0128-03 Secondary Fuel Level Sensor Open Circuit (44)

128

TM 9-2320-312-24-2

Troubleshooting Section

D. Check the harness and wiring for abrasion and

B. Insert a jumper between terminal J1:49 and

pinch points from the appropriate sensor back

terminal J1:5.

to the ECM.

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

Monitor the active diagnostic code screen.

Expected Result:

All connectors, pins and sockets should be

Expected Result:

completely coupled and/or inserted and the harness

and wiring should be free of corrosion, abrasion

The "Low Coolant Level Warning" event code

or pinch points.

becomes inactive when the terminals are shorted.

Results:

OK Proceed to Test Step 3.

Yes The problem is in the harness wiring.

Not OK Repair the connectors or wiring and/or

Repair: Repair the wiring or replace the wiring,

as required.

replace the connectors or wiring. Ensure that all

of the seals are properly in place and ensure that

the connectors are completely coupled. Verify

STOP.

that the repair eliminates the problem. STOP.

No The problem is on the ECM side.

Test Step 3. Check the Coolant Level

Switch

Repair: Temporarily connect a test ECM. Ensure

that the parameters for "Engine Monitoring" and

"Coolant Level Sensor" are programmed to match

A. Connect Cat ET to the cab data link connector.

the old ECM. If the problem is resolved with the

test ECM, reconnect the suspect ECM. If the

B. Remove the connector to the coolant level switch.

problem returns with the suspect ECM, replace

the ECM.

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

Monitor the active diagnostic code screen.

STOP.

D. Short the terminals on the connector to the

coolant level switch.

i01616892

0128-03 Secondary Fuel Level

Expected Result:

Sensor Open Circuit (44)

The "Low Coolant Level Warning" code becomes

inactive when the terminals are shorted.

SMCS Code: 1408-081; 7483-038-NS

Results:

Conditions Which Generate This Code:

Yes There is a problem with the coolant level

This diagnostic code is used only by GMT-560

switch.

applications.

Repair: Replace the coolant level switch.

The Secondary Fuel Level signal voltage is above

the acceptable range for more than 10 seconds.

Ensure that the repair eliminates the problem.

System Response:

STOP.

Electronic System Response If the parameter

"Primary Fuel Tank Size" is programmed and a

diagnostic code for the primary fuel level sensor is

Repair: Reconnect the connector for the coolant

not active, the ECM will use the primary fuel level

level switch.

sensor to determine the fuel level.

Proceed to Test Step 4.

Test Step 4. Check the Harness for the

Coolant Level Switch

A. Connect Cat ET to the cab data link connector.