P2111

Symptoms

• Check engine light
• high or fluctuating idle (idle can climb and bounce irregularly)
• unintended acceleration/surge when the accelerator pedal is released
• rough idle
• hesitation
• stalling
• reduced power / limp mode
• high fuel consumption
• in severe cases a no-start condition.

Probable causes

• 1) Dirty or faulty throttle body — carbon/sludge or debris preventing the plate from closing fully
• or a misaligned throttle plate. 2) Defective throttle actuator control (TAC) motor — internal motor failure
• worn gears
• or electrical shorts. 3) Faulty throttle position sensor falsely reporting the throttle as open. 4) Damaged wiring or poor connections in the TAC circuit. 5) Contributing factors reported: weak battery raising throttle motor current and high underhood temperatures.

Diagnostic steps

1. Scan for codes and freeze frame data; confirm P2111 and note related throttle/TPS codes.
2. With the ignition off, visually inspect the throttle plate: it should be clean and free of debris, and should rotate slowly to wide open when pushed by hand — clean any sludge behind the plate carefully without damaging the throttle body.
3. Inspect TAC system wiring and connectors for damage, corrosion or loose pins.
4. Measure the resistance of the TAC/ETC motor with a DVOM set to ohms — sources cite approximately 2-25 ohms as typical, but check the manufacturer's spec for the vehicle; out-of-range resistance means the throttle body/actuator must be replaced.
5. Verify throttle position sensor readings track pedal input on the scan tool.
6. Clear codes, road test and confirm the throttle closes as commanded.