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GTECH Calibration
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P1122

Throttle Position Higher Than Expected.

  • Honda
  • Powertrain
  • Manufacturer code
  • Medium severity

How this code is built

P
SystemPowertrain
1
Defined byThe manufacturer
1
AreaFuel and air metering
22
FaultThe specific fault in that area

What it means

On a Honda, P1122 means the engine control unit has seen a throttle position reading higher than it expected for the conditions, such as a throttle angle that does not match airflow, load or the driver's pedal demand. The throttle position signal and the other inputs it is compared against have disagreed, so the fault is stored and the warning light comes on. The exact comparison and the affected engines vary by model and year, so check the model-specific procedure.

Symptoms

  • Malfunction indicator lamp on
  • Unstable or hunting idle
  • Hesitation or poor response when pulling away
  • Engine surging at light throttle
  • Reduced power or limited throttle response
  • Occasional stalling at idle

Possible causes

  • Dirty or carbon-fouled throttle body causing the throttle angle to disagree with airflowlikely
  • Faulty or worn throttle position sensor, or an internal fault in an electronic throttle bodylikely
  • Damaged wiring, poor connector contact or corrosion in the throttle position signal, reference or earth circuitpossible
  • Air leak after the throttle body or a vacuum leak making airflow differ from the throttle anglepossible
  • Faulty accelerator pedal position sensor or a related airflow or pressure sensor giving a conflicting readingpossible
  • Fault inside the engine control unit or an outdated calibration, where a known update exists for the modelrare

How to diagnose

  1. Read all stored and pending codes and note the freeze frame data, including throttle angle, engine load, engine speed and coolant temperature.
  2. Check for any related codes for the pedal sensor, airflow or manifold pressure sensor, as they may point to the real fault.
  3. Inspect the throttle body connector, wiring and earth for damage, corrosion, water ingress or loose pins, and wiggle test while watching live data.
  4. Inspect the intake system for split hoses, loose clamps and vacuum leaks, and check the throttle body bore for heavy carbon build-up.
  5. Watch live throttle position data from closed to fully open and check it moves smoothly, with no dropouts or jumps, and returns to the correct closed value.
  6. Compare live throttle position against pedal position, load and airflow readings to see which input disagrees.
  7. Check the sensor supply voltage, signal and earth with a multimeter against the model's specification.
  8. Check with the manufacturer for any technical bulletins or calibration updates relevant to the model and engine.

How to fix

  • Clean the throttle body using the correct method for the model, then complete any required idle or throttle relearn.
  • Replace the throttle position sensor or throttle body assembly if it is faulty, then perform the relearn procedure.
  • Repair or replace damaged wiring, terminals or connectors in the sensor circuit.
  • Repair any intake leaks by replacing split hoses, seals or gaskets.
  • Replace a faulty pedal sensor or other conflicting sensor once testing confirms it.
  • Apply an official calibration update only where an outdated calibration is confirmed as the cause.

Can I keep driving?

Medium severity

The car can usually be driven short distances, but have it checked soon as hesitation, stalling or reduced power could make it unsafe in traffic. If the engine stalls repeatedly or goes into limp mode, stop driving it until it is repaired.

Guide written by AI from the code's definition. Confirm with a diagnosis before replacing parts.

This code for other makes

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