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Tahoe / Yukon Service Manual

Active Grille Air Shutter 2 Malfunction

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 P05AE Active Grille Air Shutter 2 Performance DTC P151F Active Grille Air Shutter 2 Actuator Signal Message Counter Incorrect Diagnostic Fault Information

Circuit Short to Ground Open/High Resistance Short to Voltage Signal Performanc
Ignition circuit P05AE, P151F P05AE, P151F — —
LIN Bus U1511, U0285 U1511, U0285 U1511, U0285 U1511, U0285
Ground — P05AE, P151F P05AE —

Circuit/System Description For an overview of the component/system, refer to: Active Grille Air Shutter Description and Operation Conditions for Running the DTC Ignition » On / Vehicle » In Service Mode Conditions for Setting the DTC DTC P05AE Desired Active Grille Air Shutter Position ≠ Desired Active Grille Air Shutter Position Achieved — Exceeded Number of Attempts DTC P151F LIN Bus Communication Malfunction 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 Active Grille Air Shutter 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 there are no related DTCs set in the following system: Active Grille Air Shutter ⇒ If a related DTC is not set Refer to: Diagnostic Trouble Code (DTC) List - Vehicle ⇓ If a related DTC is set
  3. Verify the component location is free of debris, clutter or any obstruction that may reduce airflow which could cause an overheat condition: Active Grille Air Shutter ⇒ If a condition exists Repair or replace as necessary ⇓ If no condition exists
  4. Verify that no DTC listed in the DTC Descriptor Category is set. ⇒ If a related DTC is set Refer to Circuit/System Testing. ⇓ If a related DTC is not set
  5. All OK. Circuit/System Testing
  1. Ignition/Vehicle & All vehicle systems » Off
  2. Disconnect the electrical connector: M96A Active Grille Air Shutter 1 Actuator
  3. