Paccar

Reason:
Aftertreatment Diesel Exhaust Fluid Tank Heater – Data Valid But Above Normal Operating Range – Moderately Severe Level. The diesel exhaust fluid tank heater is continuously in the ON position.

Effect:
None on performance

Circuit Description:
The aftertreatment diesel exhaust fluid tank heater keeps the diesel exhaust fluid from freezing in the diesel exhaust fluid tank. The tank heater consists of an electrically powered tank heater control valve which controls the flow of engine coolant to a heating coil inside the diesel exhaust fluid tank. The tank heater control valve opens to allow coolant to flow to the heating coil when heating is commanded, and closes when heating is no longer required.

Component Location:
The diesel exhaust fluid tank heater control valve is located near the diesel exhaust fluid tank. Specific location will vary depending on the vehicle OEM. The tank heating coil is internal to the diesel exhaust fluid tank.

Conditions for Running the Diagnostics:
This diagnostic runs continuously when diesel exhaust fluid tank heating is NOT being commanded.

Conditions for Setting the Fault Codes:
The Engine Control Module (ECM) detected the DEF tank temperature was greater than 75°C [170°F] indicating the aftertreatment diesel exhaust fluid tank heater was in the ON position when the ECM was commanding the heater to be in the OFF position.

Action Taken When the Fault Code is Active:
1) The ECM illuminates the amber CHECK ENGINE lamp and/or Malfunction Indicator Lamp (MIL) after the diagnostic fails on two consecutive trips.
2) Diesel exhaust fluid injection into the aftertreatment system is disabled.
3) Engine torque will be reduced if the engine is operated for an extended period of time with this fault active.

Conditions for Clearing the Fault Code:
1) To validate the repair, perform a key cycle, start the engine and let it idle for 1 minute.
2) The fault code status displayed by INSITE™ electronic service tool will change to INACTIVE immediately after the diagnostic runs and passes.
3) The ECM will turn off the amber CHECK ENGINE lamp immediately after the diagnostic runs and passes.
4) For On-Board Diagnostics (OBD) engines, the ECM will extinguish the Malfunction Indicator Lamp (MIL) after three consecutive trips where the diagnostic runs and passes.
5) The Reset All Faults command in INSITE™ electronic service tool can be used to clear active and inactive faults, as well as extinguish the MIL for OBD applications.

Shop Talk:
Before troubleshooting this fault code, make sure the vehicle is not equipped with an auxiliary heating device for the diesel exhaust fluid tank. Such a device can result in overheating the diesel exhaust fluid in the tank.

This fault code may be inactive when the vehicle is brought in for service. Even if inactive, follow the troubleshooting tree completely.

Reason: If there is a problem with the diesel exhaust fluid (DEF) tank heater control valve, the valve is stuck open, there is coolant leaking past the valve seat, or the valve is incorrectly installed, it can take long periods of operation at high load before the tank temperature gradually increases to the fault code threshold value of 77°C [170°F]. As soon as the temperature drops below 75°C [167°F] due to a stopped engine, overnight parking, reduced coolant temperature, and so forth, the fault code will go inactive while the root cause of the issue is still present.

Reference the appropriate OEM wiring diagram when troubleshooting circuits that utilize wiring supplied by the OEM.

For intermittent power supply and datalink communication issues with Aftertreatment Components, it is highly recommended that the OEM Power Distribution Center fuses and relays be thoroughly checked for loose, missing or intermittent connections.

Possible Causes:
1) Aftertreatment diesel exhaust fluid tank heater control valve installed incorrectly, reversed relative to coolant flow direction.
2) Malfunctioning aftertreatment diesel exhaust fluid tank heater control valve – stuck open or leakage past the valve seat.

Reason:
Crankcase Pressure Circuit – Voltage Above Normal or Shorted to High Source. High signal voltage detected at the crankcase pressure circuit.

Effect:
None on performance.

Circuit Description:
The crankcase pressure sensor is used to monitor the pressure inside the crankcase. The engine control module (ECM) supplies the crankcase pressure sensor a 5 volt reference voltage. When the crankcase pressure is low, the sensor signal voltage is low. When the crankcase pressure is high, the sensor signal voltage is near the 5 volt reference voltage. The ECM monitors the crankcase pressure signal circuit voltage to calculate the pressure of the air within the crankcase.

Component Location:
The crankcase pressure sensor is located near the crankcase ventilation filter.

Conditions for Running the Diagnostics:
This diagnostic runs continuously when the keyswitch is in the ON position or when the engine is running.

Conditions for Setting the Fault Codes:
The Engine Control Module (ECM) detected the crankcase pressure signal voltage was out of range high.

