Paccar

PACCAR MX (2004 Emissions) Fault Code: P0522 Engine Oil Pressure – Voltage Too Low or Short Circuit to Ground on ECU (D420) Pin (C84)

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.

RESET CONDITION:
The DTC changes to inactive after the diagnostic runs and passes.

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

ADDITIONAL INFORMATION:
Multiple sensor related voltage-too-low DTCs can indicate a malfunction within a 5-V sensor power supply circuit of the PCI ECU.

PACCAR MX (2004 Emissions) Fault Code: P0523 Engine Oil Pressure – Voltage Too High or Short Circuit to Supply on ECU (D420) Pin (C84)

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

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

RESET CONDITION:
The DTC changes to inactive after the diagnostic runs and passes.

POSSIBLE CAUSES:
1. The sensor or actuator signal wiring has a short circuit to supply.
2. A malfunction of the sensor or actuator

PACCAR MX (2004 Emissions) Fault Code: P0524 Engine Oil Pressure – Data Valid but Too Low, Most Severe

SET CONDITIONS:
The PCI ECU (D420) detects that the oil pressure is too low.

DIAGNOSTIC CONDITION:
This diagnostic runs when the engine is running for more than 8 s.

CORRESPONDING OBD READINESS MONITOR:
None

RESET CONDITION:
1. This DTC changes to INACTIVE after the diagnosis runs and passes.
2. This DTC cannot be cleared from the ECU memory.

REPAIR VERIFICATION:
1. Contact your engine field service representative for authorization to clear the warranty DTC.
2. Clear all DTCs.
3. Test drive or operate the vehicle to meet the diagnostic conditions and set conditions.
4. Did the DTC come back? (Can be pending, inactive or active)
– No, repair successful
– Yes, repair unsuccessful

POSSIBLE CAUSES:
1. Oil level too low
2. Very high oil temperature. Check for the presence of relevant DTCs.
3. Faulty oil pressure sensor
4. Faulty oil pump
5. Damaged or missing O-rings on the thorn of the oil filter element

ADDITIONAL INFORMATION:
1. The oil pressure is measured by the oil pressure sensor (F810).
2. A red warning is active on the driver’s display.
3. Engine torque is reduced when this DTC is ACTIVE.
4. This DTC cannot be cleared from the ECU memory.

PACCAR MX (2004 Emissions) Fault Code: P0527 Fan Speed – Data Valid but Too High

SET CONDITIONS:
The PCI ECU (D420) detects that the fan speed is higher than the engine speed.

DIAGNOSTIC CONDITION:
The diagnostic runs when the engine speed is above 1200 rpm.

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 has a short circuit to supply.
2. A malfunction of the sensor or actuator

PACCAR MX (2004 Emissions) Fault Code: P0528 Fan Speed – Data Valid but Too Low

SET CONDITIONS:
The PCI ECU (D420) detects that the fan speed is below 50 rpm.

DIAGNOSTIC CONDITION:
The diagnostic runs when the engine speed is above 1200 rpm.

RESET CONDITION:
This DTC changes to INACTIVE after the diagnosis runs and passes.

POSSIBLE CAUSES:
1. The fan does not rotate freely (for example, fan blade hits the wind tunnel).
2. The sensor or actuator signal wiring is interrupted.
3. The sensor or actuator signal wiring has a short circuit to ground.
4. A malfunction in the power supply of the sensor
5. A malfunction of the electronically controlled fan clutch

PACCAR MX (2004 Emissions) Fault Code: P0541 Grid Heater – Voltage Too Low or Short Circuit to Ground on ECU (D420) Pin (C72) or Pin (C49)

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

ADDITIONAL INFORMATION:
Multiple sensor related voltage-too-low DTCs can indicate a malfunction within a 5-V sensor power supply circuit of the PCI ECU.

PACCAR MX (2004 Emissions) Fault Code: P0542 Grid Heater – Voltage Too High or Short Circuit to Supply on ECU (D420) Pin (C72) or Pin (C49)

SET CONDITIONS:
This DTC is set when the ECU detects a higher 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 has a short circuit to supply.
2. A malfunction of the sensor or actuator

PACCAR MX (2004 Emissions) Fault Code: P0543 Grid Heater – Current Too Low or Open Circuit on ECU (D420) Pin (C72) or Pin (C49)

SET CONDITIONS:
This DTC is set when the PCI ECU (D420) detects a too low current on the control circuit of the grid heater relay (G014).

DIAGNOSTIC CONDITION:
This diagnostic runs continuously after the ignition is switched 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:
Open circuit in the control circuit of the grid heater relay (G014) caused by:
1. Wiring issues between the PCI ECU (D420) and the grid heater relay (G014)
2. Malfunction in the grid heater relay (G014)

PACCAR MX (2004 Emissions) Fault Code: P0562 PCI ECU Power Supply – Data Valid but Too Low on ECU (D420) Pin (B60) or Pin (B61) or Pin (B62)

SET CONDITIONS:
The ECU power supply 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:
Check the power supply level

ADDITIONAL INFORMATION:
Numerous diagnostics will not run anymore.