Self-Test

Tech 2 Connecting:

If necessary, the Tech 2 can also perform more in-depth self-tests. Although this function is mainly intended for repairs, it may be useful in helping the operator to pinpoint a problem.

Before Tech 2 self-tests are carried out, the following steps must be taken (see illustration above):
1. Check that the PCMCIA card is correctly inserted in the "0" port, the upper slot on the left. Also check that the read/write protection is located on the left (see arrow in the illustration above).
2. Plug the RS232 cable termination into the RS232 communications port.
3. Connect the diagnostics cable to the Tech 2.
4. Connect the VCI cable termination to the vehicle end of the diagnostic cable.





Select "F3: Self-test" to see the list of available self-tests.





Mark "F0: Automated PCB and VCI" and press "ENTER" to test the components on the main printed board assembly and in the communications interface.





Automated Main PCB and VCI
The components on the main printed board assembly and in the communications interface are tested automatically. This test is the most practicable since it limits the trouble to a single unit. The fault is diagnosed as being in either the Tech 2, the VCI module or the cables.

Select "F0: Automated Main PCB and VCI" and press "ENTER" to perform the test.





If the VCI cable termination is not connected to the Tech 2, the menu on the right will be displayed. In such case, connect the VCI cable termination (see illustration "Tech 2 Connecting" at beginning of this article) and press "ENTER" to continue.





During the test the operator is requested to press each key in turn.

Press "F0".





For each key that is pressed, the Tech 2 will indicate whether it is OK or not. The operator will then be requested to press the next key.

Follow the instructions for completing the keypad test.





When the keypad test has been completed, first the menu on the right will be displayed with the message "Test in Progress" to indicate that a self-test of the VCI interface is in progress.





When the keypad and the VCI interface have been tested, the display will show the test status in the menu as shown on the right.

^ The "Pass" message and a zero opposite "Total failures" indicate that the equipment is in proper working order. In such case, press "EXIT' to return to the main menu.

NOTE: If the equipment passes the test but there is a communications problem with a vehicle, the adapter may be at fault. This can be checked to some extent with the ID test, see "F4: Selectable VCI".

^ A "Fail" message and the figure 1 or higher indicate a problem in one or more areas. Make a note of all fail messages and report them to the service department.

If the fail messages include any of the following
1. "DLC 1...Fail (VCI Data Communication Link 1.)"
2. "DLC 2... Fail (VCI Data Communication Link 2.)"
3. "CCD... Fail (VCI Collision Detection.)"
4. "Loopback Fail...(VCI Loopback Circuits.)"

Remove the diagnostics cable and the VCI termination. Then plug the VCI termination straight into the VCI module and carry out a new test.

^ "Pass" and a 0 opposite "Total failures" indicate that the fault is in the cable.
^ "Fail" and a 1 or higher figure indicate a problem in the VCI module.

NOTE: This could be caused by a low power supply. Check this by means of the special test for the cable termination (see "F4 Selectable VCI").





F1: Automated Main PCB
As F0 but only tests the main printed board assembly.

F2: Automated VCI
Tests only the communications interface in the same manner.

NOTE: The Tech 2 must never be plugged into a vehicle's data link connector when performing a self-test.

F3: Selectable Main PCB
Retrieve a submenu for selecting special parts. This menu is generally intended for tests in connection with the repair of units.

F4: Selectable VCI
Also retrieve a submenu which shows special tests to facilitate repairs. Two of these tests are of interest to the technician, however:

1. Test of VCI cable termination to measure the power supply.
^ Use the display key for selecting "More tests" and move to the other display.
^ Mark "F5: VCI Loopback" and press "ENTER". Clear instructions are given in the following display for testing modules, connectors and power supplies. If the power supply is lower than 9 volts, connect an alternative power supply and carry out a new test.

2. ID test of adapter to check which adapter is connected.
^ In the first display select "F1: VCI ID" and press "ENTER".
^ Follow the instructions on the display to confirm that the adapter is recognized.
^ If the adapter is not recognized, change it and perform a new test.

F5: Power On Self Test Results
Repeats the fail display that is shown immediately after the self-test with equipment turned on.





TIPS
If:
^ The Tech 2 fails to start, try another power supply.
^ There is no display, try adjusting the contrast.
^ The display appears to have dead areas/pixels, use "Selectable main PCB" to perform a "Display Controller" test and check the display in black-and-white.
^ The Tech 2 has communications problems, check all cable connections again.
^ The Tech 2 is very cold or hot, it may prove impossible to set the desired contrast level. In such case, this is because the display is sensitive to temperature and the trouble will go away when the Tech 2 attains normal operating temperature again.

Self-Test With Equipment Turned On:

Display Message Explanations

Main Printed Board Assembly:

Automated Main PCB and VCI





Communications Interface For Vehicles