Action Taken When the Fault Code is Active:
1) The ECM illuminates the amber CHECK ENGINE lamp and/or the Malfunction Indicator Lamp (MIL) immediately when the diagnostic runs and fails.
2) A default value for the crankcase pressure reading is used.

Conditions for Clearing the Fault Code:
1) To validate the repair, perform a key cycle, start the engine and let it idle for 1 minute.
2) The fault code status displayed by INSITE™ electronic service tool will change to INACTIVE immediately after the diagnostic runs and passes.
3) The ECM will turn off the amber CHECK ENGINE lamp immediately after the diagnostic runs and passes.
4) For On-Board Diagnostics (OBD) engines, the ECM will extinguish the Malfunction Indicator Lamp (MIL) after three consecutive trips where the diagnostic runs and passes.
5) The Reset All Faults command in INSITE™ electronic service tool can be used to clear active and inactive faults, as well as extinguish the MIL for OBD applications.

Shop Talk:
The crankcase pressure sensor shares supply and return wires in the engine harness with other sensors. Opens and shorts in the engine harness can cause multiple fault codes to be active. Before troubleshooting, check for multiple fault codes.

Possible Causes:
1) Open return circuit in the engine harness, connectors, or sensor
2) Signal wire shorted to sensor supply or battery voltage

Reason:
Crankcase Pressure Circuit – Voltage Below Normal or Shorted to Low Source. Low signal voltage detected at the crankcase pressure circuit.

Effect:
None on performance.

Circuit Description:
The crankcase pressure sensor is used to monitor the pressure inside the crankcase. The engine control module (ECM) supplies the crankcase pressure sensor a 5 volt reference voltage. When the crankcase pressure is low, the sensor signal voltage is low. When the crankcase pressure is high, the sensor signal voltage is near the 5 volt reference voltage. The ECM monitors the crankcase pressure signal circuit voltage to calculate the pressure of the air within the crankcase.

Component Location:
The crankcase pressure sensor is located near the crankcase ventilation filter.

Conditions for Running the Diagnostics:
This diagnostic runs continuously when the keyswitch is in the ON position or when the engine is running.

Conditions for Setting the Fault Codes:
The Engine Control Module (ECM) detected the crankcase pressure signal voltage was out of range low.

Action Taken When the Fault Code is Active:
1) The ECM illuminates the amber CHECK ENGINE lamp and/or the Malfunction Indicator Lamp (MIL) immediately when the diagnostic runs and fails.
2) A default value for the crankcase pressure reading is used.

Conditions for Clearing the Fault Code:
1) To validate the repair, perform a key cycle, start the engine and let it idle for 1 minute.
2) The fault code status displayed by INSITE™ electronic service tool will change to INACTIVE immediately after the diagnostic runs and passes.
3) The ECM will turn off the amber CHECK ENGINE lamp immediately after the diagnostic runs and passes.
4) For On-Board Diagnostics (OBD) engines, the ECM will extinguish the Malfunction Indicator Lamp (MIL) after three consecutive trips where the diagnostic runs and passes.
5) The Reset All Faults command in INSITE™ electronic service tool can be used to clear active and inactive faults, as well as extinguish the MIL for OBD applications.

Shop Talk:
The crankcase pressure sensor shares supply and return wires in the engine harness with other sensors. Opens and shorts in the engine harness can cause multiple fault codes to be active. Before troubleshooting, check for multiple fault codes.

Possible Causes:
1) Signal circuit open or shorted to ground in the engine harness or sensor
2) Supply wire open or shorted to ground

Reason:
Water-in-Fuel Indicator – Data Valid But Above Normal Operating Range – Moderately Severe Level. The Water-In-Fuel Indicator indicates that the water level is above warning level.

Effect:
None on performance

Circuit Description:
The water-in-fuel sensor is attached to the fuel filter. The engine control module (ECM) provides a 5 volt reference signal to the water-in-fuel sensor. When the water collected in the fuel filter covers the sensor probes, the water-in-fuel sensor pulls the 5-VDC reference voltage to ground, indicating high water accumulation in the fuel filter.

Component Location:
The water-in-fuel sensor is integrated into the bottom of the OEM supplied suction fuel filter.

Conditions for Running the Diagnostics:
This diagnostic runs continuously when the engine is running.

Conditions for Setting the Fault Codes:
The Engine Control Module (ECM) detected water in fuel for an extended period of time.

Action Taken When the Fault Code is Active:
The ECM illuminates the amber CHECK ENGINE lamp and/or the Malfunction Indicator Lamp (MIL) immediately when the diagnostic runs and fails.

