Specifications

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Appendix A Troubleshooting and
Communication Problems
Startup Troubleshooting
If the display does not light up when you connect the Scanner to vehicle power, check:
• The Scanner battery, located under the left handgrip.
• For a blown cigarette lighter fuse on the vehicle if using the cigarette lighter power cable.
• For bent or broken pins on both ends of the data cable and on the test adapter.
• For a loose cable connection.
• For an open ground wire in the vehicle connector wiring harness.
• For correct connection at the battery if you are using the battery power adapter.
Replace the internal battery if the Scanner operates erratically in any way or if recorded data is
not retained in the Scanner memory.
If the display is very dim or nearly blank when you apply power to the Scanner, remove the
internal battery with the Scanner disconnected from vehicle power. Hold down the Quick ID
Button for 5 seconds to clear the Scanner memory. Then reinstall the battery.
If one or more segments of the display do not light during the display check, you may not get
valid readings when viewing data or doing functional tests.
See “Communication Problems” on page 98 for information on what to do if a vehicle does not
communicate with the Scanner.
Communication Problems
To test Mercedes control systems, the Scanner must communicate with the engine or
transmission controller and receive vehicle data over a data link.
The speed at which the Scanner operates and displays data depends on the number of data
parameters and how busy the control system is on the vehicle.
This can affect how quickly the data changes on the Scanner display and the length of time it
takes to display a movie. Differences in Scanner operation will vary from vehicle to vehicle. On
one car, data readings may appear to change almost instantly, while on another vehicle, data
changes may occur much slower.
The Data and Codes selections from the Main Menu require the Scanner to communicate with
the vehicle control module. The ignition must be on to establish communication. After selecting
Data or Codes, the Scanner displays an initializing message.
If communication is not established within 5 seconds, the Scanner displays a “no
communication” message. Return to the System List Menu and check the items listed below
under Common Problems.