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Tahoe / Yukon Service Manual

DTC P0181-P0184

Engine Controls and Fuel - 3.0L LM2 Diesel | Diagnostic Information and Procedures | Document ID: 5495416 Diagnostic Instructions Perform the Diagnostic System Check prior to using this diagnostic procedure: Diagnostic System Check - Vehicle Review the description of Strategy Based Diagnosis: Strategy Based Diagnosis An overview of each diagnostic category can be found here: Diagnostic Procedure Instructions DTC Descriptor DTC P0181 Fuel Temperature Sensor Performance DTC P0182 Fuel Temperature Sensor Circuit Low DTC P0183 Fuel Temperature Sensor Circuit High DTC P0184 Fuel Temperature Sensor Circuit Erratic Diagnostic Fault Information

Circuit Short to Ground Open/High Resistance Short to Voltage Signal Performanc
Signal P0182 P0183 P0183 P0181, P184
Low Reference — P0183 P0184 P0181, P184

Typical Scan Tool Data Fuel Temperature Sensor

Circuit Short to Ground Open Short to Voltage
Operating Conditions: Engine = Idling — At normal operating temperature. Parameter Normal Range: 2 to 93°C (36 to 200°F)
Signal 95°C (203°F) 0°C (32°F) 0°C (32°F)
Low Reference — 0°C (32°F) —

Circuit/System Description For an overview of the component/system, refer to: Fuel System Description

Circuit Description
Signal The control module input circuit has an internal resistance connected to 5 V.
Low Reference Grounded through the control module.
Component Description
K111 Fuel Pump Power Control Module The control module contains a microprocessor used to process input data to control outputs. The control module communicates with the engine control module via serial data.
R29 Fuel Filter The sensor is a negative temperature coefficient thermistor. As the temperature of the air, fluid, or metal increases, the resistance of the sensor decreases, varying the voltage on the signal circuit. The sensor is integrated within the component: E11A Fuel Heater/Water in Fuel Sensor

Conditions for Running the DTC P0181 DTC P0182, P0183, P1103, P262B = Not set Engine = Running Engine Off Time = Greater than 8 h Engine Run Time = Less than 3 s Ignition and Start Signal = Greater than 8 V ECT Sensor = Warmer than -40°C (-40°F) Frequency the DTC runs = Once — Per drive cycle — After the running conditions are met P0182, P0183 DTC P1103 = Not set Fuel Pump Driver Control Module Voltage Signal = Greater than 8 V Ignition and Start Switch Signal = On or Engine = Running Ignition and Start Signal = Greater than 11 V Frequency the DTC runs = Continuously — After the running conditions are met P0184 DTC P0182, P0183 = Not set Fuel Pump Driver Control Module Voltage Signal = Greater than 8 V Ignition and Start Switch Signal = Greater than 11 V Frequency the DTC runs = Continuously — After the running conditions are met Conditions for Setting the DTC P0181 Fuel Temperature Sensor & ECT Sensor = Not within 20°C (36°F) of each other — For greater than 2 s P0182 Fuel Temperature Sensor = Warmer than 149°C (301°F) — For greater than 2 s P0183 Fuel Temperature Sensor = Colder than -39°C (-38°F) — For greater than 2 s P0184 Fuel Temperature Sensor = The signal is intermittent or changes too fast. — For less than 2 s Actions Taken When the DTC Sets DTCs listed in the DTC Descriptor category = Type B DTC Conditions for Clearing the DTC DTCs listed in the DTC Descriptor category = Type B DTC Reference Information Schematic Reference Engine Controls Schematics Connector End View Reference Master Electrical Component List Electrical Information Reference Circuit Testing Connector Repairs Testing for Intermittent Conditions and Poor Connections Wiring Repairs DTC Type Reference Powertrain Diagnostic Trouble Code (DTC) Type Definitions Scan Tool Reference Control Module References Circuit/System Verification

  1. Ignition » On / Vehicle » In Service Mode
  2. Verify the scan tool parameter: Fuel Temperature Sensor = 2 to 93°C (36 to 200°F) and changes ⇒ If not between 2 and 93°C (36 and 200°F) or does not change Refer to: Circuit/System Testing ⇓ If between 2 and 93°C (36 and 200°F) and changes
  3. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data. Verify the DTC does not set. ⇒ If the DTC sets Refer to: Circuit/System Testing ⇓ If the DTC is not set
  4. All OK. Circuit/System Testing
  1. Ignition/Vehicle & All vehicle systems » Off
  2. Disconnect the electrical connector: R29 Fuel Filter
  3. Test for less than 10 Ω between the test points: Low Reference circuit terminal 7 & Ground ⇒ If 10 Ω or greater 3.1. Disconnect the electrical connector: K111 Fuel Pump Power Control Module 3.2. Test for less than 2 Ω between the test points: Low Reference circuit terminal 7 @ Component harness & Terminal 19 @ Control module harness ⇒ If 2 Ω or greater » Repair the open/high resistance in the circuit. ⇓ If less than 2 Ω 3.3. Test for less than 10 Ω between the test points: Ground circuit terminal 22 @ Control module harness & Ground ⇒ If 10 Ω or greater 3.3.1. Disconnect the ground connection: G405 3.3.2. Test for less than 2 Ω between the test points: Ground circuit terminal 22 & Terminal G405 ⇒ If 2 Ω or greater » Repair the open/high resistance in the circuit. ⇒ If less than 2 Ω » Repair the open/high resistance in the ground connection. ⇒ If less than 10 Ω » Replace the component: K111 Fuel Pump Power Control Module ⇓ If less than 10 Ω
  4. Ignition » On / Vehicle » In Service Mode
  5. Verify the scan tool parameter: Fuel Temperature Sensor = Colder than 2°C (36°F) ⇒ If 2°C (36°F) or warmer 5.1. Ignition/Vehicle » Off 5.2. Disconnect the electrical connector: K111 Fuel Pump Power Control Module 5.3. Test for infinite resistance between the test points: Signal circuit terminal 6 @ Component harness & Ground ⇒ If less than infinite resistance » Repair the short to ground on the circuit. ⇒ If infinite resistance » Replace the component: K111 Fuel Pump Power Control Module ⇓ If colder than 2°C (36°F)
  6. Connect a 3 A fused jumper wire between the test points: Signal circuit terminal 6 & Low Reference circuit terminal 7
  7. Verify the scan tool parameter: Fuel Temperature Sensor = Warmer than 93°C (200°F) ⇒ If 93°C (200°F) or colder 7.1. Ignition/Vehicle » Off & Remove » Jumper wire(s) 7.2. Disconnect the electrical connector: K111 Fuel Pump Power Control Module 7.3. Ignition » On / Vehicle » In Service Mode 7.4. Test for less than 1 V between the test points: Signal circuit terminal 6 @ Component harness & Ground ⇒ If 1 V or greater » Repair the short to voltage on the circuit. ⇓ If less than 1 V 7.5. Ignition/Vehicle » Off 7.6. Test for less than 2 Ω between the test points: Signal circuit terminal 6 @ Component harness & Terminal 4 @ Control module harness ⇒ If 2 Ω or greater » Repair the open/high resistance in the circuit. ⇒ If less than 2 Ω » Replace the component: K111 Fuel Pump Power Control Module ⇓ If warmer than 93°C (200°F)
  8. Replace the component: R29 Fuel Filter Repair Instructions Perform the Diagnostic Repair Verification after completing the repair: Diagnostic Repair Verification Fuel Filter Assembly Replacement — R29 Fuel Filter For control module replacement, programming, and setup refer to: Control Module References