Fuel Injection

TESTING PROCEDURE:

NOTE: While trouble shooting, always check the wiring, fuses and connectors for good condition and routing. Also check ground locations for good connection. Use the wiring diagrams found in SCHEMATIC DIAGRAMS to supplement your testing efforts.

Color Code Legend:

Checking ECU Ground Connections:

1. Turn ignition OFF.
2. Access fuel injection ECU by removing the passenger side kick panel and glove compartment.
3. Check fuel injection ECU ground connections. They should make good contact and fit tight.

Removing ECU Connector:

4. Remove the ECU connector by pressing up the latch and folding out the wire cluster.

Removing Protective Cover:

5. Remove connector protective sleeve.
CAUTION: ^ Never check connections from the front. Connectors can get damaged and worsen the problem.
^ Check connections through the holes in the connector.
^ Connection pin numbers are printed on the connector side.

Checking Pin 18:

6. Turn ignition ON.
7. Connect a voltmeter between pin 18 at ECU connector and ground (checking ignition switch).

Reading: approx. 12 volts

8. If not, check wiring, fuses #1, #12 and #13 (located behind center console ash tray) and connectors. If no fault found, replace ignition switch and retest.
9. Crank starter motor.

Reading: no less than 10.5 volts

If not, check wiring and connectors. If no fault found, replace ignition switch and retest.
10. Turn ignition OFF.

Checking Ground Connections:

11. Check that two wires are connected to pin 5 (one ground wire and the oxygen sensor shielding wire).
12. Connect an ohmmeter between pin 5 and ground.

Resistance: 0 ohm

13. If not, check wiring and fix as necessary.
14. Then connect the ohmmeter between pin 11 and ground.

Resistance: 0 ohm

15. If not, check wiring and fix as necessary.
16. Then connect the ohmmeter between pin 19 and ground.

Resistance: 0 ohm

17. If not, check wiring and fix as necessary.
18. Then connect the ohmmeter between pin 25 and ground.

Resistance: 0 ohm

19. If not, check wiring and fix as necessary.

Checking Test Points:

20. To check that the test points are not grounded, connect the ohmmeter between pin 12 (constant idle speed system test point) and ground.

Resistance: infinite

21. If not, check wiring and fix as necessary.
22. Connect the ohmmeter between pin 22 (oxygen sensor system test point) and ground.

Resistance: infinite

23. If not, check wiring and fix as necessary.

Assemble Connector:

24. Disconnect the test equipment. Reconnect the ECU and all other connectors, install the kick panel and glove compartment.
25. The previous tests eliminate any power supply or ECU ground problems. If an ECU fault is suspected, see next step.
26. To find the problem, you can test every input and output device. If no faults are found and all wiring, connectors, fuses and the battery are in good condition, replace and retest ECU with known good unit.