Sök
P1391
System
Powertrain (Diesel)
Scanner som krävs
Enhanced OBD2 scanner (live data graphs, freeze frame, battery voltage test)

Glow Plug Circuit Low (Cylinder 1) — Diesel

Understand P1391, common causes, and the right TOPDON scanner to diagnose it.

Glow plug circuit low on cylinder 1 — diesel cold-start aid.

Vanliga symptom

  • Hard cold start
  • White smoke on cold start
  • Check engine light

Typiska orsaker

  • Failed glow plug
  • Short in glow plug circuit
  • Glow plug module fault

Vilken scanner behöver du?

Enhanced OBD2 scanner (live data graphs, freeze frame, battery voltage test)

Använd live-data och freeze frame innan du byter delar. ABS-, SRS- och U-koder kräver oftast en fullsystems-scanner.

Diagnostiktips

  • Spara freeze frame när koden först sätts
  • Rensa koden först efter att orsaken är åtgärdad
  • Kontrollera relaterade väntande koder
  • Verifiera batterispänning över 12,4 V innan du misstänker sensorer

Rekommenderade TOPDON-scannrar

Vanliga frågor

What does P1391 mean?
P1391 indicates glow plug circuit low (cylinder 1) — diesel. Glow plug circuit low on cylinder 1 — diesel cold-start aid.
Can I diagnose P1391 with a basic code reader?
P1391 may set in the engine module, but related diagnostics often benefit from an enhanced or full-system scanner with live data and freeze frame.
Which TOPDON scanner do I need for P1391?
Enhanced OBD2 scanner (live data graphs, freeze frame, battery voltage test) See recommended tools on this page.
Is it safe to drive with P1391?
It depends on the code and symptoms. Flashing check engine lights and misfire codes should be addressed immediately. Consult a professional if unsure.