Paccar

PACCAR MX (2004 Emissions) Fault Code: P127A EGR Pressure Difference – Data Valid but Too Low SET CONDITIONS:The PCI ECU (D420) detects that the measured EGR gas mass flow is too low for the commanded EGR valve position for more than 20 seconds. DIAGNOSTIC CONDITION:This diagnostic runs:1. When the engine speed is between 1050 and 1900 rpm and2. The engine is running at a steady load and3. The engine mode is SCR heating or SCR high efficiency mode or standard mode. CORRESPONDING OBD READINESS MONITOR:None RESET CONDITION:This DTC changes to inactive when the fault is no longer detected. REPAIR VERIFICATION:1....

PACCAR MX (2004 Emissions) Fault Code: P127B EGR Pressure Difference – Data Valid but Too High SET CONDITIONS:The PCI ECU (D420) detects that the measured EGR gas mass flow is too high for the commanded EGR valve position for more than 20 seconds. DIAGNOSTIC CONDITION:This diagnostic runs:1. When the engine speed is between 1050 and 1900 rpm and2. The engine is running at a steady load and3. The engine mode is SCR heating or SCR high efficiency mode or standard mode. CORRESPONDING OBD READINESS MONITOR:None RESET CONDITION:This DTC changes to inactive when the fault is no longer detected. REPAIR VERIFICATION:1....

PACCAR MX (2004 Emissions) Fault Code: P127C EGR Pressure Difference – Data Erratic, Intermittent, or Incorrect SET CONDITIONS:The PCI ECU (D420) detects that the measured EGR gas mass flow differs too much from the expected EGR gas mass flow for more than 40 seconds. DIAGNOSTIC CONDITION:This diagnostic runs:1. Engine speed is between 1050 and 1900 rpm and2. EGR valve position is more than 25% and3. Pressure difference between boost pressure and pressure before turbine is more than 0.25 bar [3.6 PSI] and4. The engine mode is SCR heating or SCR high efficiency mode or standard mode. CORRESPONDING OBD READINESS MONITOR:None...

PACCAR MX (2004 Emissions) Fault Code: P128E Common Rail Fuel Pressure Control – Incorrect SET CONDITIONS:The PCI ECU (D420) detects that the measured rail pressure is more than 1000 bar higher than the commanded rail pressure for more than 5 seconds. DIAGNOSTIC CONDITION:This diagnostic runs when the rail pressure operating state is: Rail discharge. RESET CONDITION:This DTC changes to inactive when the fault is no longer detected. POSSIBLE CAUSES:1. Blocked common rail pressure release valve return pipe2. Malfunction on common rail pressure release valve ADDITIONAL INFORMATION:1. The rail pressure is closed-loop controlled. A comparison is made between the rail pressure...

PACCAR MX (2004 Emissions) Fault Code: P128F Common Rail Fuel Pressure Control – Incorrect SET CONDITIONS:The PCI ECU (D420) detects that the actual rail pressure is more than 200 bar lower than the commanded rail pressure for more than 1 second. DIAGNOSTIC CONDITION:This diagnostic runs when the rail pressure operating state is: Rail discharge. RESET CONDITION:This DTC changes to inactive when the fault is no longer detected. ADDITIONAL INFORMATION:1. The rail pressure is closed-loop controlled. A comparison is made between the rail pressure commanded by the ECU and the rail pressure feedback measured by the common rail pressure sensor. 2....