Test Step 8. Use the "Injector Solenoid Test" to Check for Short Circuits in the ECM and in the Harness

317

TM 9-2320-312-24-2

Troubleshooting Section

Test Step 9. Check the Injector Harness

Repair: There is a short in the wiring harness.

for an Open Circuit Between Connector

Replace the wiring harness between the 12-pin

P300 and the Injector.

connector (P300) and the injector.

Verify that the repair eliminates the problem.

STOP.

Electrical shock hazard. The electronic unit injec-

tor system uses 90-120 volts.

Test Step 8. Use the "Injector Solenoid

Test" to Check for Short Circuits in the

ECM and in the Harness.

A. Turn the ignition key switch to the OFF position.

A strong electrical shock hazard is present if the

ignition key is not turned OFF.

B. Remove the valve cover.

Electrical shock hazard. The electronic unit injec-

tor system uses 90-120 volts.

C. Disconnect the harness from the problem injector

at the connector that is attached to the injector

A. Turn the ignition key switch to the OFF position.

solenoid. For example, if the number one injector

A strong electrical shock hazard is present if the

is the suspect injector, disconnect P301 from

ignition key is not turned OFF.

J301.

B. Disconnect ECM engine harness connector

"J2/P2" from the ECM and check for evidence

of moisture entry. Refer to Troubleshooting,

"Electrical Connectors - Inspect" for details.

C. Turn the ignition key switch to the ON position.

D. Access the "Injector Solenoid Test" on ET and

begin the test.

Note: When ECM Connector J2/P2 is disconnected,

all of the open circuit diagnostic codes for the

sensors and the open circuit diagnostic code for the

Air Inlet Heater will be active. This is normal. Clear

all diagnostic codes after completing this test step.

Expected Result:

All cylinders indicate "OPEN" when the engine

harness connector P2 is disconnected from the

ECM.

g00723455

Illustration 135

Connector for injector solenoids

Results:

D. Insert a jumper wire across the terminals of the

Yes Repair the harness between the ECM

harness connector that was removed from the

Connector P2 and the 12-pin connector (J300).

injector. For example, if the number one injector

If the harness cannot be repaired, replace the

is the suspect injector, place the jumper wire

harness. STOP.

across the terminals of "P301".

No Temporarily connect a test ECM. Repeat this

E. Turn the ignition key switch to the ON position.

test step. If the problem is resolved with the test

ECM, install the old ECM in order to verify that the

F. Access the "Injector Solenoid Test" on ET and

problem returns. If the test ECM works and the

monitor the cylinder.

old ECM does not work, replace the ECM. STOP.

Expected Result:

The status of the injector with the short in place

indicates an "OPEN".