What happens when a car's throttle position sensor fails?
1 Answers
When the throttle position sensor fails, the symptoms include: 1. Poor contact at the idle contact point, resulting in no idle signal, causing the engine to have no idle or unstable idle. Poor contact at the no-load contact point leads to no full-load signal input, resulting in the engine having no high speed or difficulty accelerating. 2. The engine control unit (ECU) adjusts fuel injection and ignition timing based on the throttle opening. If the throttle is damaged, the ECU cannot correctly receive the throttle opening signal, leading to inaccurate fuel injection and ignition timing adjustments. In severe cases, the engine may fail to start. Below are the reasons for throttle position sensor failure: 1. Corroded connectors causing poor contact, low voltage, or no conduction, leading to the engine stalling easily or difficulty starting. 2. Misaligned initial position, resulting in excessively high or low output voltage, causing unstable idle speed that is either too high or too low. 3. Coating failure leading to resistance changes, causing inaccurate output voltage, resulting in jerky starts and poor acceleration. 4. Excessive carbon buildup at the throttle, preventing it from closing properly, affecting output voltage and airflow values, leading to incorrect air-fuel ratio and unstable idle speed.
