HOSE 1P8234 - Caterpillar

System Operation Description:Use this procedure to troubleshoot the electrical system if a problem is suspected with the circuit that is for the throttle position sensor. Also use this procedure if one of the diagnostic codes in Table 2 is active or easily repeated.Note: Some of the following codes may not be applicable for certain applications.Note: Performing steps within this procedure requires the use of a multimeter capable of measuring a PWM duty cycle and frequency. Refer to Table 1 for the tools recommended for the procedure.
Table 1
Recommended Tools    
146-4080 Digital Multimeter Gp    
7X-1710 Multimeter Probe    
326-4904 Adapter Cable As    
Table 2
Diagnostic Trouble Codes    
J1939 Code     CDL Code     Code Description
(code descriptions may vary)     Comments    
29-2     774-2     Accelerator Pedal Position 2 : Erratic, Intermittent, or Incorrect     The Electronic Control Module (ECM) has detected an invalid combination of positions for the multi-position switches.
The code is logged. If equipped, the warning light will come on.
Engine RPM defaults to a predetermined safe speed. The throttle switch is ignored by the ECM until the fault is cleared and the keyswitch is cycled.    
29-3     774-3     Accelerator Pedal Position 2 : Voltage Above Normal     The ECM detects signal voltage that is not in the acceptable range.
The code is logged. The ECM flags the throttle position as invalid data and a default value is used. The engine speed is limited to high idle.    
29-4     774-4     Accelerator Pedal Position 2 : Voltage Below Normal     The ECM detects signal voltage that is not in the acceptable range.
The code is logged. The ECM flags the throttle position as invalid data and a default value is used. The engine speed is limited to high idle.    
29-8     774-8     Accelerator Pedal Position 2 : Abnormal Frequency, Pulse Width, or Period     The ECM detects an incorrect frequency on the throttle signal or an incorrect duty cycle on the throttle signal.
The code is logged. The ECM flags the throttle position as invalid data and a default value is used. The engine speed is limited to high idle.    
91-2     91-2     Accelerator Pedal Position 1 : Erratic, Intermittent, or Incorrect     The Electronic Control Module (ECM) has detected an invalid combination of positions for the multi-position switches.
The code is logged. If equipped, the warning light will come on.
Engine RPM defaults to a predetermined safe speed. The throttle switch is ignored