The Hella oil level sensor, often referred to as the PULS (Packed Ultrasonic Level Sensor), is a sophisticated component utilizing ultrasonic technology to determine engine oil levels. This sensor incorporates an onboard computer and measures oil level by emitting ultrasonic signals that reflect off the oil’s surface. The time it takes for the signal to return is then calculated to determine the oil level. This intricate system can sometimes trigger frustrating issues. This article explores how to disable the oil level sensor using VCDS (VAG-COM Diagnostic System).
Understanding the Complexity of the Oil Level Sensor
The Hella oil level sensor integrates an ultrasonic sensor, a temperature sensor, and an ASIC (Application Specific Integrated Circuit) into a single multi-chip module. This compact design enhances resistance to shock and vibration. The sensor’s damping cup, with openings at its base and tip, ensures a consistent oil flow and stabilizes the measurement process, especially in dynamic conditions.
While VCDS allows for various coding modifications, disabling the oil level sensor directly through coding within the instrument cluster might not be possible. Hella’s documentation indicates that analyzing the sensor’s signal with an oscilloscope can confirm signal transmission to the control unit. However, this method doesn’t guarantee proper sensor functionality. The oscilloscope reading only shows if a signal is being sent, not if it’s the correct signal.
Exploring Alternatives to Disabling the Oil Level Sensor
Given the complexity of the sensor’s signal, which combines temperature and level information into a single waveform, simply disabling it might result in the loss of oil temperature data. If direct coding with VCDS isn’t feasible, a potential workaround involves simulating a “good” sensor reading. This would require scoping a known good reading and creating a circuit that continuously replicates that signal to the control unit.
However, this method presents challenges. Developing a circuit that accurately mimics the complex waveform, including both oil level and temperature information, can be technically demanding. Furthermore, it’s crucial to ensure the simulated signal remains consistent across different engine operating conditions. While this approach might disable the faulty sensor’s error messages, it’s essential to weigh the potential risks and complexities before implementing such a solution. Regular manual oil level checks using the dipstick remain crucial even if a workaround is implemented.
