P247B
System
Powertrain (Diesel Emissions)
Scanner required
Full-system scanner (engine, ABS, SRS, transmission, service resets)

Exhaust Gas Temperature Sensor Circuit Performance (Bank 1 Sensor 3)

Understand P247B, common causes, and the right TOPDON scanner to diagnose it.

Third EGT sensor (often post-DPF) performance fault.

Common symptoms

  • Regen monitoring fault
  • SCR efficiency codes

Typical causes

  • Failed post-DPF EGT
  • Sensor tip soot insulated
  • Wiring 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

Recommended TOPDON scanners

Frequently asked questions

Can I diagnose P247B with a basic code reader?
P247B 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 P247B?
It depends on the code and symptoms. Flashing check engine lights and misfire codes should be addressed immediately. Consult a professional if unsure.