Conditions for Clearing the Fault Code:
1) To validate the repair, perform a key cycle, start the engine and let it idle for 1 minute.
2) The fault code status displayed by INSITE™ electronic service tool will change to INACTIVE immediately after the diagnostic runs and passes.
3) The ECM will turn off the amber CHECK ENGINE lamp immediately after the diagnostic runs and passes.
4) The Reset All Faults command in INSITE™ electronic service tool can be used to clear active and inactive faults, as well as extinguish the MIL for OBD applications.

Shop Talk:
Water in the fuel can do extensive damage to the fuel system, due to the tight tolerances of the fuel system components. The fuel filter must be drained immediately. If this fault code is active and there is no water in the fuel filter, a malfunctioning Water-In-Fuel sensor is a likely cause.

Reference the appropriate OEM wiring diagram when troubleshooting circuits that utilize wiring supplied by the OEM.

Possible Causes:
1) Inactive fault codes
2) Faulty ECM

Reason:
Exhaust Gas Recirculation Valve Delta Pressure – Data Erratic, Intermittent, or Incorrect. An error in the EGR delta pressure signal was detected at initial key ON or the sensor failed the autozero test.

Effect:
Possible reduced engine performance

Circuit Description:
The exhaust gas recirculation (EGR) differential pressure sensor has two ports that sense exhaust pressure. The sensor outputs a voltage which represents the pressure difference between the two ports located across an orifice in the EGR tube. The engine control module (ECM) uses this pressure to determine how much exhaust gas is flowing in the EGR connection tube to the intake manifold. This information is used to control the EGR valve for correct emission levels.The ECM provides a 5 volt supply to the EGR differential pressure sensor on the sensor supply circuit. The ECM also provides a ground on the sensor return circuit. The EGR differential pressure sensor provides a signal to the ECM on the EGR differential pressure sensor signal circuit. This sensor signal voltage changes, based on the differential pressure in the EGR crossover tube.The EGR differential pressure sensor measures the exhaust gas pressure drop across the EGR differential pressure orifice. This pressure drop is used to calculate the amount of EGR flow into the intake manifold.

Component Location:
The EGR differential pressure sensor is mounted on the EGR mass measurement assembly.

Conditions for Running the Diagnostics:
This diagnostic runs at key OFF when the following conditions are met:
1) Engine coolant temperature is 68°C [154°F] or higher.
2) Intake manifold air temperature is 7°C [44°F] or higher.
3) Keyswitch transitions from ON to OFF.

Conditions for Setting the Fault Codes:
The Engine Control Module (ECM) detected the EGR differential pressure sensor was reading higher or lower than a calibratable value when the keyswitch was turned OFF.

Action Taken When the Fault Code is Active:
1) The ECM illuminates the amber CHECK ENGINE lamp and/or the Malfunction Indicator Lamp (MIL) immediately when the diagnostic runs and fails.
2) Diesel exhaust fluid injection into the aftertreatment system is disabled.
3) Active and stationary regeneration of the diesel particulate filter will be disabled.
4) Exhaust Gas Recirculation (EGR) valve operation will be disabled.
5) Engine torque will be reduced if the engine is operated for an extended period of time with this fault active.

Conditions for Clearing the Fault Code:
1) To validate the repair, start the engine and let it idle for 5 minutes. After 5 minutes, shut OFF the engine, perform a key cycle, and leave the key in the ON position for 1 minute.
2) The fault code status displayed by INSITE™ electronic service tool will change to INACTIVE immediately after the diagnostic runs and passes.
3) The ECM will turn off the amber CHECK ENGINE lamp immediately after the diagnostic runs and passes.
4) For On-Board Diagnostics (OBD) engines, the ECM will extinguish the Malfunction Indicator Lamp (MIL) after three consecutive trips where the diagnostic runs and passes.
5) The Reset All Faults command in INSITE™ electronic service tool can be used to clear active and inactive faults, as well as extinguish the MIL for OBD applications.

Shop Talk:
This check is only performed at keyswitch OFF, during the ECM powerdown. During this diagnostic check, the ECM monitors the value of the EGR differential pressure sensor. If this value is outside of a specified range, Fault Code 1866 is set active.

Possible Causes:
1) A damaged EGR differential pressure sensor.
2) High resistance in the wiring harness on the signal or return wire.
3) Plugged or restricted EGR differential pressure sensor flow ports.

Reason:
Sensor Supply 2 Circuit – Voltage Below Normal or Shorted to Low Source. Low voltage detected at the sensor supply number 2 circuit.

Effect:
Possible reduced engine performance.

