PACCAR PX-8 CM2150 (2007-09) Fault Code: 452 PID: 157 SPN: 157 FMI: 4 Injector Metering Rail Number 1 Pressure Sensor Circuit – Voltage Below Normal or Shorted to Low Source. Low signal voltage detected at the rail fuel pressure sensor circuit.

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, calibrate the ECM.

This fault code will become inactive anytime the keyswitch is ON and the signal pin of the ECM is too low. This can be caused by a short circuit to ground on the +5 volt supply or signal wire. This fault will also become active if a device that is powered by the common +5-VDC power supply is shorted to ground. This fault code will become inactive any time the keyswitch is ON and the signal returns to a valid in-range voltage.

Causes for this fault code include:

1)Engine harness; the supply or signal wire is shorted to ground
2)Other components; any component connected to the common power supply is shorted to ground
3)Damaged sensor
4)Damaged ECM.

Possible repairs:

1)Replace the rail fuel pressure sensor.
2)The removal and installation of the connector may correct the fault.
3)Repair or replace the engine harness.
4)Replace the ECM.
5)Replace the OEM harness.