LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Jeep >> 1999 >> Wrangler SE, Standard >> Repair and Diagnosis >> Body & Frame >> Body, Cab Control Systems >> Body Control Computer - Tests >> System Id Test >> Identifying Vehicle Equipment & System Problems
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Identifying Vehicle Equipment & System Problems

  1. Connect scan tool to Data Link Connector (DLC). DLC is a 16-pin connector located on left side of steering column, above brake pedal. Turn ignition on. If scan tool display is not blank, go to next step. If scan tool display is blank, go to appropriate VEHICLE COMMUNICATIONS test in VEHICLE COMMUNICATIONS article.
  2. Using scan tool, select BODY SYSTEM, then BODY COMPUTER. Scan tool will perform a CCD bus test. If scan tool displays BUS OPERATIONAL, go to next step. If scan tool displays NO RESPONSE, go to appropriate VEHICLE COMMUNICATIONS test in VEHICLE COMMUNICATIONS article. If scan tool displays any other message, go to appropriate VEHICLE COMMUNICATIONS test in VEHICLE COMMUNICATIONS article.
  3. Using scan tool, select READ DTCs. If any fault messages are displayed, go to FAULT MESSAGE IDENTIFICATION  table to identify which system is affected. Go to applicable test in VTSS DIAGNOSTIC TESTS  section. If no fault messages are displayed, go to SYMPTOM TEST DIRECTORY  table for list of identified systems. Fault messages or symptoms are diagnosed using a scan tool and/or DVOM. These problems may occur separately or in various combinations. When diagnosing a system with many apparent problems, a sequence of tests may be required. After repairs, ensure problem(s) or failure(s) have been corrected by performing appropriate verification test.
FAULT MESSAGE IDENTIFICATION

Scan Tool Display Affected System (1)
ANTENNA FAILURE Vehicle Theft Security System (VTSS) (2)
EEPROM FAILURE Vehicle Theft Security System (VTSS)
INTERNAL SKIM FAILURE (2)
PCM STATUS FAILURE Vehicle Theft Security System (VTSS)
ROLLING CODE FAILURE Vehicle Theft Security System (VTSS)
SERIAL LINK EXTERNAL FAILURE Vehicle Theft Security System (VTSS)
SERIAL LINK EXTERNAL FAILURE (3) Vehicle Theft Security System (VTSS)
TRANSPONDER COMMUNICATION FAILURE Vehicle Theft Security System (VTSS)
TRANSPONDER CRC FAILURE Vehicle Theft Security System (VTSS)
TRANSPONDER ID MISMATCH Vehicle Theft Security System (VTSS)
TRANSPONDER RESPONSE MISMATCH Vehicle Theft Security System (VTSS)
VIN MISMATCH Vehicle Theft Security System (VTSS)
(1) Go to VTSS DIAGNOSTIC TESTS  .
(2) Replace SKIM and perform SKIM INTIALIZATION PROCEDURE  .
(3) Sending secret key to PCM.
SYMPTOM TEST DIRECTORY

Suspected System Proceed To
Instrument Cluster INSTRUMENT CLUSTER SYMPTOM TESTS