Test Step 5. Check the Battery Voltage at the ECM

165

TM 9-2320-312-24-2

Troubleshooting Section

Expected Result:

Result 1 The original ET works on another vehicle.

Result 2 A different ET works on the original vehicle

while the engine is being tested.

Results:

Result 1 Proceed to Test Step 5.

Result 2

Repair: Send the faulty ET for repairs.

STOP.

Test Step 5. Check the Battery Voltage at

the ECM.

g00650356

Illustration 39

ECM Breakout T-connector and terminal locations for ECM P1

E. Measure the voltage between vehicle harness

A. Ensure that ET is connected to the cab data link

connector P1 terminal 70 (ignition key switch)

connector.

and terminal 65 (- battery).

B. Disconnect vehicle harness connector P1 from

Refer to Illustration 39.

ECM connector J1 and insert a breakout T.

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

Expected Result:

The voltage is between 11.0 and 13.5 VDC for a 12

D. Measure the voltage between vehicle harness

Volt system or between 22.0 and 27.0 VDC for a

connector P1 terminal 52 (unswitched +battery)

and terminal 65 (- battery).

24 Volt system.