HARNESS AS-CHASSIS 3142872 - Caterpillar

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Autoshift control switch (Wheel Steering)The autoshift control switch is an input to the Power Train Electronic Control Module (ECM). The autoshift control switch has two positions. The MANUAL position and the AUTO position. The switch has three connector contacts. Connector contact A connects to frame ground. Connector contact B connects to J2-37 of the Power Train ECM (manual mode). Connector contact C connects to J2-36 of the Power Train ECM (automatic mode). Two switch contacts are used for diagnosing a failure of the switch. A circuit failure is present if both of the switch contacts are open at the same time or if the two switch contacts are grounded at the same time. The valid combinations for each switch position are shown in Table 10 that follows.
Table 10
Autoshift Control Switch Status for Wheel Steering    
Switch Position     Manual 2 (J2-37)     Auto 3 (J2-36)    
Manual     Closed     Open    
Auto     Open     Closed    Note: The normally closed (N/C) circuit and normally open (N/O) circuit of the switch are used for diagnostic purposes. A circuit failure is present if the two circuits are open at the same time or if the two circuits are grounded at the same time. This fault is then shown on the display of the Caterpillar Monitoring System.ReferenceFor information on the function of the autoshift control, refer to Systems Operation, Troubleshooting, Testing and Adjusting, "Power Train Electronic Control System".ReferenceFor information on the function of the Power Train ECM, refer to Systems Operation, Troubleshooting, Testing and Adjusting, "Electronic Control Module (Power Train)".Start Switch (Key)
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Key start switchThe key start switch is an input of the Power Train Electronic Control Module (ECM). The switch connects to connector contact J2-1. The switch sends a signal to the Power Train ECM that the operator wants to start the engine. The Power Train ECM then initiates the neutral start function. The signal is open during normal operation. The switch closes to the +battery when the switch is in the START position.The switch has a connector with four contacts. Contact 1 connects to the main power relay. Contact 2 is not used. Contact 3 connects to the key start switch contact J2-1 on the Power Train ECM. Contact 4 connects to battery voltage.Note: After the switch is initially turned to the START position, the switch will not return to the START position from the ON position. The switch must be turned to the OFF position. The switch can then be turned to the START position.The Power Train ECM does not record diagnostic codes that are related with the key start switch.ReferenceFor information on the neutral start function, refer to Systems Operation, Troubleshooting, Testing and Adjusting, "Power Train Electronic Control System".ReferenceFor information on the Power Train ECM, refer to Systems Operation, Troubleshooting, Testing and Adjusting, "Electronic Control Module (Power Train)".Toggle Switch (Ride Control)
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Ride control switchThe ride control switch is an input of the Power Train Electronic Control Module (ECM). The ride control switch