Expected Result -807640602

424

TM 9-2320-312-24-2

Troubleshooting Section

A. Disconnect ECM vehicle harness connector

J1/P1.

B. Insert a breakout T between the ECM vehicle

harness connectors J1 and P1.

C. Connect a test light probe to terminal 65

(-battery) and connect the other probe to terminal

52 (unswitched +battery) of the breakout T.

D. The test lamp should turn on. If the test lamp

does not turn on, either the test lamp is faulty or

the wiring to the ECM is faulty. Continue with this

step if the lamp turns on.

E. Leave the test light probe connected to terminal

52 (unswitched +battery).

F. Connect the other test light probe to terminal 29

on the breakout T.

Refer to Illustration 196.

G. Watch the voltage test lamp. Start the engine.

The lamp should turn on for a minimum of two

seconds after the engine starts. Then, the lamp

should turn off. Immediately turn the engine

off if the lamp continues to stay on. Use ET to

determine the cause of the problem.

Expected Result:

The warning lamp turns on and the warning lamp

turns off per the above description.

Results:

Yes The ECM is operating correctly. There is a

problem in the vehicle wiring or the lamp. Repair

the vehicle wiring or the lamp, as required. STOP.

No Temporarily connect a test ECM. Ensure

that the "Engine Monitoring" parameter of the test

ECM matches the "Engine Monitoring" parameter

of the suspect ECM. Check the ECM operation of

the lamp when the test ECM is installed. If the

problem is resolved with the test ECM, reconnect

the suspect ECM. If the problem returns with the

suspect ECM, replace the ECM. STOP.