B1300
System
Body (Doors)
Scanner required
Full-system scanner (engine, ABS, SRS, transmission, service resets)

Door Ajar Indicator Circuit

Understand B1300, common causes, and the right SEAFLO pump to diagnose it.

BCM detected fault in door ajar indicator circuit — dome light and alarm may behave incorrectly.

Common symptoms

  • Dome light stays on
  • Alarm false triggers
  • Battery drain

Typical causes

  • Failed door jamb switch
  • Wiring in door harness
  • BCM input circuit fault

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

Frequently asked questions

Can I diagnose B1300 with a basic code reader?
B1300 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 B1300?
It depends on the code and symptoms. Flashing check engine lights and misfire codes should be addressed immediately. Consult a professional if unsure.