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Tahoe / Yukon Service Manual

DTC P0545, P0546, P113B, P2080, or P2081

Engine Controls and Fuel - 3.0L LM2 Diesel | Diagnostic Information and Procedures | Document ID: 5471887 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 Descriptors DTC P0545 Exhaust Gas Temperature Sensor Circuit Low DTC P0546 Exhaust Gas Temperature Sensor Circuit High DTC P113B Exhaust Gas Temperature Sensor Not Plausible DTC P2080 Exhaust Gas Temperature Sensor Performance DTC P2081 Exhaust Gas Temperature Sensor Circuit Intermittent Diagnostic Fault Information

Circuit Short to Ground Open/High Resistance Short to Voltage Signal Performanc
Signal P0545 P0546 P0546 P118E
Low Reference — P0546 — P118E
* Additional DTCs may set

Typical Scan Tool Data Exhaust Gas Temperature Sensor 1

Circuit Operating Conditions: Engine = Idling Parameter Normal Range: −39 to 899°C (−38 to 1,650°F) Short to Ground Open Short to Voltage
Signal −40°C (−40°F) 900°C (1,652°F) 900°C (1,652°F)
Low Reference — 900°C (1,652°F) 900°C (1,652°F)

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

Circuit Description
Signal The control module input circuit has an internal resistance connected to 2.4 V.
Low Reference The control module input circuit has an internal resistance connected to 1 V.
Component Description
B131A Exhaust Temperature Sensor 1 The temperature sensor is a negative temperature coefficient thermistor, a resistor which changes based on temperature.
K20 Engine Control Module The control module contains a microprocessor used to process input data to control outputs. The control module controls a series of actuators to ensure optimal engine performance. The control module does this by reading values from a variety of sensors, interprets the data and adjusts the engine actuators accordingly.

Conditions for Running the DTC Ignition/Vehicle = On Ignition Voltage = Greater than 11 V Frequency the DTC runs = Continuously — After the running conditions are met Conditions for Setting the DTC Exhaust Temperature Sensor = Not within a calibrated range 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 Diagnostic Aids After starting a cold engine, the following scan tool parameter value should rise steadily and then stabilize: Exhaust Gas Temperature Sensor 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 for scan tool information Circuit/System Verification

  1. Verify the scan tool parameter: Exhaust Gas Temperature Sensor = −39 to 899°C (−38 to 1,650°F) ⇒ If not between −39 and 899°C (−38 and 1,650°F) Refer to: Circuit/System Testing ⇓ If between −39 and 899°C (−38 and 1,650°F)
  2. 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
  3. All OK. Circuit/System Testing
  4. Ignition/Vehicle & All vehicle systems » Off
  5. Disconnect the electrical connector: B131A Exhaust Gas Temperature Sensor 1
  6. Ignition » On / Vehicle » In Service Mode
  7. Test for 0.5 to 1.5 V between the test points: Low Reference circuit terminal 2 & Ground ⇒ If greater than 1.5 V 4.1. Ignition/Vehicle » Off 4.2. Disconnect the electrical connector: X2 @ K20 Engine Control Module 4.3. Test for less than 1 V between the test points: Low Reference circuit terminal 2 @ Component harness & Ground ⇒ If 1 V or greater » Repair the short to voltage on the circuit. ⇒ If less than 1 V » Replace the component: K20 Engine Control Module ⇓ If less than 0.5 V 4.1. Ignition/Vehicle & All vehicle systems » Off 4.2. Disconnect the electrical connector: X2 @ K20 Engine Control Module 4.3. Test for infinite resistance between the test points: Low Reference circuit terminal 2 & Ground ⇒ If less than infinite resistance » Repair the short to ground on the circuit. ⇓ If infinite resistance 4.4. Test for less than 2 Ω between the test points: Low Reference circuit terminal 2 @ Component harness & The other end of the circuit @ Control module harness ⇒ If 2 Ω or greater » Repair the open/high resistance in the circuit. ⇒ If less than 2 Ω » Replace the component: K20 Engine Control Module ⇒ If between 0.5–1.5 V
  8. Ignition » On / Vehicle » In Service Mode
  9. Verify the scan tool parameter: Exhaust Gas Temperature Sensor 1 = Warmer than 899°C (1,650°F) ⇒ If colder than 899°C (1,650°F) 6.1. Ignition/Vehicle » Off 6.2. Disconnect the electrical connector: K20 Engine Control Module 6.3. Test for infinite resistance between the test points: Signal circuit terminal 1 @ Component harness & Ground ⇒ If less than infinite resistance » Repair the short to ground on the circuit. ⇒ If infinite resistance » Replace the component: K20 Engine Control Module ⇓ If warmer than 899°C (1,650°F)
  10. Connect a 3 A fused jumper wire between the test points: Signal circuit terminal 1 & Ground
  11. Verify the scan tool parameter: Exhaust Gas Temperature Sensor = Colder than −39°C (−38°F) ⇒ If warmer than −39°C (−38°F) 8.1. Ignition/Vehicle » Off & Remove » Jumper wire(s) 8.2. Disconnect the electrical connector: K20 Engine Control Module 8.3. Ignition » On / Vehicle » In Service Mode 8.4. Test for less than 1 V between the test points: Signal circuit terminal 1 @ Component harness & Ground ⇒ If 1 V or greater » Repair the short to voltage on the circuit. ⇓ If less than 1 V 8.5. Ignition/Vehicle » Off 8.6. Test for less than 2 Ω between the test points: Signal circuit terminal 1 @ Component harness & The other end of the circuit @ Control module harness ⇒ If 2 Ω or greater » Repair the open/high resistance in the circuit. ⇒ If less than 2 Ω » Replace the component: K20 Engine Control Module ⇓ If colder than −39°C (−38°F)
  12. Test or replace the component: B131A Exhaust Temperature Sensor 1 Component Testing
  13. Ignition/Vehicle » Off
  14. Disconnect the electrical connector: B131A Exhaust Temperature Sensor 1
  15. Test the resistance between the test points: Signal terminal 1 & Low Reference terminal 2
  16. Verify the value is within the range listed in the table: Temperature Versus Resistance ⇒ If not in the specified range Replace the component: B131A Exhaust Temperature Sensor 1 ⇓ If in the specified range
  17. Test for infinite resistance between the test points: Each terminal of the component & The component’s housing ⇒ If less than infinite resistance Replace the component: B131A Exhaust Temperature Sensor 1 ⇓ If infinite resistance
  18. All OK. Repair Instructions Perform the Diagnostic Repair Verification after completing the repair: Diagnostic Repair Verification Exhaust Gas Temperature Sensor Replacement - Position 1 For control module replacement, programming, and setup refer to: Control Module References