A throttle actuator control motor electronically controls drive-by-wire systems on cars that have the feature. The gas pedal has a sensor that signals the throttle actuator control motor to open or close the throttle plate on demand.
If the powertrain control module (PCM) detects a weaker voltage from the throttle actuator control motor, then a P2118 code, along with a check engine light, is triggered.
When this code is set, the vehicle goes into a failsafe mode to prevent further damage. This mode can only be resolved when normal operation is restored.
What Does Code P2118 Mean?
Diagnostic trouble code (DTC) P2118 stands for “Throttle Actuator Control Motor Current Range/Performance.” Note that this code does not appear in every vehicle’s code library.
The PCM controls the ETC system by monitoring its throttle position sensors. These sensors provide throttle angle feedback to the vehicle’s computer.
As the driver steps on the accelerator pedal, the APP sensor sends a signal to the PCM to determine how much power is being requested from the engine. This will then allow the throttle plate to open or close accordingly.
If the PCM detects higher than normal current is required to move the throttle plate, a code P2118 will be stored. The PCM may also put the engine into a “limp home mode” or “fail-safe” position to prevent unwanted acceleration.
Potential Causes of a P2118 Code
Possible causes of this code may include:
- Faulty throttle body
- Dirty throttle plate or linkage
- Faulty throttle position sensor
- Defective accelerator pedal position sensor
- Throttle actuator control motor is defective
- Corroded or damaged connector
- Faulty or damaged wiring
- Faulty PCM.
P2118 Code Symptoms
- Symptoms of a P2118 trouble code may include:
- Engine will not start
- Poor performance that worsens over time
- Lack of throttle response
- Check Engine Light illuminated
- Smoke from the tail pipe
- Increased fuel consumption
How to Fix P2118
DTC P2118 is a generic powertrain code that applies to OBD-II equipped vehicles with an electronic throttle control system.
While different makes may exhibit similar symptoms and causes related to the code, the steps for diagnosing and repairing each vehicle may vary depending on the automaker’s specifications.
Check for TSBs
The first step in the troubleshooting process for any malfunction is to research the Technical Service Bulletins (TSB’s) for the specific vehicle by year, model, and power plant.
The second step is to locate all of the components associated with the Throttle Actuator Control System, including the throttle body, throttle position sensor, throttle actuator control motor, PCM, and accelerator position sensor in a simplex system.
The last visual and physical inspection involves checking the throttle plate. With the ignition switch off, try rotating the throttle plate by pushing on it. It should rotate to the wide open position. If there is sludge behind the plate, clean it while it is accessible.
Advanced Steps
The advanced steps are vehicle-specific and require advanced equipment for accurate performance.
These procedures involve using a digital multimeter and specific technical references for the vehicle. Voltage requirements vary based on the specific year, model, and engine of the vehicle.
Circuit Checks
With the ignition switch off, disconnect the electrical connector at the throttle body. Locate the 2 pins that go to the motor or motors on the throttle body. Use a digital ohmmeter set to ohms to check the resistance of the motor or motors.
The motor should read approximately between 2 and 25 ohms, depending on the specific vehicle (check manufacturers specs for your vehicle).
If the resistance is too high or too low, the throttle body will need to be replaced. If all tests have passed so far, check the voltage signals to the motor.
How Much Does It Cost to Fix a P2118 Code?
To fix a P2118 code, which typically indicates a problem with the throttle actuator control motor, you can expect to pay between $200 and $500 depending on the vehicle make and model, with the majority of the cost coming from labor to replace the faulty motor, rather than the part itself.