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.
Possible causes:
1)A faulty transmission shift modulator
2)An open circuit in the output device driver return wire
3)A pin-to-pin short circuit in the output device driver wire.
Possible repairs:
1)Replace the transmission shift modulator.
2)Repair or replace the OEM harness.
3)Replace the ECM.
PACCAR PX-8 CM2150 (2007-09) Fault Code: 2556 PID: SID 070 SPN: 729 FMI: 4 Intake Air Heater 1 Circuit – Voltage Below Normal or Shorted to Low Source. Low voltage detected at the intake air heater signal circuit.
PACCAR PX-8 CM2150 (2007-09) Fault Code: 2555 PID: SID 070 SPN: 729 FMI: 3 Intake Air Heater 1 Circuit – Voltage Above Normal or Shorted to High Source. High voltage detected at the intake air heater signal circuit.
PACCAR PX-8 CM2150 (2007-09) Fault Code: 2554 PID: 131 SPN: 1209 FMI: 2 Exhaust Gas Pressure – Data Erratic, Intermittent, or Incorrect. The exhaust gas pressure sensor is reading an erratic value at initial Key On.
PACCAR PX-8 CM2150 (2007-09) Fault Code: 2451 PID: SPN: 2789 FMI: 0 Turbocharger Turbine Inlet Temperature (Calculated) – Data Valid but Above Normal Operational Range – Moderately Severe Level. Turbocharger turbine inlet temperature has exceeded the engine protection limit.
PACCAR PX-8 CM2150 (2007-09) Fault Code: 2449 PID: SID 027 SPN: 641 FMI: 13 VGT Actuator Controller – Out of Calibration. The VGT has failed the automatic calibration procedure at initial key-ON.
PACCAR PX-8 CM2150 (2007-09) Fault Code: 2448 PID: SPN: 111 FMI: 1 Coolant Level – Data Valid but Below Normal Operational Range – Least Severe Level. Low engine coolant level detected.