Mode 7
Data Output with a Scan Tool
The output of data relevant to OBD from the control modules was stipulated by law for the USA. It is described in SAE J 1979.
Data output is subdivided into different modes.
Mode 7
Output of test results of continuous tests. (Output of suspected faults)
The data sets in the modes are referred to as Parameter Identification (PID).
After being stimulated by a generic scan tool, all systems relevant to OBD log on with their address. In vehicles with ME 7.2 this is the DME with the address $11 and in Tiptronic vehicles it is the transmission control module with the address $1A.
NOTE: The $ symbol means that a hexadecimal number is involved.
When the control module provides data, it also states the mode, the PID number and the address of the control module.
Example:
Mode 41Pid$01 Adr$11
Engine control
No. of faults: 0
MIL commanded OFF
Data output takes place
with Mode 41 in Mode 1,
with Mode 42 in Mode 2,
with Mode 43 in Mode 3 etc.
Mode 7
The Diagnostic Trouble Codes of all non-shedded, officially relevant* faults are displayed in Mode 7. This mode has the same structure as Mode 3.
* Faults which switch on the Check Engine warning light