Network, generic

U0307 Software Incompatibility With Glow Plug Control Module 1

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modeNo

Glow plug control module 1 switches the glow plugs of a diesel and exchanges data with the engine controller, usually over LIN. U0307 means that the controller does not accept the module's software. Volkswagen's 2014 Touareg TDI specification book sets it when the software check carried out over the LIN message fails. Ford's diesel OBD summaries of 2015 and 2023 list U0307 among the network faults and trip it when the glow module reports that it has fallen back to a safe glow mode; Ford's 2014 code interpretation marks it as a MIL code. GM tells technicians to check and update the module software on 2017 6.6 L L5P trucks after any glow plug replacement (PIP5524). CARB requires glow plug function to be monitored. Expect hard cold starts, white smoke and a lit MIL. U0106 means lost contact, U0407 invalid data.

Likely causes

Glow plug module software outdated or not matching the engine controller
Replacement glow module of another part number or engine variant fitted
Engine controller updated or replaced without updating the glow module
Disturbed LIN line corrupting the software check

Symptoms

  • Long cranking or no start in cold weather
  • White smoke and rough idle after a cold start
  • MIL and glow plug warning lamp on

Repair estimate

DifficultyShop_onlyWorkshop job
Parts and labour€80–600
Time0.4–2 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

glow plug moduleecmcontrol module software

Related codes

U0106U0407U030BP0670

References: static.nhtsa.gov, fordservicecontent.com, fordservicecontent.com, performanceparts.ford.com.