Some details about the Buick Scanmaster G.
The Scanmaster can be installed and connected 2 different ways, either directly receiving "ALDL" data from the cars ECM at about update every 1.5 seconds, or to a PowerLogger which reads data from the internal circuitry of the ECM and provides much more data at 8 - 18 updates per second (some data is slowed to make it readable). ALDL mode is limited by the ECM's datastream which does not include wideband AFR information.
ALDL mode is generally used by casual tuners and daily drivers.
In either mode, the Scanmaster G will store the highest knock retard and leanest Air/Fuel reading durring a full throttle run. This data can be retrieved afterwards until the engine is shut off, or another full throttle run is made.
In either mode, the data can be monitored and recorded using an android device connected via wireless/Bluetooth to the unit. This is done using the ALDLDroid app available on Google Play. A configuration file ("ADX file") needs to be downloaded from the downloads section of this site and loaded into the Android device. The Android device is "paired" to the unit (pairing code 1234). The ALDLDroid app is set to connected to the Sanmaster G bluetooth device and the correct ADX file is selected. Then the Android device will monitor, record, and review data from the Scanmaster G. Refer to the ALDLDroid documentation for more details. There is no equivalent app for Apple/IOS devices.
When used with a PowerLogger, the data rate is much higher and the data contains wideband AFR info (when there is a wideband system installed in the car), as well as Boost Pressure info (a MAP sensor must be connected). Additionally, more ECM data is available (all BLM information, injector pulsewidth, wastegate dutycycle, etc). When using the PowerLogger, the Scanmaster G can record full PowerLogger data internally during a full throttle run, to be retrieved later, even after shutting the engine off or making an additional full throttle run. These stored logs are retrieved using the PowerLogger's Windows App ("PLC"). If ALDLDroid is used to record data, this data can be converted into PowerLogger format for review and analysis.
For serious tuning and racing a PowerLogger is recommended for maximum benefit.