Circuit Description:
The sensor supply 2 circuit of the engine control module (ECM) provides a 5 volt supply to various sensors on the engine harness. Refer to the wiring diagram for sensor supply identification.

Component Location:
Sensor Supply 2 originates in the Engine Wiring Harness portion of the ECM. It supplies 5 volts to sensors in the engine wiring harness.

Conditions for Running the Diagnostics:
This diagnostic runs continuously when the keyswitch is in the ON position or when the engine is running.

Conditions for Setting the Fault Codes:
The Engine Control Module (ECM) detected the sensor supply 2 signal voltage was out of range low.

Action Taken When the Fault Code is Active:
1) The ECM illuminates the amber CHECK ENGINE lamp and/or the Malfunction Indicator Lamp (MIL) immediately when the diagnostic runs and fails.
2) A default value is used for all of the sensors on the sensor supply 2 circuit.

Conditions for Clearing the Fault Code:
1) To validate the repair, perform a key cycle, start the engine and let it idle for 1 minute.
2) The fault code status displayed by INSITE™ electronic service tool will change to INACTIVE immediately after the diagnostic runs and passes.
3) The ECM will turn off the amber CHECK ENGINE lamp immediately after the diagnostic runs and passes.
4) For On-Board Diagnostics (OBD) engines, the ECM will extinguish the Malfunction Indicator Lamp (MIL) after three consecutive trips where the diagnostic runs and passes.
5) The Reset All Faults command in INSITE™ electronic service tool can be used to clear active and inactive faults, as well as extinguish the MIL for OBD applications.

Shop Talk:
Low voltage on the +5 volt supply line can be caused by a short circuit to ground in a supply line, a short circuit between a supply line and a return line, a malfunctioning sensor, or a malfunctioning ECM power supply.

Possible Causes:
1) Faulty engine harness
2) Loose connector
3) Moisture in or on the connector
4) Wire insulation damage

Reason:
Aftertreatment Diesel Particulate Filter Differential Pressure Sensor Circuit – Voltage Above Normal or Shorted to High Source. High signal voltage detected at the aftertreatment differential pressure sensor circuit.

Effect:
Possible reduced engine performance

Circuit Description:
The engine control module (ECM) provides a 5 volt supply to the aftertreatment diesel particulate filter differential pressure sensor on the sensor supply circuit. The ECM also provides a ground on the sensor return circuit. The aftertreatment diesel particulate filter differential pressure sensor provides a signal to the ECM on the aftertreatment diesel particulate filter differential pressure sensor signal circuit. This sensor signal voltage changes, based on the differential pressure across the aftertreatment diesel particulate filter.

Component Location:
The aftertreatment diesel particulate filter differential pressure sensor is mounted on the diesel particulate filter. It is a combination sensor that detects both diesel particulate filter differential pressure and outlet pressure. Refer to the original equipment manufacturer (OEM) service manual.

Conditions for Running the Diagnostics:
This diagnostic runs continuously when the keyswitch is in the ON position or when the engine is running

Conditions for Setting the Fault Codes:
The Engine Control Module (ECM) detected the aftertreatment diesel particulate filter differential pressure signal voltage was out of range high.

Action Taken When the Fault Code is Active:
1) The ECM illuminates the amber CHECK ENGINE lamp and/or the Malfunction Indicator Lamp (MIL) immediately when the diagnostic runs and fails.
2) A default value for the aftertreatment diesel particulate filter differential pressure is used.
3) Diesel exhaust fluid injection into the aftertreatment system is disabled.
4) Active and stationary regeneration of the diesel particulate filter will be disabled.
5) Exhaust Gas Recirculation (EGR) valve operation will be disabled.
6) Engine torque will be reduced if the engine is operated for an extended period of time with this fault active.

Conditions for Clearing the Fault Code:
1) To validate the repair, perform a key cycle, start the engine and let it idle for 1 minute.
2) The fault code status displayed by INSITE™ electronic service tool will change to INACTIVE immediately after the diagnostic runs and passes.
3) The ECM will turn off the amber CHECK ENGINE lamp immediately after the diagnostic runs and passes.
4) For On-Board Diagnostics (OBD) engines, the ECM will extinguish the Malfunction Indicator Lamp (MIL) after three consecutive trips where the diagnostic runs and passes.
5) The Reset All Faults command in INSITE™ electronic service tool can be used to clear active and inactive faults, as well as extinguish the MIL for OBD applications.

Shop Talk:
Reference the appropriate OEM wiring diagram when troubleshooting circuits that utilize wiring supplied by the OEM.

Possible Causes:
1) Open return circuit in the harness, connectors, or sensor
2) Signal circuit shorted to sensor supply or battery voltage