Fault Family System: Powertrain (P-Codes) 16 SAE Codes

Hybrid EV Control Module Comm

Diagnostic & Technical Explanation

Code P0A1A sets when the hybrid/EV powertrain control module — the module that coordinates HV contactors, inverters, and torque requests — fails an internal self-test or loses communication on its vehicle network segment. Because this module sits at the center of the hybrid/EV control network, the most common physical causes are a corroded or loose power/ground connection at the module itself, a chafed CAN bus pair or a failed terminating resistor affecting its network segment, and an internal module hardware failure. A loss-of-communication fault here often triggers a cascade of related codes from every module that depends on this one for coordination, so it should be diagnosed first when it appears alongside other hybrid/EV codes.

These 16 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 16 times.

Codes in this family (16)

Code	Definition	Repair coverage
P0A1A	Generator Control Module	3 ranked fixes
P0A1B	Drive Motor A Control Module Performance	3 ranked fixes
P0A1C	Drive Motor B Control Module Performance	3 ranked fixes
P0A1D	Hybrid/EV Powertrain Control Module A	3 ranked fixes
P0A1E	Starter/Generator Control Module	3 ranked fixes
P0A1F	Battery Energy Control Module A Performance	3 ranked fixes
P0D1F	Control Module Date/Time Synchronization Error	3 ranked fixes
P0D67	Battery Charger Control Module A Performance	3 ranked fixes
P0E43	Hybrid/EV Powertrain Control Module B	3 ranked fixes
P0E5E	Battery Charger Control Module A Processor Performance	3 ranked fixes
P0EEC	Battery Energy Control Module B Performance	3 ranked fixes
P0EEF	Drive Motor A Control Module Overtemperature	3 ranked fixes
P2C8A	Hybrid/EV Battery Interface Control Module A Performance	3 ranked fixes
P2C8B	Hybrid/EV Battery Interface Control Module B Performance	3 ranked fixes
P2D77	Battery Charger Control Module B Performance	3 ranked fixes
P2D78	Battery Charger Control Module B Processor Performance	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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