Test 108A - Repairing Scan Tool Blank Screen
NOTE:
For connector terminal identification, see CONNECTOR IDENTIFICATION
. For appropriate wiring diagram, see WIRING DIAGRAMS
section at the end of this article. Perform TEST VER-1B after each repair.
CAUTION:
Always turn ignition off prior to disconnecting any module connector.
- Turn ignition off. Disconnect scan tool from Data Link Connector (DLC). Using an external voltmeter, check voltage between DLC terminal No. 3 (Red wire) and chassis ground. If voltage is less than 10 volts, repair Red wire from DLC to fuse No. 3 as necessary. If voltage is more than 10 volts, go to next step.
- Using an external ohmmeter, check resistance between DLC terminal No. 8 (Black/Light Green wire) and chassis ground. If resistance is more than 20 ohms, repair open Black/Light Green wire. If resistance is less than 20 ohms, go to next step.
- Substitute a known good scan tool cable. If scan tool display is not blank, replace defective scan tool cable. If scan tool display is blank, and Diagnostic Readout Box (DRB) III is being used, replace DRB III. If scan tool other than DRB III is being used, go to next step.
- Substitute a known good scan tool cartridge. If scan tool display is not blank, replace defective scan tool cartridge. If scan tool display is blank, replace scan tool.