Paccar

PACCAR MX (2004 Emissions) Fault Code: P0275 Cylinder 5 – Torque Contribution Too Low

SET CONDITIONS:
The PCI ECU (D420) detects that the combustion contribution of cylinder 5 is lower relative to the other cylinders.

DIAGNOSTIC CONDITION:
This diagnostic runs when the engine is running at a steady speed and load, and the vehicle speed is steady.

CORRESPONDING OBD READINESS MONITOR:
Fuel system monitor

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 following conditions:
– Corresponding readiness monitor displays ‘Ready’
– Diagnostic conditions are met
– Set conditions are met
3. Did the DTC come back? (Can be pending, inactive or active)
– No, repair successful
– Yes, repair unsuccessful

POSSIBLE CAUSES:
1. Faulty cylinder 5 injector (under-fueling)
2. Faulty MX Engine Brake cylinder 5
3. Symptom: Slightly reduced power:
– Incorrect valve clearance
– Major imbalance in the drive shaft
4. Symptom: Engine block vibration at high load, damaged flywheel
5. Mechanical defect (for example damaged cam follower or broken valve)

ADDITIONAL INFORMATION:
1. The PCI ECU can detect and identify the cylinder contribution of every cylinder based on analysis of the rotational speed of the crankshaft using a:
– Cylinder-to-cylinder engine speed comparison and
– Cylinder-to-cylinder rotational crankshaft acceleration comparison

2. This DTC can be the result of another DTC that indicates too high of a combustion contribution of another cylinder.

PACCAR MX (2004 Emissions) Fault Code: P0278 Cylinder 6 – Torque Contribution Too Low

SET CONDITIONS:
The PCI ECU (D420) detects that the combustion contribution of cylinder 6 is lower relative to the other cylinders.

DIAGNOSTIC CONDITION:
This diagnostic runs when the engine is running at a steady speed and load, and the vehicle speed is steady.

CORRESPONDING OBD READINESS MONITOR:
Fuel system monitor

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 following conditions:
– Corresponding readiness monitor displays ‘Ready’
– Diagnostic conditions are met
– Set conditions are met
3. Did the DTC come back? (Can be pending, inactive or active)
– No, repair successful
– Yes, repair unsuccessful

POSSIBLE CAUSES:
1. Faulty cylinder 6 injector (under-fueling)
2. Faulty MX Engine Brake cylinder 6
3. Symptom: Slightly reduced power:
– Incorrect valve clearance
– Major imbalance in the drive shaft
4. Symptom: Engine block vibration at high load, damaged flywheel
5. Mechanical defect (for example damaged cam follower or broken valve)

ADDITIONAL INFORMATION:
1. The PCI ECU can detect and identify the cylinder contribution of every cylinder based on analysis of the rotational speed of the crankshaft using a:
– Cylinder-to-cylinder engine speed comparison and
– Cylinder-to-cylinder rotational crankshaft acceleration comparison

2. This DTC can be the result of another DTC that indicates too high of a combustion contribution of another cylinder.

PACCAR MX (2004 Emissions) Fault Code: P0298 Engine Oil Temperature – Data Valid but Too High, Most Severe

SET CONDITIONS:
MX-11:
The PCI ECU (D420) detects that the oil temperature has reached higher than 130°C [266°F] for more than 2 seconds.

MX-13:
The PCI ECU (D420) detects that the oil temperature has reached higher than 128°C [262°F] for more than 2 seconds.

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

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. Malfunction on thermostat in oil module
2. Blocked oil cooler
3. Restriction in the cooling circuit to the oil cooler in the engine block/oil module

ADDITIONAL INFORMATION:
1. The oil temperature is measured by the oil temperature sensor (F808).
2. When this DTC is active:
– The engine torque is reduced.
– A red warning is displayed to the driver.

PACCAR MX (2004 Emissions) Fault Code: P0301 Cylinder 1 – Contribution Too Low or Misfire

SET CONDITIONS:
The PCI ECU (D420) detects that cylinder 1 is misfiring or the combustion contribution is lower relative to the other cylinders.

DIAGNOSTIC CONDITION:
This diagnostic runs when the engine is running at a steady speed and load, and the vehicle speed is steady.

