P24B4
System
Powertrain (Diesel Emissions)
Scanner required
Full-system scanner (engine, ABS, SRS, transmission, service resets)

Particulate Filter Soot Accumulation High

Understand P24B4, common causes, and the right TOPDON scanner to diagnose it.

High soot load — regen required soon.

Common symptoms

  • DPF warning
  • Reduced performance approaching

Typical causes

  • Ignored moderate warning
  • Failed passive regen
  • City driving pattern

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 P24B4 with a basic code reader?
P24B4 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 P24B4?
It depends on the code and symptoms. Flashing check engine lights and misfire codes should be addressed immediately. Consult a professional if unsure.