P2205
System
Powertrain (Diesel Emissions)
Scanner required
Full-system scanner (engine, ABS, SRS, transmission, service resets)

NOx Sensor Heater Control Circuit Low (Bank 1 Sensor 1)

Understand P2205, common causes, and the right TOPDON scanner to diagnose it.

NOx sensor heater circuit low — sensor inactive until warmed.

Common symptoms

  • SCR inactive on cold start
  • NOx readings invalid until warm

Typical causes

  • Failed heater in NOx probe
  • Short to ground
  • Blown fuse for NOx heater

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 P2205 with a basic code reader?
P2205 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 P2205?
It depends on the code and symptoms. Flashing check engine lights and misfire codes should be addressed immediately. Consult a professional if unsure.