For 1990-2009 cars

Step | Action | Normal Result(s) | Abnormal Result(s)*
--- | --- | --- | ---
1 |

1. Connect the scan tool to the Data Link Connector (DLC).
2. Turn the ignition switch to RUN.
3. Attempt to establish communication with the UART serial data line.

The scan tool communicates with the UART serial data line.

Scan Tool Does Not Communicate with UART Data Line

Scan Tool Does Not Communicate with UART Data Line

Scan Tool Does Not Communicate with UART Data Line

2 | Attempt to establish communication with the Class 2 serial data line. | The scan tool communicates with the Class 2 serial data line. | Scan Tool Does Not Communicate with Class 2 Data Line
3 | Attempt to establish communication with the E and C serial data line. | The scan tool communicates with the E and C serial data line. | Scan Tool Does Not Communicate with E and C Data Line
* Refer to the appropriate symptom diagnostic table for the applicable abnormal result.