Fault Family System: Powertrain (P-Codes) 13 SAE Codes

Glow Plug Control Module Performance

Diagnostic & Technical Explanation

Code P064C (Glow Plug Control Module 1) sets when a glow plug control module reports an internal memory/performance fault or cannot communicate over its dedicated link to the PCM, as distinct from the ECM's own external driver-circuit wiring to the module. Causes are a corrupted GPCM internal calibration, a corroded module connector, or damaged network wiring between the GPCM and PCM.

These 13 diagnostic trouble codes share one detection mechanism and one repair path, which is why MechanicDB groups them into a single authored fault family rather than repeating the same explanation 13 times.

Codes in this family (13)

Code	Definition	Repair coverage
P064C	Glow Plug Control Module 1	3 ranked fixes
P0683	Glow Plug Control Module 1 to PCM Communication Circuit	3 ranked fixes
P0684	Glow Plug Control Module 1 to PCM Communication Circuit Range/Performance	3 ranked fixes
P06DF	Glow Plug Control Module 1 Memory Checksum Error	3 ranked fixes
P06E5	Glow Plug Control Module 1 Performance	3 ranked fixes
P06F5	Glow Plug Control Module 2	3 ranked fixes
P06FA	Glow Plug Control Module 2 Performance	3 ranked fixes
P06FB	Glow Plug Control Module 2 Memory Checksum Error	3 ranked fixes
P06FC	Glow Plug Control Module 2 to PCM Communication Circuit	3 ranked fixes
P06FD	Glow Plug Control Module 2 to PCM Communication Circuit Range/Performance	3 ranked fixes
P263C	Glow Plug Control Driver Performance	3 ranked fixes
P263E	Glow Plug Control Module 1 Over Temperature	3 ranked fixes
P263F	Glow Plug Control Module 2 Over Temperature	3 ranked fixes

What this page does not show

This page publishes the fault mechanism and the code index. The licensed dataset adds, for every one of the 15,886 codes, the full authored repair set (56,729 procedures in total) with the fields deliberately withheld here:

Procedures 2..n after the first-listed procedure
Aftermarket parts cost ranges in USD (est_parts_cost_min/max_usd)
Professional labor-hour estimates (est_labor_hours)
Step-by-step diagnostic and repair instructions
Replacement-part mappings and catalog lookups
6,637 manufacturer-specific OEM codes across 32 makes ($149 tier)

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