What is the reason for the Passat not having idle speed?

1 Answers
VanGenevieve
07/29/25 11:25pm
Passat does not have idle speed for the following reasons: Intake pipe leakage: Fault analysis: According to the idle speed stability control principle of the engine, under normal circumstances, the opening degree of the idle speed control valve and the intake air volume strictly follow a certain functional relationship, that is, as the opening degree of the idle speed control valve increases, the intake air volume increases accordingly. If there is a leak in the intake pipe, the intake air volume and the opening degree of the idle speed control valve will not strictly follow the original functional relationship, meaning there will be sudden changes in the intake air volume as the idle speed control valve changes. The air flow meter cannot measure the true intake air volume, causing the ECU to inaccurately control the intake air volume, resulting in unstable engine idle speed. Idle speed switch not closing: Fault analysis: If the idle speed contact is disconnected, the ECU determines that the engine is under partial load. At this time, the ECU determines the fuel injection volume based on the signals from the air flow meter and the crankshaft speed. However, the engine is actually operating under idle conditions with less intake air, causing the mixture to be too rich and the speed to rise.
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