CYLINDER-SERVO 4N1807 - Caterpillar

Conditions Which Generate This Code:
Illustration 1 g00531536
System Schematic For Air Shutoff Relay (ASR)The GSC uses the air shutoff relay (ASR) to activate the air shutoff solenoid during a shutdown fault. The ASR is located within the relay module. The air shutoff solenoid is located within the air inlet system of the engine.The GSC activates the ASR for some active shutdown faults.Note: Whenever the GSC activates or the GSC attempts to activate the ASR, "K6" is shown on the lower display. When the ASR is not activated, "K6" is not shown.The possible cause of a CID 0446 FMI 12 is an open coil or a shorted coil of the ASR.The system responses to this diagnostic code are listed below.
If a CID 0446 FMI 12 occurs and the ASR is activated, then the system is not affected. The system is not affected because the air shutoff is already operating and shutdown mode is functioning.
If a CID 0446 FMI 12 occurs and the ASR is not activated, then there is no immediate effect on the system. The engine is able to start and the engine is able to run.
If a CID 0446 FMI 12 occurs and the ASR is not activated, then the ASR cannot energize the air shutoff solenoid when a shutdown fault occurs.This troubleshooting procedure is for an active CID 0446 FMI 12 or the troubleshooting procedure is for an inactive CID 0446 FMI 12.Test Step 1. CHECK THE STATUS OF THE DIAGNOSTIC CODE.
Turn the ECS to the OFF/RESET position and then turn the ECS to the STOP position.
Press the "Alarm Codes" key.
Observe the upper display. Check that the CID 0446 FMI 12 is active.
If the diagnostic code is not active, enter the Service Mode. View the fault log for a OP1. Check that the diagnostic code is inactive.Expected Result:A CID 0446 FMI 12 is displayed as an active diagnostic code or CID 0446 FMI 12 is displayed as an inactive diagnostic code.Results:
OK - The CID 0446 FMI 12 is active or the CID 0446 FMI 12 is inactive. Proceed to test step 2.
NOT OK - The CID 0446 FMI 12 has not occurred. The diagnostic code is not active and the diagnostic code is not inactive. Stop.Test Step 2. CHECK THE INTERNAL CABLE OF THE RELAY MODULE.Note: Only open the relay module in a dry environment. If the inspection and repair takes more than approximately twenty minutes replace the desiccant bag in the GSC housing. See Testing And Adjusting, "Relay Module - Replace".
Turn the ECS to the OFF/RESET position.
Disconnect the battery negative cable.
Temporarily, remove the relay module from the GSC. See Testing And Adjusting, "Relay Module - Replace".
Check the cable that attaches the relay module to the GSC.Expected Result:The cable should be firmly seated in the connector. The clamp should be in place. The cable should not be damaged.Results:
OK - The cable is firmly seated in the connector. The clamp is in place. The cable is not damaged. Reassemble the relay module to the GSC. Proceed to test step