MAST AR 3C8026 - Caterpillar

Illustration 5 g00651008
Jumper wires
Turn the keyswitch to the OFF position.
Use two jumper wires to connect terminal A (coolant level low) and terminal D (coolant level normal) to terminal B (sensor common) at the harness connector. Refer to Illustration 5.
Turn the keyswitch to the ON position.
While the jumper wires are in place, access the active diagnostic code screen on Cat ET.
Verify that 111-2 diagnostic code is active. Note: Wait for 30 seconds for the activation of the diagnostic code.Expected Result:The 111-2 diagnostic code is active while the jumper wires are in place.Results:
OK - The 111-2 diagnostic code is active while the jumper wires are in place. The harness and the ECM are working correctly.Repair: Remove the jumpers. Replace the sensor and ensure that 111-2 diagnostic code disappears with the new sensor.Verify that the repair eliminates the problem. Clear all diagnostic codes.STOP
Not OK - The 111-2 diagnostic code is not active while the jumper wires are in place. Proceed to Test Step 7.Test Step 7. Check the ECM
Illustration 6 g01118015
Breakout T
(5) AP sensor/switch common
(18) Input sensor common 1
(49) Coolant level normal
(54) Coolant level low
Turn the keyswitch to the OFF position.
Fabricate two jumper wires 100 mm (4 inch) long. Crimp a Deutsch pin to both ends of each wire.
Turn the keyswitch to the ON position.
Observe the coolant level sensor status on Cat ET. Install the jumper into the breakout T in order to connect terminal 49 (coolant level normal) to terminal 5 (AP sensor/switch common).
Monitor the coolant level sensor status while the jumper is being inserted and removed. Wait for 30 seconds between the insertion of the jumper and the removal of the jumper. Waiting for 30 seconds allows the ECM to acknowledge the change. While the jumper remains in place, a diagnostic code for low coolant level should be active.
Record the result.
Leave the jumper installed in the breakout T.
Install a jumper wire from 54 coolant level low to 18 input sensor common 1 of the breakout T.
While both jumper wires are in place, access the active diagnostic code screen. Verify that a 111-2 diagnostic code is active. Wait for 30 seconds for the activation of the diagnostic code.Refer to Illustration 6.Expected Result:The coolant level sensor status behaves in the following manner:
The Coolant Level Sensor Status indicates "OK" before the jumper wire is installed between terminal 49 and terminal 5. 111-2 diagnostic code may be active.
The coolant level sensor status changes to "LOW" after the jumper wire is installed between terminal 49 and terminal 5. Also, a diagnostic code for low coolant level becomes active.The 111-2 diagnostic code is active when both jumper wires are installed.Results:
OK - The 111-2 diagnostic code is active when both jumper wires are installed. The ECM is functioning properly.Repair: Repair the harness or replace the harness, as required.Verify that the repair eliminates the problem. Clear all diagnostic codes.STOP
Not OK - The 111-2 diagnostic code is not active when both jumper wires are installed. There may be a problem with the ECM.Repair: Temporarily connect a test ECM. Ensure