What does it mean when the throttle position sensor 1-2 is unreasonable?
2 Answers
An unreasonable position between sensor 1 and 2 is generally caused by the throttle. If the throttle has been replaced with an original equipment manufacturer (OEM) part, it is recommended to check whether the wiring from the throttle connector to the engine control unit (ECU) connector is damaged. Use a diagnostic tool to check the signal voltage of the throttle position sensor. In such cases, cleaning the throttle and performing a reset can be attempted. If the issue persists, replacing the throttle may be necessary. The functions of the throttle position sensor are as follows: 1. Detecting operating conditions: The throttle position sensor, also known as the throttle opening sensor or throttle switch, primarily detects whether the engine is in idle, load, acceleration, or deceleration conditions. It essentially consists of a variable resistor and several switches, installed on the throttle body. 2. Two contacts: The resistor's rotating shaft is linked to the throttle and has two contacts: a full-open contact and an idle contact. When the throttle is in the idle position, the idle contact closes, sending an idle condition signal to the ECU. When the throttle is in other positions, the idle contact opens, outputting a voltage signal corresponding to the throttle's rotation angle. The ECU uses this signal voltage to determine the engine's load and identifies acceleration or deceleration based on the rate of change in the signal voltage over time. The ECU uses this information to adjust fuel injection or perform fuel cut-off control.
Last time at the repair shop, the mechanic explained that 'Throttle Position Sensor 1-2不合理' simply means the two signals from the sensor don't match. It's supposed to work in sync like both hands cooperating, but now one says the throttle is at 30% while the other insists it's 50%, leaving the ECU completely confused and triggering an alert. Most likely, it's due to worn contacts or carbon buildup inside the sensor, or maybe rodents chewed through the wiring. My neighbor's Hyundai had this exact issue recently – erratic idle speed like it was possessed – and replacing it with an OEM sensor fixed it for around 300 yuan. Remember not to keep driving with this problem, or the engine might activate speed limit protection on you.
