Powertrain, generic (extended)

P2102 Throttle Actuator A Control Motor Circuit Low

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

P2102 means the output stage for throttle motor A sees a voltage or current that points to a short toward ground or an overloaded driver. GM lists P2100-P2103 together in its 2018 calibration as faults that limit engine power and default the throttle authority; a Bosch-based GM ECM of 2012 assigns its output-stage checks (short circuit, overtemperature or overcurrent, open load) to this group with about 0.1 s detection. Apart from such tables, no maker publicly documents P2102 on its own; many current ECUs report the same fault under P2100 with a failure-type byte. CARB requires circuit faults of output components to be detected. The throttle drops to limp position and power is cut. The high-side counterpart is P2103.

Likely causes

Motor wire chafed through and shorted to ground
Shorted winding or jammed motor drawing excess current
Water in the throttle connector bridging terminals
Faulty throttle driver in the engine control unit

Symptoms

  • Limp mode with throttle at fixed opening
  • Engine warning lamp on
  • Pedal input largely ignored

Repair estimate

DifficultyMediumDIY possible
Parts and labour€30–600
Time0.5–2.5 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

throttle actuator motorthrottle body wiringecm

Related codes

P2100P2103P2101P2118P210C

References: gsi.ext.gm.com, gsi.ext.gm.com, law.cornell.edu.