mean?
B0042 means “Third Row Left Frontal Stage 2 Deployment Control (Subfault)”. It belongs to the body system group: A body control module has found a fault in a comfort or safety system such as airbags, lights, doors, seats or climate control.
Is it safe to drive with B0042?
You can usually drive carefully for a short time, but fix it soon to avoid further damage or higher fuel use.
How do I clear B0042?
Fix the cause, then clear the code with an OBD2 scanner or app. If the fault is still there, the code will come back.
Related codes
- B003ASecond Row Right Frontal Stage 2 Deployment Control (Subfault)
- B003BSecond Row Right Frontal Stage 3 Deployment Control (Subfault)
- B0040Third Row Left Side Airbag Deployment Control (Subfault)
- B0041Third Row Left Frontal Stage 1 Deployment Control (Subfault)
- B0043Third Row Left Frontal Stage 3 Deployment Control (Subfault)
- B0048Third Row Right Side Airbag Deployment Control (Subfault)
- B0049Third Row Right Frontal Stage 1 Deployment Control (Subfault)
- B004AThird Row Right Frontal Stage 2 Deployment Control (Subfault)
Code meanings can vary by manufacturer. This page is general guidance, not a repair manual. Always confirm the cause before replacing parts.