Scan Tool Testing and Procedures

Diangostic Chart:

Schematic:

CIRCUIT DESCRIPTION
The provision for communicating with the control module is the Data Link Connector (DLC). It is usually located under the instrument panel. The DLC is used to connect to a scan tool. Some common uses of the scan tool are listed below:
^ Identifying stored Diagnostic Trouble Codes (DTCs).
^ Clearing DTCs.
^ Performing output control tests.
^ Reading serial data.

Battery power and ground is supplied for the scan tool through the DLC. The Class 2 serial data circuit to the DLC allows the PCM to communicate with the scan tool. A UART serial data line is used to communicate with other modules such as the Electronic Brake Control Module (EBCM), the Supplemental Inflatable Restraint (SIR) system and the Instrument Panel Cluster (IPC).

DIAGNOSTIC AIDS
Ensure that the correct application (model year, car line, VIN code) has been selected on the scan tool. If communication still cannot be established, try the scan tool on another vehicle to ensure that the scan tool, or cables are not the cause of the condition. An intermittent may be caused by the following:
^ Poor connection
^ Rubbed through wire insulation
^ Broken wire inside the insulation

Any circuitry, that is suspected as causing an intermittent complaint, should be thoroughly checked for the following conditions:
^ Backed out terminals.
^ Improper mating of terminals.
^ Broken locks.
^ Improperly formed or damaged terminals.
^ Poor terminals to wiring connection.
^ Physical damaged to the wiring harness.
^ Corrosion.

TEST DESCRIPTION
The number below refers to the step number on the diagnostic table:
11. The replacement PCM must be programmed and the Crankshaft Position System Variation Learn procedure must be performed.