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U0106 Lost Communication With Glow Plug Control Module 1

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modeNo

U0106 reports that glow plug control module 1 of a diesel engine no longer communicates. In Ford's 2023 diesel summary (6.7 L and 3.0 L) the GPCM is declared lost after 5 s of silence. GM's 2015 Cruze diesel table fails it when no GPCM message arrives for 0.25 s over a 10 s test (Type B); GM's 2018 diesel table also lets the GPCM report that it misses ECM frames $C9, $4C1 or $4F1 and sets U0106 after 11 s as Type B over two trips. Isuzu's N-Series bulletin SB18-N-001A (4HK1, 2011–2018) links the MIL with U0106 to water running down the glow plug harness into the GPCM plug; sealed terminals fix it. Expect hard cold starts, white smoke and an unreliable wait-to-start lamp.

Likely causes

Water or corrosion in the glow plug module connector or harness
Module supply fuse, relay or ground faulty
Damaged CAN lines to the glow plug module
Glow plug module internally faulty (overtemperature, driver)

Symptoms

  • MIL on
  • Long cranking or no start when cold
  • White smoke after cold start
  • Wait-to-start lamp behaves oddly

Repair estimate

DifficultyMediumDIY possible
Parts and labour€40–600
Time0.5–3 h

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

Parts involved

glow plug control modulecan bus wiring

Related codes

P0381P064CU0307U0407

References: fordservicecontent.com, gsi.ext.gm.com, gsi.ext.gm.com, static.nhtsa.gov.