Test Step 6. Insert a Jumper at the Neutral Switch

336

TM 9-2320-312-24-2

Troubleshooting Section

Test Step 6. Insert a Jumper at the Neutral

E. Install the jumper into terminal 62 (neutral switch)

Switch.

of the breakout T. Connect the other end of the

jumper to terminal 52 unswitched +battery of the

Table 181

breakout T.

Neutral Switch Input Status Table

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

Condition of Switch

Switch Status

Circuit

G. Connect ET to the cab data link connector.

Neutral switch wires are

OFF in gear

Open

H. Access the status screen.

disconnected.

Neutral switch wires are

I. While the neutral switch status is being

ON in neutral

Shorted

connected.

monitored on the status screen slowly remove

the jumper from terminal 52 unswitched +battery.

Now, slowly insert the jumper into terminal 52

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

unswitched +battery.

B. Ensure that ECM vehicle harness connector

Refer to Table 180.

J1/P1 is connected.

Expected Result:

C. Find the neutral switch in the vehicle.

The switch status changes per the information in

D. Disconnect the wires from the neutral switch

Table 180.

terminals.

Results:

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

Yes The ECM is functioning properly. Proceed

F. Connect ET to the cab data link connector.

to test step 6.

G. Access the status screen.

No The ECM is not functioning properly.

H. While the switch status is being monitored on the

Repair: Perform the following repair:

status screen slowly connect the switch wires

and slowly disconnect the switch wires.

1. Temporarily connect a test ECM.

Refer to Table 181.

2. Remove all jumpers and replace all connectors.

Expected Result:

3. Recheck the system for Active diagnostic

codes.

The switch status changes per the information in

Table 181.

4. Repeat the test step.

Results:

5. If the problem is resolved with the test ECM,

reconnect the suspect ECM.

Yes The switch is not functioning properly.

6. If the problem returns with the suspect ECM,

Repair: Perform the following repair:

replace the ECM.

Replace the faulty switch.

7. Verify that the repair eliminates the problem.

Verify that the repair eliminates the problem.

STOP.

No There is a problem in the harness between

the switch and the ECM. Proceed to Test Step 7.