The fault we will discuss in this post is a common fault, we will use a real case to show how we fix this fault.

Vehicle information

Model: Audi A4

Mileage: 3046KM


Fault symptom

Due to the engine oil light on, the customer came to the store to add oil and used T40178 to check that the oil level was normal after filling up, but the MMI showed that the oil level was at the lower limit.


Diagnose process

1. There are three prerequisites for automatic oil level detection, the engine speed, the vehicle's driving state (this item is determined by the longitudinal and lateral acceleration sensors in the ESP system), and the switch signals for opening / closing the engine compartment cover. If there is no trigger to open or close the engine compartment cover, the computer will always be unable to update the data information of the current oil level sensor.

2. As there is no other fault and the engine speed is normal, so we can first check engine compartment cover.

3. Remove the plug on the engine compartment lock, jumper wire the pins, and the dashboard shows that the compartment cover is open. Remove the jumper, and the dash will show that the cover is closed. In this way, it is artificially simulates the open and closed state of the engine compartment cover for the central electrical control unit J519 module. Drive the car, the MMI display the oil level is normal, no fault appears.


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