PACCAR PX-9 CM2350 (2013-17) Fault Code:148 PID:91 SPN:91 FMI:0 Accelerator Pedal or Lever Position Sensor 1 – Data Valid But Above Normal Operating Range – Most Severe Level

Reason:
Accelerator Pedal or Lever Position Sensor 1 – Data Valid But Above Normal Operating Range – Most Severe Level. A frequency of more than 1500 Hz has been detected at the frequency throttle input to the ECM.

Effect:
Engine will only idle.

Circuit Description:
This type of throttle interface is designed to accept a variable frequency signal as the throttle signal. An electronic component generates a square wave logic-level signal in which the frequency of the signal corresponds to a throttle command. The frequency values are established by the calibration in the engine control module (ECM).

Component Location:
Throttle location varies with each OEM. Refer to the OEM service manual.

Conditions for Running the Diagnostics:
This diagnostic runs continuously when the keyswitch is in the ON position and the engine is running.

Conditions for Setting the Fault Codes:
The Engine Control Module (ECM) detected the accelerator pedal or lever position and idle validation switch did not match.

Action Taken When the Fault Code is Active:
1) The ECM illuminates the red STOP ENGINE lamp immediately after the diagnostic runs and fails.
2) The engine will only idle.

Conditions for Clearing the Fault Code:
1) To validate the repair, perform a key cycle, start the engine and let it idle for 1 minute.
2) The ECM will turn off the red STOP ENGINE lamp immediately after the diagnostic runs and passes.
3) The fault code status displayed by INSITE™ electronic service tool will change to INACTIVE immediately after the diagnostic runs and passes.
4) The Reset All Faults command in INSITE™ electronic service tool can be used to clear active and inactive faults.

Shop Talk:
N/A

Possible Causes:
1) Malfunctioning frequency throttle.
2) Signal circuit shorted to a voltage source