BUS +/- Signals Open Or No Response From Sentry Key Immobilizer Module
NOTE:
After making any repairs, perform SENTRY KEY IMMOBILIZER SYSTEM VERIFICATION TEST
under VERIFICATION TESTS.
- Connect scan tool to Data Link Connector (DLC), under lower left side of instrument panel. Turn ignition on. Select BODY, then BODY COMPUTER. If scan tool is able to identify or communicate with Central Timer Module (CTM), go to next step. If scan tool is not able to identify or communicate with CTM, perform appropriate test relating to no communication with CTM. See DIAGNOSTIC TROUBLE CODE IDENTIFICATION table under SELF-DIAGNOSTIC SYSTEM.
- Turn ignition off. Access and disconnect Black 6-pin Sentry Key Immobilizer Module (SKIM) connector. See Figure . If necessary, see SENTRY KEY IMMOBILIZER MODULE under REMOVAL & INSTALLATION. Using DVOM, measure resistance between ground and Black 6-pin SKIM connector terminal No. 5 (Black/White wire). See Fig 1 . If resistance is 5 ohms or less, go to next step. If resistance is more than 5 ohms, repair open or high resistance in Black/White wire between Black 6-pin SKIM connector terminal No. 5 and ground. See GROUND DISTRIBUTION article in WIRING DIAGRAMS. Repair as necessary.
- Turn ignition on. Using test light connected to ground, probe Black 6-pin SKIM connector terminal No. 4 (Light Green/Black wire). If test light illuminates, go to next step. If test light does not illuminate, check fuse No. 10 (10-amp) in instrument panel junction block. If fuse is okay, repair open in Light Green/Black wire between Black 6-pin SKIM connector terminal No. 4 and fuse No. 10 in instrument panel junction block. If fuse is blown, check for short to ground in Light Green/Black wire between Black 6-pin SKIM connector terminal No. 4 and fuse No. 10 in instrument panel junction block. Repair as necessary.
- Using test light connected to ground, probe Black 6-pin SKIM connector terminal No. 6 (Pink wire). If test light illuminates, go to next step. If test light does not illuminate, check fuse No. 1 (15-amp) in instrument panel junction block. If fuse is okay, repair open in Pink wire between Black 6-pin SKIM connector terminal No. 6 and fuse No. 1 in instrument panel junction block. If fuse is blown, check for short to ground in Pink wire between Black 6-pin SKIM connector terminal No. 6 and fuse No. 1 in instrument panel junction block. Repair as necessary.
- Ensure there is PCI BUS communication with other modules before proceeding. If there is no PCI BUS communication with other modules, perform appropriate test relating to no communication. See DIAGNOSTIC TROUBLE CODE IDENTIFICATION table under SELF-DIAGNOSTIC SYSTEM. Connect Scope Input Cable (CH7058) to channel one connector on scan tool. Connect Cable-To-Probe Adapter (CH7062) and Black and Red test probes to scope input cable. Connect Black test probe to ground. Connect Red test probe to PCI BUS circuit at Black 6-pin SKIM connector terminal No. 2 (Violet/Yellow wire).
- Using scan tool, select PEP MODULE TOOLS, LAB SCOPE, LIVE DATA. Select 12 VOLT SQUARE WAVE. Press F2 for SCOPE. Press F2 and use DOWN arrow to set voltage scale to 20 volts. Press F2 again when complete. Turn ignition on. If reading on lab scope toggles between zero and 7.5 volts, replace SKIM. See SENTRY KEY IMMOBILIZER MODULE under REMOVAL & INSTALLATION. If reading on lab scope does not toggle between zero and 7.5 volts, repair open in PCI BUS circuit (Violet/Yellow wire).