System: Powertrain (P-Code)
SAE Standard (Generic)
Family: Drive Motor Excitation Current
Code P2E29: Drive Motor A Excitation Current Sensor Circuit Low Voltage
Diagnostic & Technical Explanation
Code P2E29 (Drive Motor A Excitation Current Sensor Circuit Low Voltage) 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.
First-listed procedure
Rank #1
Inspect drive motor excitation brush/slip-ring contacts
Professional Required
This is the first procedure in the authored
consideration order, not a measured cause likelihood. Execute it only when its prerequisites
and diagnostic findings support it. Its cost and labor estimates (where known), the step-by-step procedure and the
remaining 3 procedure(s) are in the licensed dataset. Ordering context.
Full family: Drive Motor Excitation Current
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)