Preliminary Information

Important
- Refer to the 88-93 Brake System Cartridge Operator's Manual for additional information about the Tech 1 and the various mode uses.

The Tech 1 has five modes to assist you in diagnosing 4WAL system malfunctions. After selecting 4WAL from the 1990-93 select system menu, the Tech 1 wilt automatically display the Select Mode menu. From here you can select one of five test modes by pressing the appropriate key:

- MODE F0: DATA LIST

This mode allows you to continuously monitor 4WAL parameters. The Tech 1 displays data parameters in pairs. The display window tells you which parameters are being displayed and the value for them.

You can program the Tech 1 to display specific pairs of parameters by following the screen commands. This allows you to monitor specific values that are not normally displayed together.

- MODE F1: FUNCTION TEST

This mode allows you to actuate the 4WAL system. The Tech 1 will send a signal to the BPMV that causes it to cycle the system. For a short period, the BPMV will cycle the valve and activate the pump motor.

- MODE F2: TROUBLE CODE

This mode allows you to access and clear DTCs. The screen will display the DTC and a brief description of what it represents.

- MODE F3: SNAPSHOT

This mode provides you with a tool to help isolate an intermittent condition. You can specify a trigger condition or manually trap the data. No matter which trigger you choose, the Tech 1 captures and stores data before and after the trigger.

- MODE F4: MISC. TESTS

This mode allows you to research the PROM ID to see which version of software is used in the BPMV, history data, history codes, and tire size calibration.