P040F
DTC P040F
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (Diagnostic System Check - Vehicle) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Strategy Based Diagnosis) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Diagnostic Procedure Instructions)provide an overview of each diagnostic category.
DTC Descriptor
DTC P040F
- Exhaust Gas Recirculation (EGR) Temperature Sensor 1-2 Correlation
Diagnostic Fault Information
Typical Scan Tool Data
Circuit/System Description
The exhaust gas recirculation (EGR) temperature sensors are variable resistors that measure the temperature of the exhaust gas at the inlet and outlet of the EGR cooler. The engine control module (ECM) supplies 5 volts to the temperature sensor signal circuit and a ground for the low reference circuit. The ECM uses this rationality diagnostic to determine if the input from EGR temperature sensor 1 or EGR temperature sensor 2 is skewed. The ECM will compare the temperature difference between EGR temperature sensor 1 and the EGR temperature sensor 2 to determine if the temperatures are within an acceptable operating range of each other.
Conditions for Running the DTC
Condition 1
* DTC P0016, P0112, P0113, P0335, P0336, P0340, P0341, P040C, P040D, P041C, or P041D is not set.
* The ignition has been OFF for greater than 8 hours.
* The engine is running.
* The ambient air temperature is greater than -60°C (-76°F).
OR
Condition 2
* DTC P0016, P0112, P0113, P0335, P0336, P0340, P0341, P040C, P040D, P041C, or P041D is not set.
* The ignition has been OFF for greater than 8 hours.
* The engine is running.
* The ambient air temperature is greater than -60°C (-76°F).
* In the first 60 s of engine run time, the ECM determines the block heater is OFF.
AND
* In the first 10 minutes of engine run time, the vehicle speed as been at least 24 km/h (15 mph) for at least 5 minutes and the ECM determines there is no Sunload.
DTC P040F runs once per key cycle when Condition 1 or Condition 2 above is met.
Conditions for Setting the DTC
Condition 1
The ECM detects a temperature difference of greater than 100°C (180°F) between EGR temperature sensors 1 and 2.
OR
Condition 2
The ECM determines the temperature difference between exhaust gas temperature sensor 1 and exhaust gas temperature sensor 2 is greater than 20°C (36°F), but less than or equal to 100°C (180°F), after 10 minutes of engine run time.
Action Taken When the DTC Sets
DTC P040F is a Type B DTC.
Conditions for Clearing the DTC
DTC P040F is a Type B DTC.
Diagnostic Aids
* A slight to moderate resistance in either signal or low reference circuit can widen the spread between the two EGR temperature sensors and cause this DTC to set.
* An EGR temperature sensor that is skewed can widen the spread between the two sensors and cause this DTC to set. Measure and record the resistance of both EGR temperature sensors 1 and 2 at ambient air temperature. Compare those measurements to the Temperature Versus Resistance Temperature Versus Resistance.
* Carefully inspect all EGR temperature sensor terminals for corrosion and poor connections.
* EGR temperature sensors may fail while operating under extreme temperatures. Review the Freeze Frame/Failure Records to verify the failure criteria.
Reference Information
Schematic Reference
Engine Controls Schematics ([1][2]Electrical Diagrams)
Connector End View Reference
Component Connector End Views (Connector End Views By Name)
Electrical Information Reference
* Circuit Testing (Circuit Testing)
* Connector Repairs (Connector Repairs)
* Testing for Intermittent Conditions and Poor Connections (Testing for Intermittent Conditions and Poor Connections)
* Wiring Repairs (Wiring Repairs)
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions (Powertrain Diagnostic Trouble Code (DTC) Type Definitions)
Scan Tool Reference
Control Module References (Programming and Relearning)for scan tool information
Special Tools
J 25070 Heat Gun 500-750°F
Circuit/System Verification
Note: The ignition must be OFF for at least 8 hours prior to starting this procedure.
1. Ignition ON, observe the scan tool EGR Cooler Temp. Sen. 1, EGR Cooler Temp. Sen. 2 and ECT parameters. The EGR Cooler Temp. Sen. 1 and EGR Cooler Temp. Sen. 2 parameters should be within 20°C (36°F) of each other and the ECT parameter.
2. Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
Circuit/System Testing
Note: If you are unable to determine which EGR temperature sensor is skewed, you must perform the Circuit/System Verification first.
1. Ignition OFF, disconnect the harness connector at the appropriate B130A or B130B EGR temperature sensor.
2. Ignition OFF and all vehicle systems OFF. It may take up to 2 minutes for all vehicle systems to power down. Test for less than 5 ohm between the low reference circuit terminal 2 and ground.
• If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the K20 ECM.
3. Ignition ON, verify the scan tool EGR temperature sensor parameter is less than -39°C (-38°F).
• If greater than the specified range, test the signal circuit terminal 1 for a short to ground. If the circuit tests normal, replace the K20 ECM.
4. Install a 3 A fused jumper wire between the signal circuit terminal 1 and the low reference circuit terminal 2. Verify the scan tool EGR temperature sensor parameter is greater than 999°C (1830°F).
• If less than the specified range, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the K20 ECM.
5. If all circuits test normal, test or replace the B130A or B130B EGR temperature sensor.
Component Testing
Note: The J 25070 may be used to evaluate the sensor under high temperature conditions.
Measure and record the resistance of the appropriate EGR temperature sensor and compare those measurements to the Temperature Versus Resistance Temperature Versus Resistance.
If the resistance is not within the specified range for the known temperature, replace the B130A or B130B EGR temperature sensor.
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.
* Exhaust Gas Recirculation Valve Temperature Sensor Replacement - Position 1 (Exhaust Gas Recirculation Valve Temperature Sensor Replacement - Position 1)
* Exhaust Gas Recirculation Valve Temperature Sensor Replacement - Position 2 (Exhaust Gas Recirculation Valve Temperature Sensor Replacement - Position 2)
* Control Module References (Programming and Relearning)for ECM replacement, setup, and programming