Fault Family System: Powertrain (P-Codes) 7 SAE Codes

HV Battery Positive Contactor

Diagnostic & Technical Explanation

Code P0AA0 sets when the battery management system commands the HV battery pack's main positive contactor open or closed and its auxiliary feedback contact does not confirm the commanded state, or the bus voltage does not rise/fall as expected within the timing window. Because this contactor carries the full pack discharge current to the drive system, the most common physical causes are contact tips welded together from repeated high-current switching or pitted from arcing, a corroded or unseated coil-driver connector, and a coil winding that has failed open. A welded-closed positive contactor is a safety-relevant fault since it can prevent the pack from fully isolating.

These 7 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 7 times.

Codes in this family (7)

Code	Definition	Repair coverage
P0AA0	Hybrid/EV Battery Positive Contactor Circuit	3 ranked fixes
P0AA1	Hybrid/EV Battery Positive Contactor Circuit Stuck Closed	3 ranked fixes
P0AA2	Hybrid/EV Battery Positive Contactor Circuit Stuck Open	3 ranked fixes
P0AD9	Hybrid/EV Battery Positive Contactor Control Circuit/Open	3 ranked fixes
P0ADA	Hybrid/EV Battery Positive Contactor Control Circuit Range/Performance	3 ranked fixes
P0ADB	Hybrid/EV Battery Positive Contactor Control Circuit Low	3 ranked fixes
P0ADC	Hybrid/EV Battery Positive Contactor Control Circuit High	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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