Output Diagnostic Test Mode (Circuit Actuation Tests)
19841. Remove coil wire from distributor cap and place 1/4 inch from ground. If the coil wire is more than 1/4 inch from ground, the [1][2]power module may be damaged.
2. Disconnect air cleaner hose from throttle body, then connect diagnostic readout tool No. C-4805 to diagnostic connector.
3. Depress ATM button on readout tool and observe the following:
a. Three sparks from coil wire to ground.
b. Two AIS motor movements, one open and one closed. Listen closely for AIS operation.
c. With the ATM button still depressed, install a jumper wire between pins 2 and 3 or the gray distributor synchronizer connector. Listen for the click which indicates one set of injectors has been activated. Remove jumper wire and second set of injectors will be activated. Reconnect distributor connector.
d. One fuel pulse from injector into throttle body. ATM capability duration is 5 minutes from the time the ignition is turned on. This capability can be reinstated by cycling the ignition switch on and off three times, ending in the on position.
4. When ATM button is depressed, Code 42 is activated as the ASD relay is bypassed. After ATM operation, this code must not be used for diagnostics.
5. The ATM test verifies three categories of operation:
a. The coil firing three times indicates that the coil, logic module and [1][2]power module are operational and that the interface between modules is working.
b. The AIS motor movement indicates that the AIS motor is operational.
c. The injector fuel pulse into the throttle body indicates that the fuel pump and injector are operational and the fuel lines are intact.