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

Drive Motor Excitation Current

Diagnostic & Technical Explanation

Code P2E28 (Drive Motor A Excitation Current Sensor Performance) covers the excitation current supplied to a wound-rotor drive motor's field winding (as distinct from the three-phase stator current), which the inverter must regulate precisely to control motor torque. The ECM flags a performance deviation, an out-of-range voltage on the excitation sensor circuit, or excitation current too high. Causes are a degraded slip-ring/brush contact feeding the rotor, a shorted turn in the field winding, or a failed excitation current sensor.

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
P2E28	Drive Motor A Excitation Current Sensor Performance	4 ranked fixes
P2E29	Drive Motor A Excitation Current Sensor Circuit Low Voltage	4 ranked fixes
P2E2A	Drive Motor A Excitation Current Sensor Circuit High Voltage	4 ranked fixes
P2E2B	Drive Motor A Excitation Current Too High	4 ranked fixes
P2E7B	Drive Motor A Excitation Current Sensor Circuit	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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