BOLT-SOCKET HEAD 8T2223 - Caterpillar

System Operation Description:Use this procedure in order to troubleshoot the customer's emergency stop system or use this procedure if the diagnostic code in Table 1 is active or easily repeated.
Table 1
Diagnostic Codes Table
Code and Description Conditions which Generate this Code System Response
E264(3) Emergency Stop Activated The two inputs from the customer's emergency stop switch are in a high state. The code is logged. Fuel injection is disabled. The drive for the air shutoff is activated.
337-2 Remote Emergency Stop Switch : Erratic, Intermittent, or Incorrect The two inputs from the customer shutdown switch are in the opposite state. The code is logged. When the customer's emergency stop button is activated, the emergency stop inputs U and T to the primary ECM and the secondary ECM from the customer connector go high. The secondary ECM will recognize this change. The secondary ECM activates the output driver for the emergency shutdown system. The "Air Shutoff Switch (ASOS)" energizes the two air shutoff solenoids. The solenoids trip the air shutoff valves.Relay "R3A" and relay "R3" are energized through terminal 3 of the diode assembly. Terminal 3 of the diode assembly will energize relay "R3A" and relay "R3" for one second. The contacts of relay "R3" keep relay "R3A" and relay "R3" energized until the Engine Control Switch (ECS) is cycled to the OFF position. The contacts of relay "R3A" keep the coils of relay "R2" and relay "R2A" energized. When relays "R2" and "R2A" are energized, power is removed from the primary ECM and the secondary ECM. The primary ECM and the secondary ECM will power down. The injection signals to the injector solenoids will stop.The contact of relay "R3A" also supplies power to terminal 3 of the connector for a timer. When power is applied to terminal 3 of the connector for the timer, the timer will activate. The timer outputs 24 VDC from terminal 6 of the connector for the timer for 2.5 seconds. The 24 VDC from the timer is applied to the coil of the "ASOS" and to terminal 2 of the diode assembly. The "ASOS" energizes the two air shutoff solenoids. The solenoids trip the air shutoff valves. The 2.5 second time limit for activation of the "ASOS" prevents damage to the air shutoff solenoids. A normally open switch at the air shutoff valves will close when the air shutoff solenoid activates the air shutoff valve. The switch inputs a signal to the primary ECM and to the secondary ECM. The signal notifies the primary ECM and the secondary ECM that the air shutoff valves are closed. The primary ECM and the secondary ECM will not send injection signals to the injector solenoids until the switch inputs from the air shutoff valves indicate that the valves are open.In order to start the engine after an emergency stop condition, the ECS must be turned to the OFF position. This resets the ECM and the air shutoff timer. In addition to turning the ECS to the OFF position, the