Input Selection Switch Circuit

318

TM 9-2320-312-24-2

Troubleshooting Section

Note: When ECM connector J2/P2 is disconnected,

Results:

all of the open circuit diagnostic codes for the

Yes There is an open circuit in the harness.

sensors and the open circuit diagnostic code for

the air inlet heater will be active. All of the injectors

Repair the harness between the 12-pin connector

that are not jumpered will indicate an OPEN circuit

(J300) and the injector. Replace the harness if the

during the "Injector Solenoid Test". This is normal.

harness cannot be repaired. Verify that the repair

Clear all diagnostic codes after completing this test

eliminates the problem. STOP.

step.

Expected Result:

Repair: Temporarily connect a new injector to

ET displays "SHORT" for the cylinder with the

the harness. Run the "Injector Solenoid Test". If

jumper wire.

all cylinders indicate "OK", turn the keyswitch to

OFF and reconnect the old injector. If the original

Results:

injector again reads "OPEN", replace the injector.

Restore the wiring to the proper injectors. Use the

Yes Repair the harness between the 12-pin

"Injector Solenoid Test" to verify that the repair

eliminates the problem.

connector (J300) and the ECM connector P2.

Replace the harness if the harness cannot be

Do not install the valve cover until the problem is

repaired. STOP.

resolved. Clear all diagnostic codes.

No Temporarily connect a test ECM. Repeat this

test step. If the problem is resolved with the test

STOP.

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

Test Step 10. Use the "Injector Solenoid

problem returns. If the test ECM works and the

Test" to Check for Open Circuits in the

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

ECM and in the Harness.

i01858012

Input Selection Switch Circuit

Electrical shock hazard. The electronic unit injec-

- Test

tor system uses 90-120 volts.

SMCS Code: 1900-081-ZS

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

System Operation Description:

A strong electrical shock hazard is present if the

ignition key is not turned OFF.

Use this procedure under the following situation:

B. Disconnect ECM engine harness connector

Use this procedure to determine if the following

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

circuits are operating correctly:

of moisture entry. Refer to Troubleshooting,

"Electrical Connectors - Inspect" for details.

Torque limit switch

C. Connect a 70-Terminal breakout T into the ECM.

Ignore brake/clutch switch

Do not connect the engine harness connector

P2 into the breakout T.

Two-speed axle switch

D. Use a jumper wire to short between the socket

Diagnostic enable switch

of the suspect injector and the common socket

of the suspect injector.

PTO Engine RPM Set Speed Input A Switch

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

PTO Engine RPM Set Speed Input B Switch

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

The following background information is related

begin the test.

to this procedure: