Diagnostic Head

Diagnostic Head

The diagnostic head is the link between the vehicle's electronic systems and the MoDiC tester.

The head is a self-contained computer that receives its power from the diagnostic socket when the head is plugged in.

The diagnostic head has 3 MB of data storage and a PCMCIA card for storing and transmitting data to the MoDiC.

The size of the diagnostic head has been kept small so that it can fit under the hood when it is closed. Future plans call for the head to be used as a flight recorder that can be attached to the vehicle and record data on a suspect system while the vehicle is being driven

Data from the diagnostic head can be transmitted to the MoDiC either by Radio Frequency (RF) or by a hard wire cable link. The RF transmitting range is approximately 950 feet and the hardwire cable is 25 feet long.

The diagnostic head has four connectors:
- Bottom edge: Two single connectors (red/black) used for signal recording for future usage and one multi-pin connector for the 20 pin diagnostic socket or OBD II DLC.
- Top edge: COM connector for 25' wire link between Head and MoDiC.

The diagnostic head contains a status LED and a data recorder button (future use) on the side.

If the flight recorder button is pressed, the head goes into the record mode and communication between the head and the MoDiC is interrupted (make sure button is in the off position).

Connect the head with the 20 pin connector to the vehicle with the ignition key off. Switch ignition on and watch the Head Status LED. The status LED provides the following information in regards to the diagnostic head operation:

LED DISPLAY INDICATION
Off No power supply to the diagnostic head
Green - short flashes Diagnostic head establishing the communication link
Green - long flashes No connection possible
Green - steady Diagnostic head communication link established
Orange - slow flashing Faulted connection
Orange - rapid flashing Temperature limit of Diagnostic head exceeded

Temperature Monitoring

If the temperature threshold of the diagnostic head is reached, a warning display will appear on the MoDiC screen. The diagnostic procedure should be terminated and the head allowed to cool down.

If the temperature threshold is exceeded, the diagnostic head will switch itself off and the connection to the MoDiC will be terminated. Once the head has cooled down, the diagnostic link can be reestablished.