Test 1A - Identifying Vehicle Equipment & System Problems

NOTE: For connector terminal identification, refer to CONNECTOR IDENTIFICATION in this article.

Connect scan tool to Data Link Connector (DLC). DLC is located under instrument cluster, right of steering column. If scan tool screen is blank, go to TEST 115A . If scan tool is not blank, go to next step.
Turn ignition on. Using a scan tool, select Body System. If scan tool does not display BUS OPERATIONAL, see the appropriate VEHICLE COMMUNICATIONS article. If scan tool displays BUS OPERATIONAL, go to next step.
Select BODY COMPUTER. If scan tool does not display BUS OPERATIONAL, see VEHICLE COMMUNICATIONS article. If scan tool displays BUS OPERATIONAL, go to next step.
If scan tool displays TURN IGNITION ON, go to TEST 112A . If scan tool does not display TURN IGNITION ON, go to next step.
If scan tool displays NO RESPONSE, go to TEST 113A . If scan tool does not display NO RESPONSE, go to next step.
Using scan tool, select INPUT/OUTPUT and read IGN RUN/START state. If scan tool displays OPEN, go to TEST 112A . If scan tool does not display OPEN, go to next step.
Using scan tool, select READ DTCS. If any fault messages are displayed, go to TEST 1B . If no fault messages are displayed, see the SYSTEM DIAGNOSTIC TEST DIRECTORY table for specific system diagnosis. When diagnosing a vehicle with many apparent failures, start at top of table and perform indicated tests. Failures may occur separately or in various combinations. After repairs, ensure failure or group of failures have been corrected.

SYSTEM DIAGNOSTIC TEST DIRECTORY ⁽¹⁾

Suspected System

Perform Test No.

Chime System

TEST 29A

Courtesy Lamp System

TEST 34A

Headlight System

TEST 43A

Illuminated Entry System

TEST 53A

Electro/Mechanical Instrument Cluster

TEST 54A

Key-In Lamp

TEST 75A

Message Center

TEST 78A

Overhead Travel Information System (OTIS)

TEST 81A

Power Door Lock System

TEST 87A

Power Door Lock System (With RKE)

TEST 95A

Windshield Wiper System

TEST 103A

⁽¹⁾

TEST 2A through TEST 24A relate to Automatic Temp. Control (ATC) system. TEST 25A through TEST 28A relate to manual A/C-heater system. For automatic or manual A/C-heater system test procedures, see the A/C-HEATER SYSTEM article. Test 116A relates to air bag system. For testing information, see AIR BAG RESTRAINT SYSTEM article.