SYS.OK|MANUAL.DB● LIVE
HOMESERVICE MANUALSMERCURY2009MILAN PREMIER, 3.0 1, AWDREPAIR AND DIAGNOSIS (SINGLE PAGE)ENGINE PERFORMANCETESTING & DIAGNOSISENGINE CONTROLS - POWERTRAIN DTC CHARTS & DESCRIPTIONS (EXCEPT DIESEL & HYBRID)DTC DIAGNOSISDTC P0121: - THROTTLE/PEDAL POSITION SENSOR A CIRCUIT RANGE/PERFORMANCE
2009 Mercury Milan Premier, 3.0 1, AWD

DTC P0121: - Throttle/Pedal Position Sensor A Circuit Range/Performance

2009 Mercury Milan Premier, 3.0 1, AWDSECTION DTC P0121: - Throttle/Pedal Position Sensor A Circuit Range/Performance
DTC P0121: - THROTTLE/PEDAL POSITION SENSOR A CIRCUIT RANGE/PERFORMANCE

For Vehicles With an Idle Air Control (IAC) Valve 
Description:  The throttle position (TP) sensor circuit is monitored by the powertrain control module (PCM) for a non-closed throttle position at idle. The test fails if the key on engine running (KOER) self-test terminates upon placing the transmission gear selector in DRIVE or REVERSE or the TP closed throttle position is not achieved when closing the throttle (idle) after opening it (in PARK or NEUTRAL).
Possible Causes: 
  • Binding throttle linkage
  • Damaged throttle body
  • TP circuit open to PCM
  • Damaged TP sensor
  • SIG RTN circuit open to the TP sensor
Diagnostic Aids:  Drive the vehicle, bring it to a stop, and turn the ignition to the OFF position. Start the engine, and run the KOER self-test at idle.
For All others 
Description:  The electronic throttle control (ETC) throttle position (TP) sensor 1 circuit was flagged as a concern by the powertrain control module (PCM) indicating an out of range in either the closed or wide open throttle (WOT) modes.
Possible Causes: 
  • Obstruction in the throttle plate movement
  • Damaged throttle body
  • TP circuit open to PCM
  • Damaged TP sensor
  • SIG RTN circuit open to the TP sensor
  • Self-test operator error (foot resting on the accelerator pedal during test)
Diagnostic Aids:  This concern exhibits a symptom of limited power.
Application  Key On Engine Off  Key On Engine Running  Continuous Memory 
Ranger GO to Pinpoint Test DH .
All others GO to Pinpoint Test DV .
RENDER: 1.0x

NO RELATED

Recommended Tools & Savings

Use the Manual With the Right Hardware

Pair factory procedures with proven DIY tools so the instructions are easier to execute.

Affiliate disclosure: We may earn a commission at no extra cost to you.

Shop Manual-Ready ToolsFree Quote CheckQuote Shield Pro

When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • • You smell fuel, burning insulation, or see smoke.
  • • Brakes feel soft, pull hard to one side, or make grinding noises.
  • • The engine overheats, stalls repeatedly, or misfires under load.
  • • You are missing required tools, torque specs, or safe lifting equipment.
  • • You are not confident in the next step or safety outcome.