* Throttle Position Sensor (TPS): This sensor tells the PCM (Powertrain Control Module) how far the gas pedal is pressed. A faulty TPS can lead to no power or erratic performance. This is a very common culprit.
* Pedal Position Sensor (PPS): Similar to the TPS, but this sensor is located on the pedal assembly itself. A malfunction here can also prevent the engine from receiving the signal to increase throttle.
* Accelerator Pedal Module (APM) / Pedal Assembly: This is the entire assembly containing the PPS and other related components. A problem within this module can cause various issues, including no throttle response.
* Wiring harness: Damaged or corroded wiring between the pedal assembly, TPS, and PCM can interrupt the signal. This is especially prevalent in older trucks exposed to the elements.
* PCM (Powertrain Control Module): While less common, a faulty PCM can prevent it from interpreting signals from the sensors correctly.
* Fuel System Problems: While the gas pedal itself might be functioning, problems like a clogged fuel filter, fuel pump failure, or injector issues could prevent the engine from responding to increased throttle input. You might feel like the gas pedal isn't working, but the real issue is fuel delivery.
* Vacuum Leaks: In some scenarios, significant vacuum leaks can affect throttle response and make it feel like the pedal is unresponsive.
* Throttle Body: A dirty or sticking throttle body can prevent the throttle plate from opening properly.
To diagnose the problem, you'll likely need:
* A code reader: This will help identify any diagnostic trouble codes (DTCs) stored in the PCM. A code reader that can read Ford Powerstroke codes specifically is ideal.
* A multimeter: To test the voltage and resistance of the TPS, PPS, and related wiring.
* A mechanic (possibly): Unless you have experience working on diesel engines, it's often best to have a qualified mechanic diagnose and repair the issue. This is especially true given the complexity of the 7.3 Powerstroke system.
Simply stating "the gas pedal doesn't work" isn't enough information to determine the cause. Any accompanying symptoms (check engine light, unusual noises, smoke, etc.) will significantly help in narrowing down the potential problems.
