Paccar

PACCAR MX (2004 Emissions) Fault Code: P262B PCI ECU Power Supply – Open Circuit on ECU (D420) Pin (B43)

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

CORRESPONDING OBD READINESS MONITOR:
None

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

PACCAR MX (2004 Emissions) Fault Code: P268A Fuel Injection Control – Incorrect

SET CONDITIONS:
The PCI ECU (D420) detects that the fuel injection control is incorrect.

DIAGNOSTIC CONDITION:
This diagnostic runs continuously 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:
Faulty software. Reprogram ECU.

PACCAR MX (2004 Emissions) Fault Code: P3003 PCI ECU Power Supply – Data Valid but Too Low

SET CONDITIONS:
The PCI ECU (D420) detects that the power supply has dropped to below 10 V.

DIAGNOSTIC CONDITION:
This diagnostic runs continuously after starting and running the engine.

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. Alternator malfunctioning
2. PCI ECU power supply, check:
– Whether more ECUs on the vehicle detect incorrect power supply
– Battery voltage
– PCI ECU power supply

ADDITIONAL INFORMATION:
For this diagnostic, the PCI ECU monitors its power supply only during engine operation to detect a running voltage drain-down. It does not detect a cranking voltage drain-down.

PACCAR MX (2004 Emissions) Fault Code: P30B3 CAN – Message (AT1lG1) Time-Out from NOx Sensor before Catalyst

SET CONDITIONS:
This DTC is set when the repetition rate of the received CAN message is lower than expected, or when the message is not received at all.

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

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 issues (interruption or contact resistance)
2. Defective components
3. Incorrect software configuration

PACCAR MX (2004 Emissions) Fault Code: P3100 Coolant Pump Speed – Data Valid but Too High, When Low Speed is Requested

SET CONDITIONS:
The PCI ECU (D420) detects that the coolant pump speed is 250 rpm higher than expected for more than five seconds when the pump is controlled to run at low speed.

DIAGNOSTIC CONDITION:
This diagnostic runs continuously 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. Sticking two-stage coolant pump clutch as a result of debris
2. Malfunctioning coolant pump speed sensor or wiring
3. Malfunctioning two-stage coolant pump

ADDITIONAL INFORMATION:
1. The coolant pump speed is measured by the coolant pump speed sensor (F805).

IMPORTANT: The PCI ECU is not able to detect a short circuit or an open circuit of the coolant pump speed sensor or its wiring. It can only detect if the expected coolant pump speed is reached. If no signal is received from the coolant pump speed sensor, the coolant pump speed (actual) in the diagnostic service tool displays 333 rpm when the engine is running.

2. When the engine is running, the minimum coolant pump speed (actual) that can be displayed in the diagnostic service tool is 333 rpm.

3. The two-stage coolant pump (L142) is controlled by the PCI ECU (D420).

4. Depending on the cooling request by the engine or vehicle (for example cabin heater), the PCI ECU activates the solenoid of the coolant pump to drive the impeller at low or high speed:
– Solenoid activated, the pump runs at high speed
– Solenoid not activated, the pump runs at low speed

5. This DTC may also become active as a result of an active P2605.

6. The driver is not informed by a warning when this DTC is active.

PACCAR MX (2004 Emissions) Fault Code: P3101 Coolant Pump Speed – Data Valid but Too Low, When Low Speed is Requested

SET CONDITIONS:
The PCI ECU (D420) detects that the average coolant pump speed is 400 rpm lower than expected for more than 5 seconds when the pump is controlled to run at low speed.

DIAGNOSTIC CONDITION:
This diagnostic runs continuously when the engine is running and the coolant pump is activated to run at low speed.

CORRESPONDING OBD READINESS MONITOR:
None

RESET CONDITION:
This DTC will change to inactive after the ignition is keyed off and on again and the diagnostic runs and passes. To validate the repair, monitor the coolant pump with the diagnostic service tool when the engine is running.

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. Slipping poly-V-belt
2. Malfunctioning two-stage coolant pump
3. Malfunctioning coolant pump speed sensor or wiring

ADDITIONAL INFORMATION:
1. The coolant pump speed is measured by the coolant pump speed sensor (F805).

IMPORTANT: The PCI ECU is not able to detect a short circuit or an open circuit of the coolant pump speed sensor or its wiring. It can only detect if the expected coolant pump speed is reached. If no signal is received from the coolant pump speed sensor, the coolant pump speed (actual) in the diagnostic service tool displays 333 rpm when the engine is running.

2. When the engine is running, the minimum coolant pump speed (actual) which can be displayed in the diagnostic service tool is 333 rpm.

3. The two-stage coolant pump (L142) is controlled by the PCI ECU (D420).

IMPORTANT: The PCI ECU is not able to detect a short circuit or an open circuit of the coolant pump solenoid or its wiring. It can only detect if the expected coolant pump speed is reached.

4. Depending on the cooling request by the engine or vehicle (for example cabin heater), the PCI ECU activates the solenoid of the coolant pump to drive the impeller at low or high speed:
– Solenoid activated, the pump runs at high speed
– Solenoid not activated, the pump runs at low speed

5. If this DTC becomes active the pump is forced to run at the high speed.

6. The driver is not informed by a warning when this DTC is active.

PACCAR MX (2004 Emissions) Fault Code: P3405 MX Engine Brake Solenoid Valve Cylinder 1-3 – Current Too Low or Open Circuit on ECU (D420) Pin (A17)

SET CONDITIONS:
This DTC is set when the PCI ECU (D420) detects a too low current on the control circuit for engine brake activation.

DIAGNOSTIC CONDITION:
This diagnostic runs during activation of the engine brake.

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. Open circuit in the engine brake control wiring
2. Malfunction of the engine brake solenoid

PACCAR MX (2004 Emissions) Fault Code: P3407 MX Engine Brake Solenoid Valve Cylinder 1-3 – Voltage Too Low or Short Circuit to Ground on ECU (D420) Pin (A17)

SET CONDITIONS:
This DTC is set when the ECU detects a lower voltage than expected on the signal or control circuit of the ECU.

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. The sensor or actuator signal wiring is interrupted.
2. The sensor or actuator signal wiring has a short circuit to ground.
3. A malfunction in the power supply of the sensor or actuator
4. A malfunction of the sensor or actuator

PACCAR MX (2004 Emissions) Fault Code: P3408 MX Engine Brake Solenoid Valve Cylinder 1-3 – Voltage Too High or Short Circuit to Supply on ECU (D420) Pin (A17)

CORRESPONDING OBD READINESS MONITOR:
None

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