Paccar

PACCAR MX (2004 Emissions) Fault Code: P1483 EGR Valve Module – CAN Communication Error

SET CONDITIONS:
The EGR valve module (L095) detects that the cyclic CAN command message transmitted by the PCI ECU (D420) has been missing for more than 7.5 seconds.

DIAGNOSTIC CONDITION:
This diagnostic runs continuously when the ignition is on.

CORRESPONDING OBD READINESS MONITOR:
None

RESET CONDITION:
This DTC changes to inactive as soon as the fault is no longer detected.

REPAIR VERIFICATION:
1. Clear all DTCs.
2. Test drive or operate the vehicle to meet the diagnostic conditions and set conditions.
3. Did the DTC come back?
– No, repair successful
– Yes, repair unsuccessful

POSSIBLE CAUSES:
CAN wiring

ADDITIONAL INFORMATION:
1. The EGR valve module (L095) is controlled by a cyclic CAN command message transmitted by the PCI ECU (D420) in which the operating mode and the target position are requested.
2. There is still CAN communication between the EGR valve module and PCI ECU with this fault active.
3. The actuator motor is switched off and the EGR valve is fully closed (0% position) with this fault active.
4. Engine torque is reduced after 10 hours of engine operation.

PACCAR MX (2004 Emissions) Fault Code: P1484 EGR Valve Module – Internal Error

SET CONDITIONS:
The EGR valve module (L095) detects that the internal actuator current is too high.

DIAGNOSTIC CONDITION:
This diagnostic runs continuously when the ignition is on.

CORRESPONDING OBD READINESS MONITOR:
None

RESET CONDITION:
This DTC changes to inactive after the ignition is keyed off for at least 15 seconds and keyed on again, and the fault is no longer detected.

REPAIR VERIFICATION:
1. Clear all DTCs.
2. Test drive or operate the vehicle to meet the diagnostic conditions and set conditions.
3. Did the DTC come back?
– No, repair successful
– Yes, repair unsuccessful

POSSIBLE CAUSES:
1. High friction or sticking EGR valve bearings or mechanism
2. Blocked EGR valve

ADDITIONAL INFORMATION:
1. The actuator current is monitored.
2. The actuator motor is switched off and the EGR valve is fully closed (0% position).
3. Engine torque is reduced after 10 hours of engine operation.

PACCAR MX (2004 Emissions) Fault Code: P1485 EGR Valve Module Temperature – Data Valid but Too High

SET CONDITIONS:
The EGR valve module (L095) detects that the temperature of the actuator has been above 142?C for more than 30 seconds.

DIAGNOSTIC CONDITION:
This diagnostic runs continuously when the ignition is on.

CORRESPONDING OBD READINESS MONITOR:
None

RESET CONDITION:
This DTC changes to inactive after the ignition is keyed off for at least 15 seconds and keyed on again, and the fault is no longer detected.

REPAIR VERIFICATION:
1. Clear all DTCs.
2. Test drive or operate the vehicle to meet the diagnostic conditions and set conditions.
3. Did the DTC come back?
– No, repair successful
– Yes, repair unsuccessful

POSSIBLE CAUSES:
1. The ignition is keyed on shortly after a hot engine shutdown.
2. Malfunctioning cooling system. Check the engine cooling system for:
– Low coolant level
– Air in cooling system
– Blocked cooling pipes to the actuator

ADDITIONAL INFORMATION:
1. The temperature is measured on the actuator’s printed circuit board.
2. The actuator motor is switched off and the EGR valve is fully closed (0% position) with this fault active.
3. Engine torque is reduced after 10 hours of engine operation.

PACCAR MX (2004 Emissions) Fault Code: P1486 EGR Valve Module Power Supply – Incorrect

SET CONDITIONS:
The EGR valve module (L095) detects that the actuator power supply is less than 7.5 V or greater than 35 V.

DIAGNOSTIC CONDITION:
This diagnostic runs continuously when the ignition is on.

CORRESPONDING OBD READINESS MONITOR:
None

RESET CONDITION:
This DTC changes to inactive:
1. After the ignition is keyed off for at least 15 seconds and keyed on again and
2. When the actuator power supply is between 8.5 V and 34 V

REPAIR VERIFICATION:
1. Clear all DTCs.
2. Test drive or operate the vehicle to meet the diagnostic conditions and set conditions.
3. Did the DTC come back?
– No, repair successful
– Yes, repair unsuccessful

POSSIBLE CAUSES:
1. Incorrect actuator power supply wiring
2. Malfunction in vehicle power supply system (battery or alternator or wiring)

ADDITIONAL INFORMATION:
1. The actuator power supply is continuously monitored.
2. The actuator motor is switched off and the EGR valve is fully closed (0% position) with this DTC active.
3. Engine torque is reduced after 10 hours of engine operation.

PACCAR MX (2004 Emissions) Fault Code: P1487 EGR Valve Module Position – Malfunction on Sensor

SET CONDITIONS:
The EGR valve module (L095) detects a failure or deviation on the internal shaft position sensor.

DIAGNOSTIC CONDITION:
This diagnostic runs continuously when the ignition is on.

CORRESPONDING OBD READINESS MONITOR:
None

RESET CONDITION:
This DTC changes to inactive after the ignition is keyed off for at least 15 seconds and keyed on again and the error is no longer detected.

