How to Use the Diagnostic Readout Box

Fig. 10 Diagnostic connector location.:

The Diagnostic Readout Box II (DRB II) must be used to enter the system into one of five test modes:
A. DIAGNOSTIC TEST MODE
B. CIRCUIT ACTUATION TEST MODE (ATM)
C. SWITCH TEST MODE
D. SENSOR TEST MODE
E. ENGINE RUNNING TEST MODE

These five test modes are required to diagnose the system. To use the tester, proceed as follows:

1. Connect the diagnostic readout box Serial Communication Interface (SCI) to the SMEC connector located near the left front shock tower, then connect the red power supply lead to the positive battery terminal.
2. Plug the desired cartridge into the readout box. For a few seconds a test pattern, then an identification logo will appear on the display. After a few more seconds the display will read ``Select Model Year.''
3. Press the F1 or F2 key until the display indicates ``1988,'' then press the Yes key. The display will now read ``Select System.'' If at this time you wish to return to ``Select Model Year,'' press the No key.
4. Press the F1 or F2 key until the display indicates ``Powertrain,'' then press the Yes key. The display will now read ``Select Engine.'' If at this time you wish to return to ``Select System,'' press the No key.
5. Press the F1 or F2 key until the display indicates ``EFI/Turbo,'' then press the Yes key. The display will now read ``Select Test.'' If at this time you wish to return to ``Select Engine,'' press the No key.
6. At this point, one of two tests must be selected: ``Engine Off Test'' or ``Engine Running Test.'' If the Diagnostic Test Mode, Switch Test Mode, Circuit Actuation Test Mode (ATM Test) or Sensor Test Mode is required, select the ``Engine Off Test.'' If the Engine Running Test Mode is required, select the ``Engine Running Test.'' Press the F1 or F2 key until the desired test is displayed on the readout, press the Yes key, then proceed to the desired test mode as outlined under ``Test Modes.'' If at this time you wish to return to ``Select Test,'' press the No key.






The Diagnostic Readout Box II (DRB II) can also operate as a volt/ohmmeter, but the volt/ohmmeter function cannot operate independently when the diagnostic readout box is not connected or before a test mode has been selected. On 1989 models, the volt/ohmmeter function cannot be retrieved from the ``Display Fault Code'' or ``Erase Fault Code'' tests. To use the volt/ohmmeter feature, proceed as follows:
1. Connect volt/ohmmeter test lead to the diagnostic readout box.
2. Press the Volt/Ohm key once. The diagnostic readout box will remember what test mode it was in before it switched to the volt/ohmmeter function.
3. Touch the test lead to the circuit or wire to be measured, then read the results on the readout box display.
4. Once all measurements are complete, press the Volt/Ohm key twice. This will return the readout box to the test mode it was in before it switched to the volt/ohmmeter function.