Dakota 4WD V6-239 3.9L VIN X FI (1989)
Fuel Injector: Testing and Inspection
NOTE: The fuel system wiring diagrams should be used in conjunction with the following test to correctly diagnose the problem.
1.
Turn the ignition switch to the CRANK position.
2.
Using a logic probe or a noid light, probe the injector electrical connectors and check that the injector is receiving a signal from the SMEC.
3.
If there is no signal at either injector electrical connector, disconnect the 60-Way SMEC electrical connector and the injector electrical connectors.
Connect an ohmmeter between the VT/YL wire of the injector connector of injector #1 and pin No. 33 of the SMEC connector, and check for
continuity. Connect an ohmmeter between the GY/WT wire of the injector connector of injector #2 and pin No. 32 of the SMEC connector, and
check for continuity. If there is no continuity in either circuit, fix open in wire. If there is continuity in both circuits, go to step 4.
4.
Connect a voltmeter to the DG/BK wire of each injector connector, and turn the ignition switch to RUN position. Voltage should be at the DG/BK
wire of both injector electrical connectors for approximately 2 to 3 seconds.
a.
If there is less than 12 volts at either injector connector, connect a voltmeter to the solid DG/BK wire (terminal No. 87) of the Auto Shutdown
(ASD) relay and check that there is 12 volts. If there is 12 volts at terminal No. 87, repair the wire between the Auto Shutdown (ASD) relay
and the injector connector. If there is less than 12 volts at terminal No. 87 of the ASD relay, test the Auto Shutdown (ASD) relay.
b.
If there is 12 volts at the injector connector, and there is continuity between the VT/YL wire and the GY/WT wire of the injector connectors
and pin No. 32 and 33 of the SMEC connector, the problem is computer related.