CORRESPONDING OBD READINESS MONITOR:
Misfire monitor

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 following conditions:
– Corresponding readiness monitor displays ‘Ready’
– Diagnostic conditions are met
– Set conditions are met
3. Did the DTC come back?
– No, repair successful
– Yes, repair unsuccessful

POSSIBLE CAUSES:
1. Faulty cylinder 1 injector (not fueling or under-fueling)
2. Loose cylinder 1 injector
3. Faulty MX Engine Brake cylinder 1
4. Symptom: Slightly reduced power:
– Incorrect valve clearance
– Large imbalance in the drive shaft
5. Symptom: Engine block vibration at high load, damaged flywheel
6. Mechanical defect (for example damaged cam follower or broken valve)

ADDITIONAL INFORMATION:
The PCI ECU can detect and identify the cylinder contribution of every cylinder based on analysis of the rotational speed of the crankshaft using a:
1. Cylinder-to-cylinder engine speed comparison and
2. A cylinder-to-cylinder rotational crankshaft acceleration comparison

PACCAR MX (2004 Emissions) Fault Code: P0302 Cylinder 2 – Contribution Too Low or Misfire

SET CONDITIONS:
The PCI ECU (D420) detects that cylinder 2 is misfiring or the combustion contribution is lower relative to the other cylinders.

DIAGNOSTIC CONDITION:
This diagnostic runs when the engine is running at a steady speed and load, and the vehicle speed is steady.

CORRESPONDING OBD READINESS MONITOR:
Misfire monitor

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 following conditions:
– Corresponding readiness monitor displays ‘Ready’
– Diagnostic conditions are met
– Set conditions are met
3. Did the DTC come back?
– No, repair successful
– Yes, repair unsuccessful

POSSIBLE CAUSES:
1. Faulty cylinder 2 injector (not fueling or under-fueling)
2. Loose cylinder 2 injector
3. Faulty MX Engine Brake cylinder 2
4. Symptom: Slightly reduced power:
– Incorrect valve clearance
– Large imbalance in the drive shaft
5. Symptom: Engine block vibration at high load, damaged flywheel
6. Mechanical defect (for example damaged cam follower or broken valve)

ADDITIONAL INFORMATION:
The PCI ECU can detect and identify the cylinder contribution of every cylinder based on analysis of the rotational speed of the crankshaft using a:
1. Cylinder-to-cylinder engine speed comparison and
2. A cylinder-to-cylinder rotational crankshaft acceleration comparison

PACCAR MX (2004 Emissions) Fault Code: P0303 Cylinder 3 – Contribution Too Low or Misfire

SET CONDITIONS:
The PCI ECU (D420) detects that cylinder 3 is misfiring or the combustion contribution is lower relative to the other cylinders.

DIAGNOSTIC CONDITION:
This diagnostic runs when the engine is running at a steady speed and load, and the vehicle speed is steady.

CORRESPONDING OBD READINESS MONITOR:
Misfire monitor

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 following conditions:
– Corresponding readiness monitor displays ‘Ready’
– Diagnostic conditions are met
– Set conditions are met
3. Did the DTC come back?
– No, repair successful
– Yes, repair unsuccessful

POSSIBLE CAUSES:
1. Faulty cylinder 3 injector (not fueling or under-fueling)
2. Loose cylinder 3 injector
3. Faulty MX Engine Brake cylinder 3
4. Symptom: Slightly reduced power:
– Incorrect valve clearance
– Large imbalance in the drive shaft
5. Symptom: Engine block vibration at high load, damaged flywheel
6. Mechanical defect (for example damaged cam follower or broken valve)

ADDITIONAL INFORMATION:
The PCI ECU can detect and identify the cylinder contribution of every cylinder based on analysis of the rotational speed of the crankshaft using a:
1. Cylinder-to-cylinder engine speed comparison and
2. A cylinder-to-cylinder rotational crankshaft acceleration comparison

PACCAR MX (2004 Emissions) Fault Code: P0304 Cylinder 4 – Contribution Too Low or Misfire

SET CONDITIONS:
The PCI ECU (D420) detects that cylinder 4 is misfiring or the combustion contribution is lower relative to the other cylinders.

