PACCAR PX-8 CM2150 (2007-09) Fault Code: 1242 PID: 91 SPN: 91 FMI: 2 Accelerator Pedal or Lever Position Sensor 1 and 2 – Data Erratic, Intermittent, or Incorrect. Accelerator position sensor number 1 and number 2 are reading different values.

Verify the electronic control module (ECM) calibration is correct. Check the calibration revision history found on QuickServe® Online for applicable fixes to the calibration stored in the ECM. If necessary, recalibrate the ECM.

Newer engines use two throttle position sensors to determine the throttle position. Older throttle pedals used a single throttle position sensor and an idle validation switch. If Fault Codes 132 and 1241 are active when the accelerator pedal is in the idle position and Fault Code 132 goes inactive and Fault Code 1239 goes active when the throttle is depressed, the incorrect throttle pedal has been installed in the vehicle. A throttle pedal with two acceleration position sensors should be installed.

This fault code becomes active when the accelerator position sensor number 1 and accelerator position sensor number 2 are not reading the same value.

Possible causes:

1)Damaged accelerator pedal position sensor number 1 or damaged accelerator pedal position sensor number 2.
2)Damaged accelerator pedal position sensor number 1 and damaged accelerator pedal position sensor number 2 signal wires are shorted together.

Possible repairs:

1)Replace the accelerator pedal.
2)The removal and installation of the connector may correct the problem.
3)Repair or replace the OEM harness.
4)Replace the ECM.