What Causes P0117 Engine Coolant Low Voltage?
2 Answers
P0117 engine coolant low voltage is related to issues such as the oxygen sensor and other factors. Below are specific explanations regarding the P0117 trouble code: 1. Oxygen Sensor: When the oxygen sensor malfunctions, the ECU cannot obtain this information and thus cannot determine if the injected gasoline amount is correct. An improper air-fuel ratio can lead to reduced engine power and increased emissions pollution. 2. Wheel Speed Sensor: Its primary function is to collect the vehicle's speed to detect signs of wheel slip. Therefore, a dedicated sensor is used to collect wheel speed data, typically installed on the hub of each wheel. If the sensor is damaged, the ABS will fail. 3. Intake Pressure Sensor: As the name suggests, the intake pressure sensor detects a series of resistance and pressure changes based on the engine's varying speed and load, converting them into voltage signals for the ECU to adjust fuel injection and ignition timing. It is usually installed near the throttle body. If it malfunctions, it can cause difficulties in ignition, unstable idle speed, and lack of acceleration power.
I've encountered this trouble code before, and it turned out to be a faulty coolant temperature sensor. This component measures water temperature on the engine, and low voltage indicates it might be clogged with scale or have wiring damaged by rodents causing a short circuit. Once during a summer road trip, my dashboard temperature gauge went haywire, and the code read P0117 - turned out to be coolant leakage corroding the sensor connector. I recommend first checking for loose or oxidized wiring connections, then testing the sensor's resistance. At 20°C, it should read around 2 kilohms when functioning properly. If you don't replace a bad sensor promptly, the ECU will misinterpret it as a cold engine condition and over-fuel, which can increase fuel consumption by 30% and make the exhaust smell terrible.
