FREE REPAIR MANUALS & LABOR GUIDES 1982-2013 Vehicles
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Fuel Injector Electrical Circuit Diagnosis

NOTE: This test assumes that a good spark is present at the spark plugs and that there is no signal to one or more fuel injectors. Be sure that this is the case before proceeding with the following test.
1. Disconnect all the injector electrical connectors, and remove the Auto Shut Down (ASD) relay from its socket.
2. Test for continuity between the Single Board Engine Controller (SBEC) 60 way connector pins 14, 15, and 16 and ground. Locate and repair any shorts to ground between the SBEC connector and ground, and test operation.
3. Test for continuity between the DG/BK wire of all injector connectors and terminal 8 circuit A61 (DG/BK wire) of the Auto Shut Down (ASD) relay socket. Repair any open injector circuits and test operation.
4. Test for continuity between:
^ The circuit K11 WT/DB wire of injector connectors 1 and 6, and the SBEC 60 way connector pin 16 (WT/DB/ wire).
^ The circuit K12 TN wire of injector connectors 2 and 3, and the SBEC 60 way connector pin 15 (TN wire).
^ The circuit K13 YL/WT wire of injector connectors 4 and 5, and the SBEC 60 way connector pin 14 (YL/WT wire).
5. Repair any open injector circuits between the injector connectors and the SBEC, and test operation.
6. If no wiring problems were found the problem is computer related.