P2128Throttle/Pedal Position Sensor/Switch E Circuit High
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- P2128 sets when pedal track E reads above its upper limit, typically from an open sensor ground, a short to 5 V or a broken track. Where E is a half-scale signal the limit lies far below the supply: GM's 2006 tables flag sensor 2 above 2.295 V and the 2014 VW Passat above 2.43 V. Pedals with two full-scale tracks use about 4.75 V (Ford, GM 2007, 19 of 39 counts) or 4.824 V for 0.2 s (GM's Bosch-based 2012 ECM). Since both tracks often share one ground, an open ground can set P2128 together with P2123. With E rejected the ECU steers on track D only and limits output; Ford's 2020-2023 summary lights MIL and wrench lamp. P2127 is the low fault on E, P2123 the high fault on D, P2138 the D/E comparison.
- What you may notice
- Engine warning lamp and reduced power message
- Weak acceleration even with the pedal fully pressed
- Often stored together with P2123 if the ground is open
- Likely causes
- LikelyOpen or high-resistance ground of the pedal sensor
- PossibleTrack E signal shorted to the 5 V reference
- PossibleBroken track or solder joint inside the pedal sensor
- 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: €20 – €350
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.