Preparation For Testing
- Check vacuum hoses for leaks, cracks, or improper routing. Repair or replace as necessary.
- Check electrical connections. Repair any frayed or broken wires. Ensure that all connections are clean and tight.
- Turn all accessories off. Place transmission in neutral and set parking brake. Warm engine to normal operating temperature. If air cleaner must be moved, leave all vacuum hoses attached.NOTE: If vehicle will not start, see No Start Test (No. 1 for 4 and 6 Cylinder, No. 18 for V8).
- Turn ignition off. Locate Self-Test connector and insert a jumper wire between ground and Trigger sockets. Connect the positive lead of a needle-type voltmeter to vehicle battery positive terminal, and the negative lead to Self-Test output socket. Set voltmeter on 15-20 volt scale. Battery voltage may be shown.
- On 4 cylinder engines, disable canister purge system by disconnecting and plugging hose from engine side of canister purge valve. On V8 engines, remove PCV valve from valve cover.