CYLINDER PACK AS 0R4635 - Caterpillar

Use this procedure in order to troubleshoot the emergency stop system. Or, use this procedure if the following diagnostic code is active or easily repeated.
Table 1
Diagnostic Codes Table
J1939 Code and Description Conditions which Generate this Code System Response
970-2
Engine Auxiliary Engine Shutdown Switch : Erratic, Intermittent, or Incorrect The two inputs from the emergency stop switch are in the opposite state. The code is logged. The Electronic Control Module (ECM) receives two signals from the emergency stop switch. The signals allow the ECM to determine the status of the emergency stop switch. The ECM will shut down the engine when both of the signals are open. When both of the signals are connected to the −Battery the emergency stop switch is not active, and the engine will run. If two different signals are detected during the powerup, the ECM will determine that one of the signals is incorrect. A diagnostic code will be logged and a diagnostic code will remain active. The engine will continue to run when the ECM detects two different signals. If both of the signals are open, the engine will stop.The customer can install multiple emergency stop switches. When the Engine Control Switch (ECS) is turned to the ON position, the engine will begin the sequence for start-up.When the emergency stop switch is activated, the ECM will stop firing the injectors. The engine will stop. When an emergency stop is received by the ECM, the ECM will activate the output for the solenoid valve that controls the air shutoff valve. When the solenoid valve activates, the air shutoff valve closes removing the intake air to the engine. Manually open the air shutoff valve in order to start the engine.Note: The air shutoff is optional. Set the programmable parameter with Caterpillar Electronic Technician (ET) in order to enable the air shutoff. The 970-31 Engine Auxiliary Engine Shutdown Switch event code will be set when the remote emergency stop switch is activated. This event will prevent engine operation. Electrical power to the ECM must be removed for three seconds in order to clear this event.
Illustration 1 g03382536
Emergency stop schematic
Illustration 2 g03393097
P1 ECM connector
(P1-5) Digital return
(P1-19) Air shutoff relay
(P1-23) E-Stop 1
(P1-40) Start/Run/Stop 1
(P1-52) +Battery
(P1-53) +Battery
(P1-54) Start/Run/Stop 2
(P1-55) +Battery (ECM)
(P1-56) E-Stop 2
(P1-61) −Battery
(P1-62) Air shutoff feedback
(P1-63) −Battery
(P1-70) Keyswitch
Illustration 3 g03393098
Customer connector
(Terminal 01) +Battery
(Terminal 02) +Battery
(Terminal 04) Air shutoff
(Terminal 09) Digital return
(Terminal 16) E-Stop 1
(Terminal 17) E-Stop2
(Terminal 23) Start/Run/Stop 1
(Terminal 24) Start/Run/Stop 2
(Terminal 27) Keyswitch
(Terminal 34) −Battery
(Terminal 35) −Battery
Table 2
Troubleshooting Test Steps Values Results
1. Inspect the Electrical Connectors and the Wiring
A. Turn the main disconnect switch to the OFF position.
B. Verify that the air shutoff mechanisms are set to the OPEN position.
C. Thoroughly inspect the ECM connectors. Also, inspect the connectors at the air shutoff mechanism that are for the solenoids. Also, inspect the switches for the air shutoff. Refer to Troubleshooting, "Electrical Connectors - Inspect"
D. Perform a 45 N (10 lb) pull test on each of the wires that are associated with the circuit for the air shutoff system.
E. Check the allen