Grand Cherokee 4WD Laredo V8-4.7L (2002)
Security Lamp/Indicator: Testing and Inspection
The diagnosis found here addresses an inoperative Vehicle Theft Security System (VTSS) indicator condition. If the problem being diagnosed is related
to indicator accuracy, be certain to confirm that the problem is with the indicator and not with an inoperative VTSS. (Refer to ELECTRICAL/VEHICLE
THEFT SECURITY - DIAGNOSIS AND TESTING - VEHICLE THEFT SECURITY SYSTEM). If no VTSS problem is found, the following
procedure will help to locate a short or open in the VTSS indicator control circuit. Refer to the appropriate wiring information.
WARNING: ON VEHICLES EQUIPPED WITH AIRBAGS, DISABLE THE AIRBAG SYSTEM BEFORE ATTEMPTING ANY STEERING
WHEEL, STEERING COLUMN, OR INSTRUMENT PANEL COMPONENT DIAGNOSIS OR SERVICE. DISCONNECT AND ISOLATE
THE BATTERY NEGATIVE (GROUND) CABLE, THEN WAIT TWO MINUTES FOR THE AIRBAG SYSTEM CAPACITOR TO
DISCHARGE BEFORE PERFORMING FURTHER DIAGNOSIS OR SERVICE. THIS IS THE ONLY SURE WAY TO DISABLE THE
AIRBAG SYSTEM. FAILURE TO TAKE THE PROPER PRE-CAUTIONS COULD RESULT IN ACCIDENTAL AIRBAG DEPLOYMENT
AND POSSIBLE PERSONAL INJURY.
1. Check the fused B(+) fuse in the Junction Block (JB). If OK, go to Step 2. If not OK, repair the shorted circuit or component and replace the
faulty fuse.
2. Check for battery voltage at the fused B(+) fuse in the JB. If OK, go to Step 3. If not OK, repair the open fused B(+) circuit between the JB and
the Power Distribution Center (PDC).
3. Disconnect and isolate the battery negative cable. Disconnect the instrument panel wire harness connector for the automatic headlamp light sensor/
VTSS indicator from the automatic headlamp light sensor/VTSS indicator pigtail wire connector. Reconnect the battery negative cable. Check for
battery voltage at the fused B(+) circuit cavity of the instrument panel wire harness connector for the automatic headlamp light sensor/VTSS
indicator. If OK, go to Step 4. If not OK, repair the open fused B(+) circuit between the VTSS indicator and the JB.
4. Disconnect and isolate the battery negative cable. Disconnect the instrument panel wire harness connector for the JB from the JB connector
receptacle. Check for continuity between the VTSS indicator driver circuit cavity of the instrument panel wire harness connector for the automatic
headlamp light sensor/VTSS indicator and a good ground. There should be no continuity. If OK, go to Step 5. If not OK, repair the shorted VTSS
indicator driver circuit between the VTSS indicator and the JB.
5. Check for continuity between the VTSS indicator driver circuit of the instrument panel wire harness connector for the automatic headlamp light
sensor/VTSS indicator and the instrument panel wire harness connector for the JB. There should be continuity. If OK, replace the faulty VTSS
indicator. If not OK, repair the open VTSS indicator driver circuit between the VTSS indicator and the JB.
