SEAL-O-RING 1P8116 - Caterpillar

Use this procedure to troubleshoot a problem with the throttle position sensor. Also, use this procedure if one of the following diagnostic codes is active or easily repeated.
Table 1
J1939 Code and Description CDL Code and Description Comments
91-3
Accelerator Pedal Position #1 : Voltage Above Normal 91-3
Throttle Position Sensor : Voltage Above Normal The Electronic Control Module (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
Accelerator Pedal Position #1 : Voltage Below Normal 91-4
Throttle Position Sensor : 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. Note: Performing steps within this procedure requires the use of a multimeter capable of measuring a PWM duty cycle and frequency. Refer to Table 2 for the tools recommended for the procedure.
Table 2
Recommended Tools
146-4080 Digital Multimeter Gp
7X-1710 Multimeter Probe
326-4904 Adapter Cable As The Electronic Control Module (ECM) can be configured to receive two different types of throttle signals for the engine throttle control:
CAN Input - A J1939 signal is received via the CAN data link.
PWM - The Pulse Width Modulated signal (PWM) must be received via terminal P1-66 at the ECM connector. If direct fuel control mode is used on the engine, the PWM signal must be received via terminal P1-66 at the ECM connector.The ECM also allows a primary throttle and a secondary throttle to be configured for the engine if direct fuel control mode is disabled. The type of signal that will be used for the primary throttle is configured by setting the "Desired Speed Input Configuration" parameter. The type of signal that will be used for the secondary throttle is configured by setting the "Secondary Desired Speed Input Configuration" parameter. Configuring both of these parameters to the same setting will invalidate the setting for the secondary throttle.The ECM will utilize the signal that is defined as the primary throttle as long as a valid signal is available from the expected source. If the signal from the primary throttle becomes unavailable, the ECM will use the signal that is defined as the secondary throttle. If both throttle signals become unavailable, the ECM uses the rated speed of the engine as the setpoint for the desired engine speed.For using an electronic external governor for engine control, the "Direct Fuel Control Mode" parameter must be enabled. The ECM input at P1-66 must be used for direct fuel control of the engine. Refer to Troubleshooting, "Direct Fuel Control Mode - Test" for additional information.
Illustration 1 g03889309
Table 3
Troubleshooting Test Steps Values Results
1. Inspect the Electrical Connectors and the Wiring
A. Turn the main disconnect switch to the OFF position.
B. Thoroughly inspect the connectors. Refer to Troubleshooting, "Electrical Connectors-Inspect" for additional information.
C. Perform a 45 N (10 lb) pull