B2500
System
Supplemental Restraint (Airbag)
Scanner required
Full-system scanner (engine, ABS, SRS, transmission, service resets)

Occupant Sensor Disabled or Unplugged

Understand B2500, common causes, and the right TOPDON scanner to diagnose it.

SRS module detects occupant sensor disabled — often connector under passenger seat unplugged.

Common symptoms

  • Passenger airbag permanently off
  • Airbag warning

Typical causes

  • OCS connector unplugged
  • Aftermarket seat heaters installed incorrectly
  • Seat swap without sensor

What scanner do you need?

Full-system scanner (engine, ABS, SRS, transmission, service resets)

Use live data and freeze frame to confirm the fault before replacing parts. ABS, SRS, and network U-codes usually require a full-system scanner.

Diagnostic tips

  • Record freeze frame data when the code first sets
  • Clear the code only after fixing the root cause
  • Check for related pending codes that point to a common issue
  • Verify battery voltage is above 12.4V before chasing sensor codes

Recommended TOPDON scanners

Frequently asked questions

Can I diagnose B2500 with a basic code reader?
B2500 may set in the engine module, but related diagnostics often benefit from an enhanced or full-system scanner with live data and freeze frame.
Is it safe to drive with B2500?
It depends on the code and symptoms. Flashing check engine lights and misfire codes should be addressed immediately. Consult a professional if unsure.