Paccar

PACCAR MX (2004 Emissions) Fault Code: P1645 PCI ECU 5V Sensor Supply – Voltage Too Low or Short Circuit to Ground

SET CONDITIONS:
The PCI ECU (D420) detects that the internal ‘5V power supply 2’ voltage is too low.

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:
Issues within the ‘5V power supply 2’ with:
1. Sensor wiring
2. Sensor malfunction

ADDITIONAL INFORMATION:
1. Various 5V engine sensors receive their power supply through one of the 5V power supply groups from the PCI ECU (D420).
2. When this DTC is active, all sensors connected to ‘5V power supply 2’ will be out of operation.

PACCAR MX (2004 Emissions) Fault Code: P1650 Red Warning – Short Circuit to Ground or Open Circuit on ECU (D420) Pin (B8)

SET CONDITIONS:
This DTC is set when the ECU detects a lower voltage than expected on pin (B8) of the PCI ECU (D420).

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

CORRESPONDING OBD READINESS MONITOR:
None

RESET CONDITION:
The DTC changes to inactive after 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. Wiring interrupted
2. Wiring short circuit to ground
3. Defective PCI ECU (D420)

PACCAR MX (2004 Emissions) Fault Code: P1652 Red Warning – Short Circuit to Supply on ECU (D420) Pin (B8)

SET CONDITIONS:
This DTC is set when the ECU detects a higher voltage than expected on pin (B8) of the PCI ECU (D420).

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

CORRESPONDING OBD READINESS MONITOR:
None

RESET CONDITION:
The DTC changes to inactive after 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. Wiring short circuit to supply
2. Defective PCI ECU (D420)

PACCAR MX (2004 Emissions) Fault Code: P1653 DtcShared.ViewModels.DtcInfoViewModel

SET CONDITIONS:
This DTC is set when the ECU detects a lower voltage than expected on pin (B4) of the PCI ECU (D420).

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

CORRESPONDING OBD READINESS MONITOR:
None

RESET CONDITION:
The DTC changes to inactive after 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. Wiring interrupted or short circuit to ground
2. Defective PCI ECU (D420)

PACCAR MX (2004 Emissions) Fault Code: P1655 Yellow Warning – Short Circuit to Supply on ECU (D420) Pin (B4)

SET CONDITIONS:
This DTC is set when the ECU detects a higher voltage than expected on pin (B4) of PCI ECU (D420).

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

CORRESPONDING OBD READINESS MONITOR:
None

RESET CONDITION:
The DTC changes to inactive after 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. Wiring, short circuit to supply
2. Defective PCI ECU (D420)

PACCAR MX (2004 Emissions) Fault Code: P1658 PCI ECU – Internal Error

SET CONDITIONS:
The PCI ECU (D420) detects an internal hardware error.

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

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

POSSIBLE CAUSES:
Defective PCI ECU (D420)

PACCAR MX (2004 Emissions) Fault Code: P1674 PCI ECU – Software Error

SET CONDITIONS:
Programmed data in the ECU not correct.

DIAGNOSTIC CONDITION:
This diagnostic runs during start-up of the PCI ECU.

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

POSSIBLE CAUSES:
Software fault

ADDITIONAL INFORMATION:
1. The PCI ECU does not start up.
2. Engine cannot be started.

PACCAR MX (2004 Emissions) Fault Code: P1675 PCI ECU – Software Error

SET CONDITIONS:
Programmed data in the ECU not correct.

DIAGNOSTIC CONDITION:
This diagnostic runs during start-up of the PCI ECU.

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

POSSIBLE CAUSES:
Software fault

ADDITIONAL INFORMATION:
1. The PCI ECU does not start up.
2. Engine cannot be started.

PACCAR MX (2004 Emissions) Fault Code: P1676 PCI ECU – Software Error

SET CONDITIONS:
Programmed data in the ECU not correct.

DIAGNOSTIC CONDITION:
This diagnostic runs during start-up of the PCI ECU.

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

POSSIBLE CAUSES:
Software fault

ADDITIONAL INFORMATION:
1. The PCI ECU does not start up.
2. Engine cannot be started.