REPAIR VERIFICATION:
1. Clear all DTCs.
2. Test drive or operate the vehicle to meet the diagnostic conditions and set conditions.
3. Did the DTC come back?
– No, repair successful
– Yes, repair unsuccessful

POSSIBLE CAUSES:
Bent actuator lever and/or connection rod

ADDITIONAL INFORMATION:
1. The position of the EGR valve is monitored by a shaft position sensor in the actuator.
2. The actuator motor is switched off and the EGR valve is fully closed (0% position) with this DTC active.
3. Engine torque is reduced after 10 hours of engine operation.

PACCAR MX (2004 Emissions) Fault Code: P1488 EGR Valve Module – Out of Calibration

SET CONDITIONS:
The EGR valve module (L095) detects that either:
1. The closed (0%) position is out of range or
2. An internal check routine of the EGR valve module fails to complete successfully.

DIAGNOSTIC CONDITION:
This diagnosis runs after the ignition is keyed ON.

CORRESPONDING OBD READINESS MONITOR:
None

RESET CONDITION:
This DTC changes to INACTIVE if the fault is no longer detected after a key cycle.

REPAIR VERIFICATION:
1. Clear the DTCs.
2. Test drive or operate the vehicle to meet the diagnostic conditions and set conditions.
3. Did the DTC come back?
– No, repair successful.
– Yes, repair unsuccessful.

POSSIBLE CAUSES:
1. E-CAN communication issue
2. Bent actuator lever, valve lever, or connection rod
3. High friction or sticking EGR valve bearings or mechanism
4. Blocked EGR valve

ADDITIONAL INFORMATION:
1. Each time the ignition is keyed ON, the EGR valve compares its closed position (0%) to an ex-factory stored value. If the difference between this ex-factory value and the actual value is higher than the threshold, P1488 is activated.

2. When this DTC is ACTIVE, the actuator motor is switched OFF and the EGR valve is fully closed (0% position).

3. The engine torque is reduced after 10 hours of engine operation.

PACCAR MX (2004 Emissions) Fault Code: P1489 EGR Valve – Stuck Closed

SET CONDITIONS:
The PCI ECU (D420) detects that the EGR valve is stuck closed since the EGR pressure difference is more than 0 bar [0 psi] and the EGR valve is commanded open.

DIAGNOSTIC CONDITION:
This diagnostic runs when the engine is running.

CORRESPONDING OBD READINESS MONITOR:
None

RESET CONDITION:
This DTC changes to inactive when the fault is no longer detected.

REPAIR VERIFICATION:
1. Clear all DTCs.
2. Test drive or operate the vehicle to meet the diagnostic conditions and set conditions.
3. Did the DTC come back?
– No, repair successful
– Yes, repair unsuccessful

POSSIBLE CAUSES:
1. Loose actuator lever and/or connection rod
2. Sticking or blocked EGR valve or mechanism

ADDITIONAL INFORMATION:
1. The position of the actuator shaft, and therefore the position of the EGR valve, is monitored. Valve position: 0% is fully closed and 100% is fully open.
2. The engine NOx emission is, among others, controlled by varying the EGR gas mass flow toward the inlet manifold of the engine.
3. The EGR gas mass flow is calculated using the EGR pressure difference sensor (F751) and the EGR temperature sensor (F749).
4. EGR gas mass flow toward the inlet manifold of the engine is controlled by the EGR valve module (L095).

IMPORTANT: The EGR valve position is not the only parameter that is used to determine the amount of EGR gas flow.

The amount of EGR gas fed back to the inlet manifold mainly depends on the pressure difference between the pressure before turbine and the boost pressure, in combination with the EGR valve position.

PACCAR MX (2004 Emissions) Fault Code: P1490 EGR Gas Flow Detected – While the EGR Valve is Closed

SET CONDITIONS:
The PCI ECU (D420) detects that a certain level of EGR gas mass flow is present, measured by the EGR pressure difference sensor (F751), while the EGR valve is commanded closed.

DIAGNOSTIC CONDITION:
This diagnostic runs when the engine is running.

CORRESPONDING OBD READINESS MONITOR:
None

RESET CONDITION:
This DTC changes to INACTIVE when the ignition is keyed OFF and ON again and the diagnostic runs and passes.

REPAIR VERIFICATION:
1. Clear all DTCs.
2. Test drive or operate the vehicle to meet the diagnostic conditions and set conditions.
3. Did the DTC come back?
– No, repair successful
– Yes, repair unsuccessful

POSSIBLE CAUSES:
1. PCI software bug
2. Freezing of the EGR venturi pressure ports
3. Freezing of the EGR pressure difference sensor pressure ports
4. Contamination of the EGR venturi pressure ports
5. Deviation of the EGR pressure difference sensor (F751)
6. Contamination of the EGR valve due to soot (only applicable if EGR valve position control DTCs are also present)
7. Failure of the EGR valve mechanism (only applicable if EGR valve position control DTCs are also present)

ADDITIONAL INFORMATION:
1. One way in which the engine NOx emission is controlled is by varying the EGR gas mass flow toward the inlet manifold of the engine.
2. The EGR gas mass flow is calculated using the EGR pressure difference sensor (F751) and the EGR temperature sensor (F749).
3. EGR gas mass flow toward the inlet manifold of the engine is controlled by the EGR valve module (L095) but is mainly dependent on the pressure before turbine.