1

1. Turn the ignition switch off.
2. Connect scan tool to the Data Link Connector (DLC).
3. Turn on the scan tool.

The scan tool turns on.

Scan Tool Inoperative

2

1. Turn the ignition switch on.
2. Using scan tool, communicate with the Powertrain Control Module (PCM) and check for Diagnostic Trouble Codes (DTCs).

Communication is established between the scan tool and the PCM.

3

Using scan tool, communicate with the Electronic Brake Traction Control Module (EBTCM) and check for DTCs.

Communication is established between the scan tool and the EBTCM.

4

Using scan tool, communicate with the instrument cluster and check for DTCs.

Communication is established between the scan tool and the instrument cluster.

5

1. If vehicle is not equipped with automatic climate control (RPO CJ2), skip to Step 6.
2. Using scan tool, communicate with the Heater-A/C Control and check for DTCs.

Communication is established between the scan tool and the Heater-A/C Control.

6

Using scan tool, communicate with the Body Control Module (BCM) and check for DTCs.

Communication is established between the scan tool and the BCM.

7

Using scan tool, communicate with the Supplemental Inflatable Restraint (SIR) system.

Communication is established between the scan tool and the SIR.

Scan Tool Does Not Communicate with UART Data Line

8

1. If vehicle is not equipped with a CD player (RPO U1S), skip to Step 9.
2. Using scan tool, communicate with the CD player.

Communication is established between the scan tool and the CD player.

Scan Tool Does Not Communicate with E and C Data Line

9

Using scan tool, communicate with the radio.

Communication is established between the scan tool and the radio.

Scan Tool Does Not Communicate with E and C Data Line

* Refer to the appropriate symptom diagnostic table for the applicable abnormal result.