What are the 91 and 93 group data streams of Volkswagen?
2 Answers
Here is the relevant introduction about Volkswagen data streams: 1. Definition: The automotive data stream refers to the data parameters exchanged between the Electronic Control Unit (ECU) and sensors/actuators, which are read by a dedicated diagnostic tool through the diagnostic interface. These parameters vary over time and operating conditions. The data transmission is like a queue, with each piece of data flowing one by one through the data line to the diagnostic tool. 2. Function: The data stream stored in the automotive Electronic Control Unit (ECU) accurately reflects the working voltages and states of various sensors and actuators, providing a basis for automotive fault diagnosis. The data stream can only be read by specialized diagnostic equipment. Automotive data streams serve as the input and output data for the car's ECU, allowing maintenance personnel to monitor the vehicle's working condition in real-time and diagnose faults promptly. Reading automotive data streams can detect the working status of various sensors and the vehicle's operating condition. Additionally, operational data of the vehicle can be configured through the data stream.
To be honest, I often work with Volkswagen's data streams in the workshop, and Groups 91 and 93 are like old acquaintances in the ECU. Group 91 mainly contains data related to intake pressure, displaying values such as current atmospheric pressure and intake manifold absolute pressure. By looking at it, you can tell exactly how much air the engine is taking in—especially important for turbocharged cars, as abnormal pressure directly affects power output. Group 93 focuses on air-fuel mixture concentration, with both long-term and short-term fuel trims displayed here. I always keep an eye on these two values when repairing cars. If the numbers deviate by more than ±10%, it usually indicates an air leak or an issue with the oxygen sensor. The exact content displayed in these groups may vary slightly between different models, but the core purpose is always to monitor the engine's breathing and fuel consumption status.
