Damaged, corroded, or disconnected wiring or connector at the throttle actuator motor; Open or shorted control circuit between the throttle body and the engine control module (ECM); Failed throttle actuator motor inside the electronic throttle body; Poor electrical connection at the ECM connector; Faulty ECM driver circuit for the throttle actuator motor (less common); Blown fuse or relay supplying power to the throttle actuator circuit

DTC codes / P21xx · Fuel and air metering / P2102

P2102Throttle Actuator Control Motor Circuit Low

Q: What does code P2102 mean?

Throttle Actuator Control Motor Circuit Low. P2102 means the engine computer has detected an abnormally low voltage or current on the control circuit for the electronic throttle actuator motor, which is the motor that opens and closes the throttle plate based on driver demand. The computer expects to see a specific electrical load when it commands the motor to move, and a reading below the expected threshold triggers this code.

P2102 means the engine computer has detected an abnormally low voltage or current on the control circuit for the electronic throttle actuator motor, which is the motor that opens and closes the throttle plate based on driver demand. The computer expects to see a specific electrical load when it commands the motor to move, and a reading below the expected threshold triggers this code.

SystemPowertrain

Code typeGeneric (all makes)

SeverityHigh

Fix difficultyProfessional

AreaFuel and air metering

Symptoms you may notice

Illumination of the check engine light, often with no other noticeable symptoms
Reduced engine power or a limp-home mode with limited throttle response
The engine may idle poorly, stall, or hesitate when accelerating
The throttle pedal may feel unresponsive or require more effort to accelerate
In some vehicles, the electronic throttle control warning light or message may also appear

Common causes, most likely first

Damaged, corroded, or disconnected wiring or connector at the throttle actuator motor
Open or shorted control circuit between the throttle body and the engine control module (ECM)
Failed throttle actuator motor inside the electronic throttle body
Poor electrical connection at the ECM connector
Faulty ECM driver circuit for the throttle actuator motor (less common)
Blown fuse or relay supplying power to the throttle actuator circuit

How to diagnose and fix it

Inspect the throttle body connector and wiring for corrosion, damage, or loose pins, and repair as needed
Check the fuse and relay that supply power to the throttle actuator circuit and replace any failed components
Measure resistance and voltage on the control circuit between the throttle body and ECM, comparing to manufacturer specifications
Perform a wiggle test on the wiring harness while monitoring live data to identify intermittent faults
Clean the throttle body and perform a throttle relearn procedure if the code was set due to carbon buildup affecting motor operation
Replace the electronic throttle body if the actuator motor is confirmed faulty
If the circuit and throttle body test good, diagnose the ECM driver circuit and replace the ECM only as a last resort

What Most Techs Miss on P2102

A low circuit code often results from a poor ground connection at the throttle body or chassis, not a failed motor, so always verify ground integrity before condemning parts.
Carbon buildup on the throttle plate can increase motor load and cause the ECM to see lower-than-expected current, mimicking a circuit fault; cleaning and relearning often resolves it.
Intermittent wiring faults from chafed harnesses near the throttle body are common and may not appear during a static test, so a wiggle test with live data is essential.
Some vehicles set P2102 when the battery voltage is low or unstable, so check charging system health before diving into circuit diagnostics.
Replacing the throttle body without performing a relearn procedure can cause the new unit to set the same code immediately, leading to a misdiagnosis.

Can I keep driving with P2102?

Driving with P2102 is not recommended because the vehicle may enter limp-home mode with severely reduced power, increasing the risk of a crash. If you must move the vehicle, drive slowly and avoid highways or heavy traffic, and have it diagnosed promptly.

Tools that help

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Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.