Paccar

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.

This fault is logged when both the on-idle and off-idle validation switches disagree with the accelerator pedal or lever position signal. Turning the keyswitch ON while partially depressing the accelerator pedal or lever can cause this fault code to go active. This fault will stay active until the pedal or lever is cycled through its full travel.

Possible repairs:

1)Replace the accelerator pedal or lever assembly.
2)Repair or replace the OEM harness.

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.

The oil pressure switch is closed with the engine not running and open when oil pressure is present. This fault code is logged when an open circuit is detected for five consecutive key cycles when the ECM expected a closed circuit at key-on. Possible causes of this fault code include:

1)Damaged engine oil pressure switch
2)Open circuit in the engine oil pressure switch signal wire
3)Damaged ECM
4)Short circuit in the engine oil pressure switch signal wire to a voltage source.

Possible repairs:

1)Repair or replace the engine oil pressure switch.
2)Clean the connector and pins.
3)Repair or replace the engine harness.
4)The removal and installation of the connector may correct the fault.
5)Replace the ECM.

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.

At key ON, before the engine starts, the sensor readings for intake manifold pressure, exhaust gas pressure, engine air pressure, and engine oil pressure are compared to each other. This fault code occurs if the engine oil pressure sensor reading is different from the other sensor readings. This check is only done once after the keyswitch is turned ON.

Possible causes:

1)Stuck in-range engine oil pressure sensor reading
2)High resistance in the engine oil pressure sensor signal or return lines.

Possible repairs:

1)Replace the engine oil pressure sensor.
2)Replace the ECM.
3)Repair or replace the engine harness.

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.

This fault code is logged when the ECM battery supply voltage drops below 6-VDC.

1)Verify that the ECM unswitched power supply is coming from the batteries and not the starter or other device. Check for possible weak batteries.
2)If the ECM unswitched battery supply is taken from the starter, check for low voltage during cranking. Low voltage during cranking can cause the ECM power supply to drop below specifications and log Fault Code 441.

Possible repairs:

1)Tighten the loose connections and clean the terminals.
2)Charge or replace the battery(s).
3)Replace the fuse.
4)Repair or replace the OEM power harness.
5)Repair or replace the damaged wires.

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.

This fault code is logged when the ECM battery supply voltage exceed 36-VDC. Causes of this fault code include:

1)Faulty alternator or regulator that is overcharging the system
2)Batteries connected in series instead of parallel

Possible repairs:

1)Install the battery system correctly.
2)Repair or replace the alternator, regulator, and/or the OEM wiring to the alternator.

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.

Fault Code 449 is activated when the sensed rail fuel pressure exceeds for several consecutive seconds the opening pressure of the fuel pressure relief valve.

Fault Code 449 is not used to indicate a fuel pressure relief valve opening. It is used to indicate a fuel pressure relief valve which fails to open or does not regulate pressure. Troubleshooting must be focused on inspecting the drain line path of the fuel pressure relief valve for restrictions/obstructions and checking or replacing the fuel pressure relief valve. A restriction in the fuel-drain-to-tank return line can prevent unneeded fuel from exiting the fuel system. Check the fuel drain line restriction from the fuel rail to the tank for damage.

The fuel rail pressure sensor must also be checked. When checking the fuel rail pressure sensor accuracy, make sure the high pressure fuel rail is not pressurized. The fuel pump, high-pressure fuel lines, and fuel rail contain very high-pressure fuel. Do not loosen any fittings while the engine is running. Wait at least 10 minutes after shutting down the engine before loosening any fittings in the high-pressure fuel system to allow pressure to decrease to a lower level. There could be a significant amount of time waiting on the rail to depressurize to 0. It could be necessary to manually relieve the pressure from the high pressure fuel rail.

Possible repairs:

1)Replace the drain line or repair the source of the high fuel drain line restriction.
2)Repair the tampering or replace the fuel pressure relief valve.
3)Replace the rail fuel pressure sensor.

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.

Fault Code 449 is activated when the sensed rail fuel pressure exceeds for several consecutive seconds the opening pressure of the fuel pressure relief valve.

Fault Code 449 is not used to indicate a fuel pressure relief valve opening. It is used to indicate a fuel pressure relief valve which fails to open or does not regulate pressure. Troubleshooting must be focused on inspecting the drain line path of the fuel pressure relief valve for restrictions/obstructions and checking or replacing the fuel pressure relief valve. A restriction in the fuel-drain-tank return line can prevent unneeded fuel from exiting the fuel system. Check the fuel drain line restriction from the fuel rail to the tank for damage.

The fuel rail pressure sensor must also be checked. When checking the fuel rail pressure sensor accuracy, make sure the high-pressure fuel rail is not pressurized. The fuel pump, high-pressure fuel lines, and fuel rail contain very high-pressure fuel. Do not loosen any fittings while the engine is operating. Once the engine is keyed off, there could be a significant amount of time waiting on the rail to depressurize to 0. It is necessary to manually relieve the pressure from the high-pressure fuel rail by loosening the pump to rail line at the rail.

Possible repairs:

1)Replace the drain line or repair the source of the high fuel drain line restriction.
2)Repair the tampering or replace the fuel pressure relief valve.
3)Replace the rail fuel pressure sensor.

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 active if there is an open circuit on any of the three pins (+5 volt supply, signal, or return) that connect the sensor or ECM to the wiring harness. This fault will also be active if the signal wire is shorted to a source of voltage. This fault code will become inactive any time the keyswitch is ON and the signal returns to a valid in-range voltage.

Possible causes:

1)Voltage (+5-VDC or higher shorted to the signal wire)
2)Open circuit on the signal wire
3)Open circuit on the +5 volt supply wire
4)Open circuit on the return wire
5)Damaged sensor
6)Damaged ECM.

Possible repairs:

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

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.