GUARD 7M5338 - 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 Comments
29-3
Accelerator Pedal Position #2 : Voltage Above Normal The Electronic Control Module (ECM) detects signal voltage that is not in the acceptable range.
The ECM flags the throttle position as invalid data and a default value is used. The engine speed is limited to high idle.
The code is logged.
29-4
Accelerator Pedal Position #2 : Voltage Below Normal The ECM detects signal voltage that is not in the acceptable range.
The ECM flags the throttle position as invalid data and a default value is used. The engine speed is limited to high idle.
The code is logged.
91-3
Accelerator Pedal Position #1 : Voltage Above Normal The ECM detects signal voltage that is not in the acceptable range.
The ECM flags the throttle position as invalid data and a default value is used. The engine speed is limited to high idle.
The code is logged.
91-4
Accelerator Pedal Position #1 : Voltage Below Normal The ECM detects signal voltage that is not in the acceptable range.
The ECM flags the throttle position as invalid data and a default value is used. The engine speed is limited to high idle.
The code is logged.
91-8
Accelerator Pedal Position #1 : Abnormal Frequency, Pulse Width, or Period The ECM detects signal voltage that is not in the acceptable range.
The ECM flags the throttle position as invalid data and a default value is used. The engine speed is limited to high idle.
The code is logged.
974-5
Remote Accelerator Pedal Position : Current Below Normal The code is logged.
974-6
Remote Accelerator Pedal Position : Current Above Normal The code is logged. For this troubleshooting procedure, the desired speed input configuration parameter can be set to 4 mA to 20 mA input, PWM input, or 0 V to 5 V input. The Electronic Control Module (ECM) will only monitor the status of the input signal for the PWM and 0 V to 5 V desired speed inputs. The ECM does not supply the power and ground for the PWM or 0 V to 5 V speed control circuits.If using the Operator Control Panel (OCP) 0 V to 5 V analog output or the PWM speed control feature, then the OCP will monitor the status of those outputs in relation to power and ground circuit health. If an external speed control source device is used, refer to that devices troubleshooting procedure. If using the OCP CAN desired speed input, refer to troubleshooting procedure Troubleshooting, Data Link-Test.The value of the current, frequency, or voltage corresponds to a range of desired engine speeds between minimum high idle and maximum high idle. The "Minimum Engine High Idle Speed" and the "Maximum Engine High Idle Speed" are set with the "Service/Configuration" screen of Cat® Electronic Technician (ET). For more information, refer to Troubleshooting, Configuration Parameters.When the idle/rated speed switch is in the RATED position, a current value of 4.0 mA, 5 percent duty cycle,