THERMOSTAT 1244835 - Caterpillar

System Operation Description:Use this procedure under the following situation:Use this procedure to determine if the Service Brake Pedal Position (Switch 2) is preventing normal operation of cruise control, fast idle, idle set speed, or PTO operation:The following switch circuits can also prevent the correct operation of the cruise control, fast idle, idle set speed or PTO operation:
Service brake pedal position (switch 1)
Neutral switch
Cruise control set/resume switch
Cruise control on/off switch
PTO on/off switch
Cruise control pause switchThe switches are described in the respective circuit tests in Troubleshooting.All of the following Customer Programmable Parameters can affect cruise control, idle set speed, fast idle, and PTO operation:
"Low Cruise Control Speed Set Limit"
"High Cruise Control Speed Set Limit"
"Idle Vehicle Speed Limit"
"Fast Idle RPM #1"
"Fast Idle RPM #2"
"Cruise/Idle/PTO Switch Configuration"
"Idle/PTO Bump rpm"
"Idle/PTO rpm Ramp Rate"
"PTO Vehicle Speed Limit"
"Cruise control pause switch"The vehicle speed calibration can also affect the cruise control, fast idle, the idle set speed, and the PTO if the vehicle speed calibration is incorrectly programmed. Refer to Troubleshooting, "Customer Specified Parameters".Service Brake Pedal Position (Switch 2)The switch for the service brake pedal position (switch 2) is normally open when the respective pedal is released. Depressing the brake pedal should close the individual circuit. This switch is OEM supplied. The service brake pedal position (switch 2) is typically a pressure switch.The following background information is related to this procedure:The kickout switch refers to the switch that is used to exit the cruise control, the PTO, fast idle, or the idle set speed.The operation of the Caterpillar electronic engine cruise control is similar to the operation of the cruise controls that are installed in automobiles. The operation of fast idle, idle, and PTO are similar to the operation of cruise except that the Idle and the PTO govern engine rpm instead of vehicle speed.Note: Idle in this procedure is an engine idle rpm above the programmed low idle rpm. Idle is set by using the Cruise Control On/Off switch and the Set/Resume switch. Refer to Troubleshooting, "PTO Switch Circuit - Test" for additional information regarding the programmable options for the Dedicated PTO.Note: Fast idle in this procedure is an engine idle rpm above the programmed low idle rpm. Fast idle is set by using a dedicated fast idle switch.Cruise Control On/Off SwitchThis switch must be ON before cruise control or controlled idle can be activated. This switch is ON when the switch is closed. When the switch is closed the following terminals are connected:
ECM connector J1/P1 terminal 59 (cruise control on/off switch)
Terminal 5 (AP sensor/switch sensor common)Note: If the vehicle is programmed to use the Dedicated PTO, the PTO on/off switch overrides the cruise control on/off switch. The PTO on/off switch overrides the cruise control on/off switch when the vehicle speed is within the range of the "PTO Vehicle Speed Limit" that is programmed.Set/Resume SwitchWith the cruise control on/off switch in the ON position and the vehicle speed within the range of the programmed Low Cruise Control Speed Set Limit and the High Cruise Control