SENDER AS- 1947620 - Caterpillar

Table 1
Recommended Tools
146-4080 Digital Multimeter Gp
7X-1710 Multimeter Probe
326-4904 Adapter Cable As
Table 2
Diagnostic Trouble Codes
CDL Code J1939 Code Code Description
(code descriptions may vary) Comments
91-2 29-2 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.
91-3 29-3 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.
91-4 29-4 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.
91-8 29-8 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. The throttle position sensor is mounted to a pedal assembly that allows the operator to control the speed of the engine. The geometry of the pedal assembly controls both the travel of the sensor and the range of the output signal. The throttle position sensor cannot be adjusted.The output from the throttle position sensor is a PWM signal that varies with the position of the throttle pedal. The throttle position sensor produces a minimum duty cycle in the released position and a maximum duty cycle in the fully depressed position. When the pedal is released, the ECM translates the sensor output signal to a throttle position of 0 percent. When the pedal is fully depressed, the ECM translates the output signal to a throttle position of 100 percent.
Illustration 1 g03017896
Illustration 2 g01214474
P1 ECM connector
(P1-4) 8 VDC supply
(P1-5) Digital return
(P1-66) Throttle position
Table 3
Troubleshooting Test Steps Values Results
1. Check the Signal Frequency and the Duty Cycle at the Sensor
A. Turn the keyswitch to the OFF position.
B. Remove the wire from terminal location C (throttle position) on the harness side of the connector for the throttle position sensor.
C. Install a 326-4904 Adapter Cable As (3-PIN BREAKOUT) at the connector for the throttle position sensor.
D.Connect the connector for the throttle position sensor.
E. Turn the keyswitch to the ON position.
F. Measure the frequency and the duty cycle between terminal B (digital return) and terminal C (throttle position) at the 326-4904 Adapter Cable As (3-PIN BREAKOUT). Operate the throttle pedal while making the measurements.
Turn the keyswitch to the OFF position.
Remove the breakout harness. Restore the wiring for the