Notes For Hand Held Tool (HHT)
WARNING: This page is about a different car, the 1996 Mercedes-Benz C220, 1995 Mercedes-Benz C220, and 1994 Mercedes-Benz C220. However, it is still accessible from the selected car via links, so may be relevant.
- Fault Search With HHT
Diagnostic trouble code (DTC) memory: Select "Current DTC's". If the actual condition changes, e.g. when wiggling a connector, the change is reported optically and acoustically so that troubleshooting can be performed directly with the HHT. - Loose Connections
Loose connections are stored if they occur several times in a certain time period. Therefore, they can appear only as "Stored DTC's" and never as "Current DTC's". - Nominal Values
All nominal values are relative to the actual values shown on the HHT. - Actual Values For Coolant Temperature, Intake Air Temperature & Air Mass
In case of an open or short, the actual value is immediately replaced by a substitute value which is very close to the actual value. Therefore, a fault can not be recognized clearly. A readout of the fault is possible only via the diagnostic trouble code (DTC) memory. - Actual Value For Engine RPM
In case of the engine RPM's, the HHT display shows the closed throttle (idle) speed nominal value calculated by the control module on the left and on the right, the RPM actual value. Both values should differ from each other only slightly. The permissible tolerances are not yet known.