P111F
DTC P111F
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 provides an overview of each diagnostic category.
DTC Descriptor
DTC P111F
- Fuel Temperature Sensor 1 and 2 Not Plausible
Diagnostic Fault Information
Circuit/System Description
The fuel temperature sensor is a thermistor. The engine control module (ECM) supplies the fuel temperature sensor a bias voltage of 5 volts on the signal circuit and also provides a low reference circuit to the sensor. When the fuel temperature sensor is cold, the resistance is high. The fuel temperature sensor signal voltage remains near the 5 volt bias voltage cold and decreases as the sensor warms. The ECM compares the fuel temperature between fuel temperature sensor 1 and fuel temperature sensor 2 at engine start up. If the difference is above the calibrated threshold, the fault will be detected unless a block heater was responsible for the deviation.
Conditions for Running the DTC
* Engine temperature is greater than -60° C (-76° F).
* Engine speed is between 600-850 RPM.
* Engine off time is greater than 8 hours.
* DTC P111F runs once per trip within the above enabling conditions.
Conditions for Setting the DTC
A fault is detected when fuel temperature sensors 1 and 2 are compared at start up and if the difference exceeds the allowed limit for greater than 0.2 seconds.
Action Taken When the DTC Sets
DTC P111F is a Type B DTC.
Conditions for Clearing the MIL/DTC
DTC P111F is a Type B DTC.
Diagnostic Aids
* Fuel Temperature Sensor 1 is located on the back side of the fuel injection pump.
* Fuel Temperature Sensor 2 also referred to as the Fuel Rail Temperature Sensor is located in the fuel return line near the quick-connect fittings.
Reference Information
Schematic Reference
Engine Controls Schematics [1][2]Electrical Diagrams
Connector End View Reference
Component Connector End Views 1-2 Shift Solenoid (SS) Valve (M30)
Description and Operation
Fuel System Description Fuel System Description
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
* Temperature Versus Resistance (Fuel Temperature Sensor) Temperature Versus Resistance (Fuel Temperature Sensor)Temperature Versus Resistance (ECT Sensors) Temperature Versus Resistance (ECT Sensors)Temperature Versus Resistance (IAT Sensor 1) Temperature Versus Resistance (IAT Sensor 1)Temperature Versus Resistance (IAT Sensor 2) Temperature Versus Resistance (IAT Sensor 2)Temperature Versus Resistance (EGT Sensors) Temperature Versus Resistance (EGT Sensors)Temperature Versus Resistance (EGR Temperature Sensors) Temperature Versus Resistance (EGR Temperature Sensors)Temperature Versus Resistance (Emission Reduction Fluid Injector) [1][2]Diesel Emissions Fluid (DEF) System
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Control Module References Control Module References for scan tool information
Circuit/System Verification
1. Ignition OFF for greater than 8 hours.
2. Ignition ON, block heater not active.
3. Verify DTCs P0182, P0183, P0187, or P0188 are not set.
• If any of the DTCs are set
Refer to Diagnostic Trouble Code (DTC) List - Vehicle Diagnostic Trouble Code (DTC) List - Vehicle.
• If none of the DTCs are set
4. Verify the scan tool Fuel Temperature Sensor 1 and Fuel Temperature Sensor 2 parameters are within 20°C (68°F) of ambient temperature.
• If Fuel Temperature Sensor 1 is not within 20°C (68°F)
Refer to Fuel Temperature Sensor 1 in Circuit/system testing.
• If Fuel Temperature Sensor 2 is not within 20°C (68°F)
Refer to Fuel Temperature Sensor 2 in Circuit/system testing.
• If within 20°C (68°F)
5. All OK.
Circuit/System Testing
Fuel Temperature Sensor 1
1. Ignition OFF.
2. Disconnect the 12-way harness connector at the engine harness jumper. Refer to Inline Harness Connector End Views X100.
Note: Testing for steps 3-4 are performed on the ECM side of the harness connector.
3. Ignition ON, test for 4.8-5.2 V between the signal circuit terminal 3 and ground.
• If less than 4.8 V
Test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K20 engine control module.
• If greater than 5.2 V
Test the signal circuit for a short to voltage. If the circuit tests normal, replace the K20 engine control module.
• If between 4.8-5.2 V
Note: If the fuse opens repair the short to voltage in the low reference circuit.
4. Install a 3 A fused jumper wire between the signal circuit terminal 3 and the low reference circuit terminal 4. Verify the scan tool Fuel Temperature Sensor parameter is greater than 120°C (248°F).
• If less than 120°C (248°F)
Test the low reference circuit for an open, high resistance or short to voltage. If the circuit tests normal, replace the K20 engine control module.
• If greater than 120°C (248°F)
Note: Testing for this step is performed on the engine side of the harness connector.
5. Disconnect the harness connector at the B48 fuel temperature sensor. Test, inspect and repair the items below. If all items test normal, replace the B48 fuel temperature sensor.
* Poor connection at the B48 fuel temperature sensor.
* Open, high resistance or shorted fuel temperature sensor signal circuit.
* Open, high resistance or shorted fuel temperature sensor low reference circuit.
Fuel Temperature Sensor 2
1. Ignition OFF, disconnect the harness connector at the B132 fuel rail temperature sensor.
2. Ignition ON, test for 4.8-5.2 V between the signal circuit terminal 1 and ground.
• If less than 4.8 V
Test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K20 engine control module.
• If greater than 5.2 V
Test the signal circuit for a short to voltage. If the circuit tests normal, replace the K20 engine control module.
Note: If the fuse opens repair the short to voltage in the low reference circuit.
3. Install a 3 A fused jumper wire between the signal circuit terminal 1 and the low reference circuit terminal 2. Verify the scan tool Fuel Temperature Sensor parameter is greater than 120°C (248°F).
• If less than 120°C (248°F)
Test the low reference circuit for an open, high resistance or short to voltage. If the circuit tests normal, replace the K20 engine control module.
• If greater than 120°C (248°F)
4. If all circuits test normal, test or replace the B132 fuel rail temperature sensor.
Component Testing
Measure and record the resistance of the fuel temperature sensor at various temperatures and compare those measurements to the Temperature vs. Resistance table. Refer to Temperature Versus Resistance (Fuel Temperature Sensor) Temperature Versus Resistance (Fuel Temperature Sensor)Temperature Versus Resistance (ECT Sensors) Temperature Versus Resistance (ECT Sensors)Temperature Versus Resistance (IAT Sensor 1) Temperature Versus Resistance (IAT Sensor 1)Temperature Versus Resistance (IAT Sensor 2) Temperature Versus Resistance (IAT Sensor 2)Temperature Versus Resistance (EGT Sensors) Temperature Versus Resistance (EGT Sensors)Temperature Versus Resistance (EGR Temperature Sensors) Temperature Versus Resistance (EGR Temperature Sensors)Temperature Versus Resistance (Emission Reduction Fluid Injector) [1][2]Diesel Emissions Fluid (DEF) System.
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the repair.
* Fuel Temperature Sensor Replacement (Fuel Return Rail) Fuel Temperature Sensor Replacement (Fuel Return Rail)Fuel Temperature Sensor Replacement (Injection Pump) Fuel Temperature Sensor Replacement (Injection Pump)
* Control Module References Control Module References for ECM replacement, programming, and setup.