* Throttle Position Sensor (TPS) failure: This sensor tells the engine control module (ECM) how much the throttle is open. A faulty TPS can send incorrect signals, causing the ECM to cut fuel or ignition, resulting in a sudden loss of power or a complete stall. This is a very common culprit.
* Throttle Actuator (if electronically controlled): Many modern vehicles use an electronic throttle, controlled by a motor. A faulty actuator motor, its wiring, or its control circuitry within the ECM can prevent the throttle plate from opening.
* Throttle body itself is clogged or sticking: Dirt, grime, carbon buildup, or even a sticking linkage (on older vehicles with a cable) can prevent the throttle plate from moving freely.
* Vacuum leak: A significant vacuum leak in the intake system can disrupt the engine's ability to operate correctly, and this might manifest as a sudden loss of power when you press the gas pedal. This affects the throttle's ability to control the air intake properly.
* Mass Airflow Sensor (MAF) failure: The MAF sensor measures the amount of air entering the engine. A faulty sensor could send incorrect readings to the ECM, leading to incorrect fuel delivery and potentially stalling or a lack of response.
* Wiring harness issues: Damaged or corroded wiring to the throttle body, TPS, or actuator can interrupt signals and cause malfunctions.
* ECM/PCM failure: Though less likely, a problem with the engine control module itself (also called the powertrain control module, PCM) could cause this issue. This is usually indicated by other problems as well.
* Low fuel pressure: While less likely to cause an immediate "die," insufficient fuel pressure could cause the engine to sputter and die under load.
To diagnose the problem:
You'll likely need a code reader (OBD-II scanner) to check for diagnostic trouble codes (DTCs) stored in the ECM. These codes can pinpoint the most likely culprit. Beyond that, visual inspection of the throttle body for cleanliness and proper movement, and checking the wiring harness are good next steps. If you're not mechanically inclined, taking it to a mechanic is recommended, as troubleshooting fuel systems can be complex.
