How severe is this DTC?
A P2168 should be considered severe as it can render the vehicle undrivable.
What are some symptoms of the code?
Symptoms of a P2168 fault code may include:
- Unresponsive accelerator pedal
- Limited or no acceleration
- Engine stalling at idle
- Hesitation during acceleration
- Inoperative cruise control
What are some common causes of the code?
Causes of this throttle/pedal position sensor P2168 code may include:
- Faulty TPS or PPS
- Open or shorted circuits between TPS, PPS and PCM
- Corroded electrical connectors
- Defective DBW actuator motor
What are the P2168 troubleshooting steps?
Check your vehicle information source for Technical Service Bulletins (TSB) matching the make, model and engine size of the vehicle in question. Symptoms and stored codes should also match. If you find a matching TSB, this will greatly assist your diagnosis.
My diagnosis for a P2168 code typically begins with visual inspection of all cables and connectors related to the system. I would also check the throttle plate for signs of carbon buildup or damage. Clean carbon from the throttle body according to manufacturer recommendations and repair or replace any faulty wiring or components as needed, then retest the DBW system.
You will need a diagnostic scanner, digital volt/ohmmeter (DVOM) and reliable vehicle information source to accurately diagnose this code.
Next, connect the scanner to the vehicle’s diagnostic port and retrieve all stored fault codes. Record them in case you need the information later in your diagnosis. Also save any associated freeze frame data. These notes may prove useful, especially if P2168 is intermittent. Now clear the codes and test drive the vehicle to see if the code resets.
If the code immediately resets, voltage spikes and inconsistencies between TPS, PPS and PCM can be detected using scanner data stream. Narrow the data stream to display only relevant data for faster response. If no spikes and/or inconsistencies are detected, use the DVOM to retrieve live data from each sensor signal wire. To retrieve live data with DVOM, connect the positive test lead to the appropriate signal wire and the ground test lead to the ground circuit, then observe the DVOM display while operating the DBW. Look for voltage spikes when the accelerator is slowly operated from closed position to wide open throttle. Voltage typically ranges from 0.5 volts at throttle closed to 4.5 volts at wide open throttle, but consult your vehicle information source for exact specifications. If spikes or other irregularities are detected, suspect the tested sensor is faulty. An oscilloscope is also an excellent tool for testing sensor operation.
If the sensor operates as expected, disconnect all associated controllers and test individual circuits with the DVOM. Repair or replace system circuits as needed.
Only suspect a faulty PCM or PCM programming error after all system sensors and circuits have been verified.
Some manufacturers require the throttle body, throttle actuator motor and all throttle position sensors to be replaced as a single unit