DESCRIPTION & OPERATION
| WARNING | Vehicles are equipped with air bag supplemental restraint system. Before attempting any repairs involving steering column, instrument panel or related components, see SERVICE PRECAUTIONS and DISABLING & ACTIVATING AIR BAG SYSTEM in AIR BAG RESTRAINTS article under RESTRAINTS. |
| CAUTION | When battery is disconnected, vehicle computer and memory systems may lose memory data. Driveability problems may exist until computer systems have completed a relearn cycle. See COMPUTER RELEARN PROCEDURES article in GENERAL INFORMATION before disconnecting battery. |
A scan tool can be connected to the Data Link Connector (DLC), allowing the scan tool to communicate with the Vehicle Control Module (VCM), Passlock/Electronic Variable Orifice (P/EVO) module, inflatable restraint Sensing and Diagnostic Module (SDM) and Electronic Brake Control Module (EBCM).
Test Description
The steps listed below refer to numbers on the following diagnostic chart, no information is missing.
- 1. This step is to determine whether the scan tool can be powered up
- 2. This step is to determine whether the scan tool can be powered up
- 3. This step is to determine if the scan tool can communicate with the UART Data Line, specifically within the Supplemental Inflation Restraint System
| Step | Action | Normal Result(s) | Abnormal Result(s)* |
|---|---|---|---|
| 1 | With scan tool connected make contact with any of the modules applicable to the vehicle | Scan Tools main menu. | * Blank Screen * No power to the scan tool Refer to SCAN TOOL INOPERATIVE |
| 2 | Select Diagnostics Circuit Check, Class 2 DTC Check from the scan tools menu. | No DTC's found. | The module(s) listed will have DTC's present. * U1016. Refer to SCAN TOOL WILL NOT COMMUNICATE WITH CLASS 2 DATA LINE * U1255. Refer to SCAN TOOL WILL NOT COMMUNICATE WITH CLASS 2 DATA LINE * No Communication with the vehicle, or Diagnostic Link Connector. Refer to SCAN TOOL WILL NOT COMMUNICATE WITH CLASS 2 DATA LINE |
| 3 | 1. Select Body Diagnostics from the scan tools menu. 2. Select SIR UART Data Line information. 3. Access DTC's using the scan tool. | No DTC's found. | No communication with the vehicle, or Diagnostic Link Connector. Refer to SCAN TOOL WILL NOT COMMUNICATE WITH CLASS 1 (UART) DATA LINE |
| * Refer to the appropriate symptom diagnostic table for the applicable abnormal result. | |||
DIAGNOSTIC SYSTEM CHECK - DATA LINK COMMUNICATIONS