SEAL (90 in.) 22.86 dm 5P1040 - Caterpillar

the 31-pin connector.
Turn the keyswitch to the ON position. Wait for at least 10 seconds for activation of the diagnostic codes.
Use the electronic service tool to check the "Active Diagnostic Code" screen. Check for a 3488-3 diagnostic code.
Turn the keyswitch to the OFF position.Expected Result:A 3488-3 diagnostic code for the suspect sensor is now active.Results:
A 3488-4 diagnostic code was active before removing the signal wire. A 3488-3 diagnostic code became active after removing the signal wire. - The fault is in the harness between the 40-pin connector and the 31-pin connector.Repair: Repair the faulty wiring or replace the faulty wiring.Use the electronic service tool to clear all logged diagnostic codes and verify that the repair eliminates the fault.STOP
A 3488-4 diagnostic code is still active with the signal wire removed. - The harness between the 40-pin connector and the 31-pin connector is OK. Return all wires to the original configuration. Proceed to Test Step 13.Test Step 10. Create a Short Circuit at the Valve Connector
Turn the keyswitch to the OFF position.
Disconnect the connector for the valve with the XXXX-3 diagnostic code.
Fabricate a jumper wire that is 150 mm (6 inch) long.
Insert one end of the jumper wire into the terminal for the valve position sensor signal on the harness connector for the suspect valve. Insert the other end of the jumper into the terminal for the sensor ground.
Turn the keyswitch to the ON position.
Access the "Active Diagnostic Codes" screen on the electronic service tool and check for an active XXXX-4 diagnostic code for the suspect sensor.
Remove the jumper.Results:
An XXXX-3 diagnostic code was active before the jumper was installed. An XXXX-4 diagnostic code is active when the jumper is installed. - Repair: Perform the following repair:
Reconnect the connector for the suspect valve.
Turn the keyswitch to the ON position. Use the electronic service tool to check for active diagnostic codes.
If the XXXX-3 diagnostic code returns, there is an open circuit in the valve.
Install a replacement valve. Refer to Disassembly and Assembly for the correct procedure.
Use the electronic service tool to clear all logged diagnostic codes and verify that the repair eliminates the fault.STOP
A 27-3 or 51-3 diagnostic code remains active when the jumper is installed - The valve is OK. Proceed to Test Step 13.
A 3488-3 diagnostic code remains active when the jumper is installed. - The combustion air valve is OK. Proceed to Test Step 11.Test Step 11. Create a Short Circuit at the 40-Pin Connector
Turn the keyswitch to the OFF position.
Disconnect the 40-pin connector.
Fabricate a jumper wire that is 150 mm (6 inch) long.
Insert one end of the jumper wire into pin 2 on the 40-pin connector on the harness between the engine and the CEM. Insert the other end of the jumper into pin 9 on the 40-pin connector on the harness between the engine and the CEM.
Turn the keyswitch to the ON position.
Access the "Active Diagnostic Codes" screen on the electronic service tool and check for an active 3488-4 diagnostic code.Note: While the 40-pin connector is disconnected,