Turbo Overboost Testing

Figure 3:

Test the turbo overboost audible warning system by using the following procedure.

1. Lower the driver's side door window.

2. Be sure that both doors are closed.

3. Turn the ignition key to the ON position (Not START).

4. Wait until the audible warning system stops sounding.

5. Disconnect the overboost vacuum switch wiring connector, Figure 3.

6. Bridge the wiring connector terminals together and listen for the audible warning in the passenger compartment.
7. If the audible warning system is OK, reconnect the turbo overboost vacuum switch wiring.

C262 & C263 REPLACEMENT

If the audible warning system does not operate, test diodes (C262 & C263) by using the following procedure.

1. Turn the ignition key to OFF.

2. Remove the center console forward trim panel, RH side.

3. Detach the two diodes from the wiring harness and test them as previously described with an ohmmeter.

4. Replace any diodes which are defective.

5. Tape the diodes to the wiring harness to prevent rattles.

6. Check the overboost audible warning system.

7. Connect the turbo overboost switch wiring.

8. Install the center console forward trim panel.