Powertrain, generic (extended)

P2125 Throttle/Pedal Position Sensor/Switch E Circuit

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

P2125 reports a general electrical fault in signal circuit E. GM uses it as Accelerator Pedal Position Sensor 2 Circuit: the ECM looks for a continuous or intermittent open or short in the sensor 2 circuit with a counter at 12.5 ms per count (19 of 39 counts). In GM's 2006 tables sensor 2 is valid between about 0.16 and 2.3 V. GM bulletin 14636 lists P2125 among the pedal codes caused by a broken solder joint inside the pedal (2009-2011 Impala, LaCrosse). Range/Performance is P2126, explicit low or high voltage P2127/P2128, dropouts P2129, and the D/E comparison P2138. With one pedal track lost the ECU usually limits engine power.

Likely causes

Internal fault in the pedal sensor (e.g. cracked solder joint)
Open or short in the sensor 2 wiring or 5 V reference
Loose or corroded pedal or inline connector
ECM input fault

Symptoms

  • Engine warning lamp and reduced power message
  • Delayed or limited pedal response
  • Traction control may be switched off

Repair estimate

DifficultyEasyDIY possible
Parts and labour€20–350
Time0.3–1.5 h

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

Parts involved

accelerator pedal position sensorpedal sensor wiringecm

Related codes

P2126P2127P2128P2129P2138P2120

References: gsi.ext.gm.com, gsi.ext.gm.com, static.nhtsa.gov, law.cornell.edu.