Scan Tool Communication Check

1. Connect the scan tool to the Data Link Connector (DLC) located beneath the instrument panel and select the vehicle to be tested from the scan tool menu. If the scan tool does not communicate with the vehicle:
^ check that the program card is correctly installed.
^ check the connections to the vehicle.
^ check the ignition switch position.
2. If Scan tool still does not communicate with the vehicle, refer to the scan tool manual.
3. Carry out the DATA LINK DIAGNOSTIC TEST. If Scan tool responds with:
^ CKT914, CKT915 or CKT70 ALL ECUS NO RESP/NOT EQUIP, refer to Module Communications Network (Information Bus).
^ NO RESP/NOT EQUIP for Generic Electronic Module (GEM)/Central Timer Module (CTM), go to Pinpoint Test A. Test A: No Communication With the Generic Electronic Module/Central Timer Module
^ SYSTEM PASSED, retrieve and record the continuous Diagnostic Trouble Codes (DTCs), erase the continuous DTCs and carry out self-test diagnostics for the GEM/CTM. [1][2]Reading and Clearing Diagnostic Trouble Codes
4. If the DTCs retrieved are related to the concern, go to the GEM/CTM Diagnostic Trouble Code (DTC) Index to continue diagnostics. GEM/CTM Diagnostic Trouble Code (DTC) Index
5. If no DTCs related to the concern are retrieved, proceed to the Symptom Chart. Diagnosis By Symptom