Switch Tests

The engine must be running and code .7.0 must be displayed on the "Data Center" panel before the switch tests can begin. To start the switch tests sequence depress and release the brake pedal. The switch tests begin as the display switches from code .7.0 to code E.7.1 (if the display doesn't advanced to code E.7.1, refer to the diagnosis chart code E.7.1, because the ECM is not processing the brake signal). As each code is displayed, the associated switch must be cycled within 10 seconds or the code will be recorded in the ECM's memory as a failure. After the ECM recognizes a test as passing or after the 10 second time-out elapse without the proper cycling being recognized, the display automatically advances to the next switch test code.

The switch tests sequence is performed as follows:

1. With code E.7.1 displayed, depress and release the brake pedal again to test the Cruise Control/VCC brake circuit.

2. With code E.7.2 displayed, depress the throttle from the idle position to an open throttle position and then slowly release the throttle. While this action is being performed, the ECM checks the throttle switch for proper operation.

3. With code E.7.4 displayed and the brakes applied, shift the transmission lever into reverse and then neutral. This action checks the operation of the park neutral switch. If the automatic parking brake is depressed, it will be released when the lever is placed in reverse.

4. With code E.7.5 displayed, switch the Cruise Control instrument panel switch from on to off and back to on to check the operation of this switch.

5. With code E.7.6 displayed and with the cruise instrument panel switch in the on position, depress and release the set/coast button to check the operation of this switch.

6. With code E.7.7 displayed and with the cruise instrument panel switch in the on position, depress and release the resume acceleration switch to check the operation of this switch.

7. With code E.7.8 displayed and the engine running, turn wheels from straight ahead to full right or left and then return to straight ahead. While this action is being performed, the ECM checks the power steering pressure switch for proper operation.

8. When the switch tests are completed, the ECM will now go back and display the switch codes which did not test properly. Each code which did not pass will be displayed beginning with the lowest number. The codes will not disappear until the affected switch circuit has been repaired and retested or switch test diagnostics are exited. Refer to the appropriate diagnosis chart for each failed switch test.

9. After the switch tests are completed and all circuits pass, the ECC panel displays "E.0.0" and then returns to code .7.0. "E.0.0" indicates that all of the switch circuits are operating properly.

NOTE: On cars without Cruise Control, codes E.7.5, E.7.6 and E.7.7 will be displayed but cannot be performed during the switch tests. When these codes are displayed during the switch tests, allow each code to reach its 10 second time out. After this time out has elapsed, the display will advance to the next code. Allow codes E.7.5, E.7.6 and E.7.7 to time out (30 seconds). Since these codes will be recorded as failures in the switch tests sequence, a display of E.0.0 will never be observed at the completion of the tests (see Step #9). To confirm proper operation of the remaining switch, code E.7.8 must be observed as having advanced within the 10 second time out. If the code cannot be advanced within its time out, it should be considered a failed test.