Test 2A - Blank Scan Tool Message Screen

NOTE: For connector terminal identification, see CONNECTOR IDENTIFICATION . For wiring diagrams, see appropriate article in ENGINE PERFORMANCE:

Disconnect scan tool. Using an external voltmeter, check voltage between chassis ground and Data Link Connector (DLC) terminal No. 2 (Pink wire). DLC is located under dash, left of steering column. If voltage is less than 10 volts, repair Pink wire or Red wire as necessary.
If voltage is more than 10 volts, turn ignition off. Using an external ohmmeter, check resistance between chassis ground and DLC terminal No. 4 (Black/Light Green wire). If resistance is more than 20 ohms, repair open in Black/Light Green wire.
If resistance is less than 20 ohms, try a different scan tool adapter cable. If scan tool screen is no longer blank, replace defective scan tool adapter cable.
If scan tool screen is still blank, try a different scan tool cartridge. If scan tool screen is no longer blank, replace defective scan tool cartridge. If scan tool screen is still blank, replace defective scan tool.