Electrical Circuit Test

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.

1. Start engine. If engine does not start, see step 4.
2. Listen to injectors. Use a screwdriver or stethoscope to amplify the sound. A "clicking" should be heard if the injectors are operating properly. If an injector is inoperative, proceed with step 4.
3. If injectors are operating, but engine runs rough, disconnect/connect injector wires one at a time.
a. If engine speed drops of considerably when wire is disconnected, injector is operating correctly.
b. If engine speed drops only slightly or not at all, proceed with next step.

Color Code Legend:

Checking ECU Ground Connections:

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

Removing ECU Connector:

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

Removing Protective Cover:

8. 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.

Bridging Suppressor Relay:

9. Check fuel injectors by removing suppressor relay located in front of driver side strut tower.
10. Bridge terminals 2 (blue-yellow) and 3 (green-red) of suppressor relay socket.

Checking Fuel Injectors:

11. Connect an ohmmeter between ECU connector pin 9 and 18.

Reading: 4 ohms

If reading is correct, system is in good working order, continue with step 14. If reading is incorrect, continue with next steps.
12. If reading is higher, current is not going through the injectors.
If resistance is:

Approx. 2.9 ohms = fault in one injector or its wiring.
Approx. 4.4 ohms = fault in two injectors or their wiring.
Approx. 8.5 ohms = fault in three injectors or their wiring.

Checking Resistance At Injectors:

13. Check each individual injector separately by disconnecting the injector connector. Connect the ohmmeter to the two connectors on the injector.

Reading: 2 ohms

If not, replace injector and retest.
14. Reinstall suppressor relay.

Assemble Connector:

15. Disconnect the test equipment. Reconnect the ECU and all other connectors, install the kick panel and glove compartment.