DIAGNOSTIC CONDITION:
This diagnostic runs when the engine is running at a steady speed and load, and the vehicle speed is steady.

CORRESPONDING OBD READINESS MONITOR:
Misfire monitor

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 following conditions:
– Corresponding readiness monitor displays ‘Ready’
– Diagnostic conditions are met
– Set conditions are met
3. Did the DTC come back?
– No, repair successful
– Yes, repair unsuccessful

POSSIBLE CAUSES:
1. Faulty cylinder 4 injector (not fueling or under-fueling)
2. Loose cylinder 4 injector
3. Faulty MX Engine Brake cylinder 4
4. Symptom: Slightly reduced power:
– Incorrect valve clearance
– Large imbalance in the drive shaft
5. Symptom: Engine block vibration at high load, damaged flywheel
6. Mechanical defect (for example damaged cam follower or broken valve)

ADDITIONAL INFORMATION:
The PCI ECU can detect and identify the cylinder contribution of every cylinder based on analysis of the rotational speed of the crankshaft using a:
1. Cylinder-to-cylinder engine speed comparison and
2. A cylinder-to-cylinder rotational crankshaft acceleration comparison

PACCAR MX (2004 Emissions) Fault Code: P0305 Cylinder 5 – Contribution Too Low or Misfire

SET CONDITIONS:
The PCI ECU (D420) detects that cylinder 5 is misfiring or the combustion contribution is lower relative to the other cylinders.

DIAGNOSTIC CONDITION:
This diagnostic runs when the engine is running at a steady speed and load, and the vehicle speed is steady.

CORRESPONDING OBD READINESS MONITOR:
Misfire monitor

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 following conditions:
– Corresponding readiness monitor displays ‘Ready’
– Diagnostic conditions are met
– Set conditions are met
3. Did the DTC come back?
– No, repair successful
– Yes, repair unsuccessful

POSSIBLE CAUSES:
1. Faulty cylinder 5 injector (not fueling or under-fueling)
2. Loose cylinder 5 injector
3. Faulty MX Engine Brake cylinder 5
4. Symptom: Slightly reduced power:
– Incorrect valve clearance
– Large imbalance in the drive shaft
5. Symptom: Engine block vibration at high load, damaged flywheel
6. Mechanical defect (for example damaged cam follower or broken valve)

ADDITIONAL INFORMATION:
The PCI ECU can detect and identify the cylinder contribution of every cylinder based on analysis of the rotational speed of the crankshaft using a:
1. Cylinder-to-cylinder engine speed comparison and
2. A cylinder-to-cylinder rotational crankshaft acceleration comparison

PACCAR MX (2004 Emissions) Fault Code: P0306 Cylinder 6 – Contribution Too Low or Misfire

SET CONDITIONS:
The PCI ECU (D420) detects that cylinder 6 is misfiring or the combustion contribution is lower relative to the other cylinders.

DIAGNOSTIC CONDITION:
This diagnostic runs when the engine is running at a steady speed and load, and the vehicle speed is steady.

CORRESPONDING OBD READINESS MONITOR:
Misfire monitor

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 following conditions:
– Corresponding readiness monitor displays ‘Ready’
– Diagnostic conditions are met
– Set conditions are met
3. Did the DTC come back?
– No, repair successful
– Yes, repair unsuccessful

POSSIBLE CAUSES:
1. Faulty cylinder 6 injector (not fueling or under-fueling)
2. Loose cylinder 6 injector
3. Faulty MX Engine Brake cylinder 6
4. Symptom: Slightly reduced power:
– Incorrect valve clearance
– Large imbalance in the drive shaft
5. Symptom: Engine block vibration at high load, damaged flywheel
6. Mechanical defect (for example damaged cam follower or broken valve)

ADDITIONAL INFORMATION:
The PCI ECU can detect and identify the cylinder contribution of every cylinder based on analysis of the rotational speed of the crankshaft using a:
1. Cylinder-to-cylinder engine speed comparison and
2. A cylinder-to-cylinder rotational crankshaft acceleration comparison