This instruction show you guide on how to solve Caterpillar C9 engine fault code 32 91-8 throttle position invalid.
The Engine Control Module (ECM) detects the following conditions:
The 8 volt supply is less than 7.5 VDC for more than one second.
·The ECM has been powered for more than three seconds.
What you need?
Caterpillar CAT ET 2026A
Cat comm3 adapter
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 refered to as either a duty ycle or a pulse width modulated signal (PWM) and this output signal is expressed as a percentage between 3 and 100 percent.
The accelerator pedal postion sensor is aached directy to the accelerator pedal assemby. The accelerator pedal position sensor requires no adustment
The accelerator pedal position sensor willproduce a duty ycle of 10 to 2 percent at low idle and 75 to 90 percent when the acelerator pedal is fuly depressed.The percent of duty cycle is translated in the ECM into an accelerator pedal position of 3 to 100 percent.
The accelerator pedal poston sensoris powered y the ECM suply yoltage (+8 VDC from conector P1-4 to terminal ' of the acelerator pedal poston sensorconnector.The accelerator pedal position sensor can be replaced separately from the pedal assembly. An incorrectly calibrated pedal assembly can not 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 and the "PTO Configuration" is programmed to one of the followingparameters:
Remote switches
Remote throttle
Note: In the cab switches configuration, the cab accelerator pedal can be used in order to control the engine rpm for the PTo operation The cab accelerator pedal can also be ignored in the "Cab Switches" PTO configuration. Programming of customer parameters is required in order to ignore the cab accelerator pedal in the Cab switches" configuration.
Probable Causes:
1) ECM Connection
2) Accelerator pedal position sensor or harness
3) Wiring between accelerator pedal position sensor and ECM
4) ECM Failure
5) Accerlerator pedal assembly
