Fault code P2166 is called “Throttle/Pedal Position Sensor (PPS) “D” Maximum Stop Performance” but in different programs it may be called differently. This fault designation applies to all vehicles equipped with OBD-II.
Technical description and explained code P2166
This diagnostic trouble code (DTC) is a generic code. Error P2166 is considered a general code because it applies to all makes and models of vehicles. Although the specific repair steps may vary slightly from model to model.
The throttle position sensor (TPS) reacts to the movement of the accelerator pedal. It is a type of potentiometer. It converts the throttle position into a voltage output and sends a voltage signal to the engine control module (ECM). It also determines the opening and closing speed of the throttle and provides a voltage signal to the ECM.
Code P2166 means that the vehicle’s computer has detected a sensor voltage that is outside the normal operating range. When the throttle is closed, the signal is about 0.45 volts and the lower limit when open is 0.17 to 0.20 volts.
Simply put, the throttle position sensor is used to determine what position the throttle is in. If the signal value is very different from the reference, this code is set.
When this code is stored, the PCM usually puts the vehicle into fail-safe or emergency mode. In this mode, engine acceleration may be severely limited or disabled completely.
Symptoms of vehicle malfunctions
The main signal that an error P2166 has occurred is the Malfunction Indicator Lamp (MIL) is also known as the CheckEngine Light.
It can also be warning signs such as:
- Check engine light on the control panel will illuminate (the code will be stored as a fault).
- Ignition jerking/missing at idle or under load.
- The engine stops or starts badly.
- Engine cannot be accelerated, throttle response is unresponsive.
- Bad acceleration.
- Engine power drop due to slow throttle response.
- Cruise control malfunction.
Error P2166 is considered serious, as it may cause engine and handling problems. If this code is detected, it is recommended that you take corrective action as soon as possible.
Factors that can cause this error code
The error code P2166 can mean that one or more of the following problems have occurred:
- Faulty throttle position sensor “D” or accelerator pedal position sensor.
- Throttle control circuit breakage or bad electrical connection of TPS, PPS and PCM sensors.
- TPS, PPS sensor wiring harness is shorted.
- Throttle valve return spring is jammed.
- Throttle choke clogging.
- Sometimes faulty PCM module is the cause.
How to fix or reset OBD-2 code P2166
Some suggested steps for troubleshooting and fix the error code P2166:
- Read all stored data and error codes with an OBD-II scan tool. To find out when and under what circumstances error P2166 appeared.
- Clear the error codes from the computer memory and test-drive the vehicle to find out if the fault appears again.
- Visually inspect the electrical wiring and connections related to the throttle “D” or accelerator pedal position sensor for looseness and damage.
- Test the TPS, PPS sensor.
- Check the return spring for proper operation.
- Clear error code from computer memory again, test drive vehicle to see if problem is resolved.
Diagnose and repair of problems
Carefully check the throttle position sensor (TPS) or accelerator pedal position sensor (PPS). Inspect connector and wiring for openings, corroded contacts, etc. Repair or replace if necessary to clear error P2166.
Check voltage at TPS, PPS, it should be between 0.45-0.17 volts (some vehicles may have different values). If the voltage is too low or too high, this indicates a problem. Replace the sensor if necessary.
If recently replaced, you may need to adjust the TPS, PPS. On some vehicles, the installation instructions require a proper adjustment or adjustment (see repair manual for details).
If there are no symptoms, the problem may be intermittent, and clearing the code may temporarily resolve it. If this is the case, you should definitely check the wiring to make sure it is not rubbing or frayed anywhere, etc.
On which vehicles does this problem occur most frequently
Fault code P2166 can occur on different vehicles but there are statistics on which brands this occurs most often. Here is a list of some of them:
- Dodge (Charger, RAM)
Fault code P2166 can sometimes be found with other errors. The most common are the following: P2120, P2121, P2122, P2123, P2124.