FILTER ELEMENT-CAB AIR 3276618 - Caterpillar

System Operation Description:The accelerator pedal position sensor is used to provide a throttle position signal to the Engine Control Module (ECM). Sensor output is a constant frequency signal with a pulse width that varies with the pedal position. This output signal is referred to as either a duty cycle or a pulse width modulated signal (PWM) and this output signal is expressed as a percent throttle that is between 3 and 100 percent.The accelerator pedal position sensor is attached directly to the accelerator pedal assembly. The accelerator pedal position sensor requires no adjustment.The accelerator pedal position sensor will produce a duty cycle of 10 to 22 percent at low idle and 75 to 90 percent when the accelerator pedal is fully depressed. The percent of duty cycle is translated in the ECM into an accelerator pedal position of 3 to 100 percent.The accelerator pedal position sensor is powered by the ECM supply voltage (+8 VDC) from connector P1-35 to terminal "A" of the accelerator pedal position sensor connector. The accelerator pedal position sensor can be replaced separately from the pedal assembly. An incorrectly calibrated pedal assembly cannot be adjusted. The entire pedal assembly must be replaced.If the vehicle is using the ECM dedicated PTO functions, the accelerator pedal position sensor will be ignored while the engine is in PTO mode. The ECM is in PTO mode if auxiliary input 1 is ON. This can be checked on the status screen of Caterpillar Electronic Technician (ET). Refer to Troubleshooting, "PTO Switch Circuit - Test" for testing if the PTO is being used.If "Transmision Style" is programmed to "Eaton Top 2", the operation of the accelerator position sensor can be overridden by the ECM. This will allow control of torque and control of engine speed synchronization while a shift is made in the "Top 2" mode.A second accelerator position sensor may be used for PTO purposes. The PTO accelerator sensor must be connected to the ECM connector P1/J1-31. Before the ECM will respond to the PTO accelerator, the following conditions must be met:
"PTO Configuration" must be programmed to "Remote-Throttle".
PTO "On/Off Switch" must be in the ON position.Use a 12 volt supply in order to power the PTO accelerator position sensor. The + 12 volt version of the accelerator position sensor may be used for the PTO accelerator. The + 8 volt version may be used for the cab accelerator.The ECM may not respond to the accelerator position sensor if there is an active 253-02 Check Customer or System Parameters. Refer to Troubleshooting, "ECM Memory - Test".The ECM will not respond to the PTO accelerator position sensor under the following conditions:
The PTO accelerator position sensor is above low idle.
The PTO "On/Off circuit" is switched from the OFF position to the ON position.This prevents sudden acceleration when the PTO "On/Off circuit" is turned to the ON position.
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Pedal mounted throttle position sensor
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Pedal mounted throttle position sensor for PTO
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ECM pin locationsTest Step 1. Monitor the Status for the "Accelerator Pedal