SHIM 2122838 - Caterpillar

System Operation Description:Use this procedure under the following situation:The clutch pedal position switch is suspected of preventing normal operation of the cruise control, the idle set speed, or the Power Take-Off (PTO).The following switch circuits can also prevent the correct operation of the cruise control, idle set speed or PTO operation:
Service brake pedal position (switch 1)
Service brake pedal position (switch 2)
Neutral switch
Cruise control set/resume switch
Cruise control on/off switch
PTO on/off switchThese switches are described in the respective diagnostic functional tests in the Troubleshooting manual.All of the following customer programmable parameters can affect cruise control, idle set speed, and PTO operation:
"Low Cruise Control Speed Set Limit"
"High Cruise Control Speed Set Limit"
"Idle Vehicle Speed Limit"
"Cruise/Idle/PTO Switch Configuration"
"Idle/PTO Bump rpm"
"Idle/PTO rpm Ramp Rate"
"PTO Vehicle Speed Limit"The vehicle speed calibration can also affect the cruise control, the idle set speed, and the PTO if the vehicle speed calibration is incorrectly programmed. Refer to Troubleshooting, "Customer Specified Parameters".Clutch Pedal Position SwitchThe clutch pedal position switch is normally closed when the pedal is released. Depressing the clutch pedal should open the circuit. This switch is supplied and the circuitry is installed by the Original Equipment Manufacturer (OEM). The clutch pedal position switch is typically a limit switch that is activated by the pedal assembly. The clutch pedal position switch is usually adjustable. 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, or the idle set speed.The cruise control's control strategy for the Caterpillar electronic engine is similar to the strategy of the cruise controls that are installed in automobiles. The operation of the cruise control's idle setting and speed setting for the PTO is similar to the operation of the cruise control except that the idle control and the PTO control 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.Usage of Transmission Style Switches The "Transmission Style" parameter defines the configuration of the switches for the application. The Engine Control Module (ECM) can be configured to detect inputs from the following switches:
Clutch pedal position switch
Neutral switch
Service brake pedal position (switch 1)
Service brake pedal position (switch 2)Table 1 defines the combinations of switches that are necessary for the different parameter settings.
Table 1
Setting For Transmission Style Parameter Necessary Switches
Service Brake (Switch 1) Service Brake (Switch 2) Clutch Neutral
Manual Option 1 X X
Automatic Option 1 X
Automatic Option 2 X X
Automatic Option 3 X X X
Automatic Option 4 X X
Eaton Top 2 X X If the "Transmission Style" parameter is programmed to one of the following options, the input for the clutch pedal position switch is not used:
"Automatic Option 1"
"Automatic Option 2"
"Automatic Option 3"
"Automatic Option 4"The clutch pedal position switch connects