With Scan Tool

Fig. 4 Self-Diagnosis System W/SST.:

A system checker, 49 H018 9A1 or equivalent scanner, can be used to diagnose troubles in the main input or output devices Fig. 4. Problems are displayed as code numbers on system checker. The control unit constantly checks for malfunction of input devices. The control unit checks for malfunction of output devices only in a 3 second period after ignition switch is turned on and test connector is grounded.

Fig. 5 Individual Switches W/SST.:

A system checker, 49 H018 9A1 or equivalent scanner, can also be used to check the operation of individual switches, through the use of the monitor lamp Fig. 5.

Fig. 22 Connecting system checker.:

1. Start engine and allow to reach normal operating temperature, then turn engine off.
2. Connect system checker to green, 6 pin check connector and negative battery cable, Fig. 22.
3. Connect jumper wire between green, 1 pin test connector and ground.
4. Turn ignition switch to On position, then check for any code number. The checker buzzer should sound for 3 seconds after ignition switch is turned to On position.
5. Start engine and check for further code numbers.
6. If code number(s) illuminates, refer to ``Testing Procedures.'' After performing repairs, cancel malfunction code numbers. Refer to ``Clearing Control Unit Memory.''