Error Code P1225 is defined as Closed Throttle Position Learning Performance Problem. This code happens when there is a closed throttle position learning value that is excessively low.

This error code is a generic trouble code, meaning it applies to all vehicles equipped with OBD-II system, especially those made since 1996 up to present. Specifications on the definition, troubleshooting, and repairs, of course, vary from one make and model to another.

Definition

The Electronic Throttle Control Actuator is composed of throttle control motor, throttle position (TP) sensor, etc. Throttle Position (TP) sensor works by responding to the throttle valve movement. It comes with two sensors are potentiometers, which works by transforming the throttle valve position into output voltage, and emit the voltage signal to the PCM (powertrain control module, also known as ECM or engine control module).

Aside from which, the sensors also detect the opening and closing speed of the throttle valve and feed the voltage signals to the PCM. The PCM then judges the current opening angle of the throttle valve from these signals, while the PCM controls the throttle control motor, making the throttle valve open a proper angle in response to the driving condition.

Common Symptoms

The most common symptom and usually the primary symptom for this code is the illumination of the Check Engine light.

Possible Causes

This code reports a sensor fault, but just replacing the sensor will not resolve the underlying problem. In many cases, the error is caused by faulty wiring or poor electrical connection in the Electronic throttle control actuator (TP sensor 2).

Other possible causes include:

  • Faulty electronic control actuator (TP sensor 2)
  • Open or shorted electronic control actuator (TP sensor 2) harness

How to Check

To diagnose for this error code, technicians usually start by checking the electrical connection in the electronic throttle control actuator (TP sensor 2).

Then, they proceed on checking the electronic control actuator itself and look for faults.

Lastly, they look for open or shorted electronic control actuator harness.

How to Fix

Repairs for this error code are pretty simple, which of course, can only be derived from a thorough diagnosis. Some of the most common fixes are:

  • Fixing faulty electrical connections in the electronic throttle control actuator
  • Repair or replacement of the electronic control actuator itself
  • Repair or replacement of shorted or open electronic control harness

This code usually indicates a short to ground on the various injector and solenoid circuits. Circuits are powered by the fuel pump relay. Thus, if the output voltage of the fuel pump is below than expected during cranking, it may generate multiple short to ground codes for fuel pumps can be produced. In other cases, the problem could be caused by a defective fuel pump relay.