Component Tests and General Diagnostics

Due to pressurization of the fuel system, the following test procedure should be performed in the shortest amount of time possible.
1. Locate diagnostic connector at lefthand side firewall near the master cylinder.

Fig. 3 Bosch Motronic Electronic Engine Control System Terminal Identification:

2. Jumper a toggle switch between terminals 1 and 4, Fig. 3, of the four pin diagnostic connector.
3. Turn toggle switch On.
4. Turn ignition switch to Run position, then after 3-5 seconds turn the toggle switch off.

Fig. 5 Bosch Motronic Electronic Engine Control Periphery Code Output:

5. After approximately 2.5 seconds the check engine lamp will flash one of three codes as shown in Fig. 5. A code 91 for fuel injector test, a code 92 for idle regulator test or a code 94 for the tank emission valve or TEV test. Proper functioning of the item being tested will be indicated by a audible Tick-Tock sound.
6. To access the next periphery test, the toggle switch must be turned On for 3 to 5 seconds then turned Off.
7. To exit periphery test use one of the following steps:
a. Enter self-diagnosis as described under ``Diagnostic Fault Code Output'' in this section.
b. Turn ignition switch Off, then un-hook toggle switch from diagnostic connector.
8. If the audible Tick-Tock sound is not heard on any of the test items, refer to ``Diagnostic Code Interpretation & Testing'' for further testing.