P2176Throttle Actuator A Control System - Idle Position Not Learned
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- P2176 says the closed rest position of throttle A could not be learned. At key-on or after shutdown the controller drives the plate onto its lower stop and stores the sensor values; if they stay outside the window after the permitted attempts, the code is set. GM's 2023 table 23OBDG07 aborts the learn when the plate misses the closed target by over 1.5 % or sensor 1 lies outside 0.33-0.58 V (sensor 2: 4.42-4.67 V), within one trip; GM's hybrid tables rate it Type A. Honda bulletin 13-042 cures false P2176 on 2013 Accord, Civic and Crosstour with software, GM PIP4573B blames frozen crankcase ventilation below -23 °C, and PIP4578B carbon. A Delphi patent describes repeated learn attempts. P218A is the throttle B code.
- What you may notice
- Check engine lamp right after start
- High, surging or unstable idle
- Reduced engine power after a cold start
- Likely causes
- LikelyCarbon on plate and bore preventing a clean closed position
- PossibleIce from a frozen crankcase ventilation holding the plate open
- PossibleEngine software misjudging the sensor signals (update available)
- PossibleIdle learn not performed after cleaning or module replacement
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Easy · Often possible to do yourself.Typical cost: €0 – €400
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.