Powertrain, generic · Computer and auxiliary outputs

P06DF Glow Plug Control Module 1 Memory Checksum Error

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modeNo

A diesel glow plug control module has its own microcontroller. On power-up it forms a checksum over its memory and compares it with the stored value; P06DF means they differ, so the module's program or data cannot be trusted. Ford's 2023 6.7 L and 3.0 L Power Stroke list P06DF among the glow module checks, run at power-up and flagged on a RAM checksum mismatch after about 1 s. GM's L5P performs the same check on ROM (4.5 s, two trips) but reports it as P064C. CARB treats the module as a 'smart device' whose internal faults need not be pinpointed, so this is extra diagnosis by the manufacturer. The usual remedy is reprogramming or replacing the module; until then preheating may be missing.

Likely causes

Glow plug control module faulty internally (memory, controller)
Failed or interrupted programming of the module
Voltage dip or spike at power-up (weak battery, poor ground)
Moisture or corrosion in module or connector

Symptoms

  • Check engine light, possibly glow plug/wait-to-start lamp
  • Hard cold start, long cranking
  • White smoke and knocking after cold start
  • Often no symptoms when warm

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€100–700
Time0.5–2 h

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

Parts involved

glow plug control module 1module power supply

Related codes

P064CP06E5P052FP0683P06FBP263E

References: fordservicecontent.com, gsi.ext.gm.com, law.cornell.edu.