GEAR-IDLER 2W0500 - Caterpillar

Use this procedure if the digital throttle position sensor is suspected of incorrect operation. This procedure also covers the following diagnostic codes:
Table 1
Diagnostic Trouble Codes for the Digital Throttles
J1939 Code CDL Code Code Description
(code descriptions may vary) Comments
29-3 774-3 Accelerator Pedal Position 2 : Voltage Above Normal The Electronic Control Module (ECM) detects the following conditions:
The ECM has been powered for 3 seconds.
Diagnostic code 168-4 is not active.
There are no active 678 or 41 codes.
The setting for the upper diagnostic limit has been exceeded for one second.
If equipped, the warning lamp will come on. The diagnostic code will be logged.
29-4 774-4 Accelerator Pedal Position 2 : Voltage Below Normal The ECM detects the following conditions:
The ECM has been powered for 3 seconds.
Diagnostic code 168-4 is not active.
There are no active 678 or 41 codes.
The setting for the lower diagnostic limit has been exceeded for one second.
If equipped, the warning lamp will come on. The diagnostic code will be logged.
29-8 774-8 Accelerator Pedal Position 2 : Abnormal Frequency, Pulse Width or Period The ECM detects the following conditions:
The signal frequency from the digital throttle position sensor is equal to 0% or 100% for more than 2 seconds.
The ECM has been powered for at least 3 seconds.
Diagnostic codes 29-3, 774-3, 29-4, and 774-4 are not active.
There are no active 678 or 41 codes.
The ECM sets the Throttle Position to "0%".
If equipped, the warning lamp will come on. The diagnostic code will be logged if the engine is running. The diagnostic code will not be logged if the engine is cranking.
91-3 91-3 Accelerator Pedal Position 1 : Voltage Above Normal The Electronic Control Module (ECM) detects the following conditions:
The ECM has been powered for 3 seconds.
Diagnostic code 168-4 is not active.
There are no active 678 or 41 codes.
The setting for the upper diagnostic limit has been exceeded for one second.
If equipped, the warning lamp will come on. The diagnostic code will be logged.
91-4 91-4 Accelerator Pedal Position 1 : Voltage Below Normal The ECM detects the following conditions:
The ECM has been powered for 3 seconds.
Diagnostic code 168-4 is not active.
There are no active 678 or 41 codes.
The setting for the lower diagnostic limit has been exceeded for one second.
If equipped, the warning lamp will come on. The diagnostic code will be logged.
91-8 91-8 Accelerator Pedal Position 1 : Abnormal Frequency, Pulse Width or Period The ECM detects the following conditions:
The signal frequency from the digital throttle position sensor is equal to 0% or 100% for more than 2 seconds.
The ECM has been powered for at least 3 seconds.
Diagnostic codes 91-3 and 91-4 are not active.
There are no active 678 or 41 codes.
The ECM sets the Throttle Position to "0%".
If equipped, the warning lamp will come on. The diagnostic code will be logged if the engine is running. The diagnostic code will not be logged if the engine is cranking.
Follow the troubleshooting procedure to identify the root cause of the fault. If a fault occurs with the primary throttle, the engine will