OBD-II code · Powertrain (generic)

P06F9 Glow Plug Control Module 2 System Voltage

Glow Plug Control Module 2 System Voltage: the control module has detected this fault condition. This affects diesel cold-start preheating.

Is it safe to drive with P06F9?

Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.

Common causes

  • Most likelySupply voltage low

Symptoms

  • Glow plug warning light on (often orange coil symbol)
  • Hard cold start or no start in cold weather
  • White smoke from exhaust during warm-up

Repair at a glance

Difficulty
Medium
DIY friendly
Often, with basic tools
Typical labour
0.6–2 h
Emissions test
Likely to fail
Parts involved
Glow Plug Control Module 2

Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.