Fault Family System: Powertrain (P-Codes) 5 SAE Codes

Control Module System Voltage Circuit

Diagnostic & Technical Explanation

Code P052F (Glow Plug Control Module 1 System Voltage) sets when a smart control module (glow plug control module, oxygen sensor control module, or reductant/SCR control module) reports its own supply voltage is out of the expected range on its power feed. Causes are a blown fuse, a corroded power or ground connection at the module, a failing charging system, or an internal module power-supply fault.

These 5 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 5 times.

Codes in this family (5)

Code	Definition	Repair coverage
P052F	Glow Plug Control Module 1 System Voltage	4 ranked fixes
P055E	Oxygen Sensor Control Module System Voltage	4 ranked fixes
P056D	Reductant Control Module System Voltage	4 ranked fixes
P06F9	Glow Plug Control Module 2 System Voltage	4 ranked fixes
P26EB	Alternative Fuel Control Module System Voltage	4 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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