Self-Diagnostic Check
The ECU has a self-diagnostic function which stores any cause for cancellation of the speed control system regardless of whether the system is normal or faulty. The system will display any circuit malfunctions as needle sweep pattern codes. See Fig 1 . The diagnostic memory is cleared if the ignition or main switch is turned off.
- Connect an analog voltmeter between Light Green speed control terminal and Black ground terminal of diagnostic harness connector, located at top of glove compartment.
- Check voltmeter reading against the display patterns. See Fig 1 . If any codes are displayed, circuit malfunction may be present. Normal state codes are codes No. 13, 14, 15 and 16. The cruise control system is normal if these codes can be reset.