Paccar

PACCAR MX (2004 Emissions) Fault Code: P0118 Engine Coolant Temperature – Voltage Too High or Short Circuit to Supply on ECU (D420) Pin (A58)

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: P011A Coolant Pump Speed – Stalled Pump Detected

SET CONDITIONS:
The PCI ECU (D420) detects that the coolant pump speed is below 340 rpm for more than 0.5 seconds.

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. Broken or missing poly-V belt
2. Slipping poly-V-belt Check poly-V-belt tensioner and idlers
3. Malfunctioning coolant pump speed sensor or wiring
4. Malfunctioning two-stage coolant pump
5. 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) which can be displayed in the diagnostic service tool is 333 rpm.

3. For this diagnostic the coolant speed is monitored for detection of a stalled coolant pump by monitoring the poly-V belt presence or slip.

4. In case of a malfunction on the coolant pump speed sensor or wiring, this DTC also becomes active.

5. 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.

6. 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.

7. When this DTC is active:
– The engine torque is reduced.
– The engine runs in protection mode.

PACCAR MX (2004 Emissions) Fault Code: P0121 Accelerator Pedal – Sticking Pedal

SET CONDITIONS:
The PCI ECU (D420) detects that both the accelerator pedal and foot brake pedal are depressed for greater than 10 seconds.

DIAGNOSTIC CONDITION:
This diagnostic runs continuously after ignition is keyed 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 the accelerator pedal
2. Malfunction on the brake pedal
3. Driver operating fault

ADDITIONAL INFORMATION:
For this diagnostic, the foot brake pedal signal (CAN message from brake system) is used to determine if the accelerator pedal (F836) is sticking.

PACCAR MX (2004 Emissions) Fault Code: P0127 Intercooler Temperature – Data Valid but Too High, Most Severe

SET CONDITIONS:
The PCI ECU (D420) detects that the intercooler outlet temperature is more than 100°C [212°F] for more than 30 seconds.

DIAGNOSTIC CONDITION:
This diagnostic runs 300 seconds after the engine is started.

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. Restricted air flow through intercooler/radiator. This can be caused by:
– A fouled bug screen
– A fouled intercooler
– The use of a winter front at temperatures above 4°C [40°F]
– The use of an aftermarket winter front with excessive airflow restriction through
the intercooler/radiator.
2. Faulty engine cooling fan
3. Intercooler temperature sensor deviation

ADDITIONAL INFORMATION:
1. The intercooler outlet temperature is measured before the EGR mixer temperature by the intercooler temperature sensor (F750).
2. Engine torque is reduced when this DTC is active.

PACCAR MX (2004 Emissions) Fault Code: P0135 Lambda Sensor Heater – Current Too Low or Open Circuit on ECU (D420) Pin (C46)

SET CONDITIONS:
The PCI ECU (D420) detects a lower current than expected on the control circuit of the lambda sensor heater.

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. Open circuit in the lambda sensor wiring
2. Lambda sensor failure

PACCAR MX (2004 Emissions) Fault Code: P0148 Fuel Injection Control – Malfunction Detected

SET CONDITIONS:
The PCI ECU (D420) detects that the main fuel injection timing calculation 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: P0149 Fuel Injection Control – Malfunction Detected

IMPORTANT: Do not troubleshoot this DTC.

POSSIBLE CAUSES:
No repairs are necessary.

ADDITIONAL INFORMATION:
The driver is not informed by a warning when this DTC is active.

PACCAR MX (2004 Emissions) Fault Code: P0168 Fuel Temperature – Data Valid but Too High, Most Severe

SET CONDITIONS:
The PCI ECU (D420) detects that the fuel temperature is above 98°C [208°F] for greater than 30 seconds.

DIAGNOSTIC CONDITION:
This diagnosis runs continuously when the ignition is keyed ON.

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. Restriction in the fuel-to-tank return circuit.
2. A low fuel level and a high ambient temperature in combination with a leaking common rail pressure release valve (L094).

ADDITIONAL INFORMATION:
1. The low-pressure fuel temperature is measured by the fuel temperature sensor (F803).
2. Engine torque is reduced when this DTC is ACTIVE.

PACCAR MX (2004 Emissions) Fault Code: P0180 Fuel Temperature – Data Erratic, Intermittent or Incorrect, at Ignition On

SET CONDITIONS:
The PCI ECU (D420) detects that the measured fuel temperature sensor reading differs more than 3°C [5.4°F] from the average of other temperature sensor readings on the engine for more than 5 seconds (after the ignition has been keyed off for at least 8 hours).

DIAGNOSTIC CONDITION:
This diagnostic runs:
1. When the ignition has been keyed off continuously for at least 8 hours
2. Difference between the coolant temperature and ambient temperature is less than 15°C [59°F]
3. Ambient temperature is more than -20°C [-4°F]

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? (Can be pending, inactive or active)
– No, repair successful
– Yes, repair unsuccessful

POSSIBLE CAUSES:
Fuel temperature sensor deviation

ADDITIONAL INFORMATION:
For this diagnostic, the fuel temperature sensor (F803) reading is compared with an average of other temperature sensors on the engine after the ignition has been switched off for at least 8 hours.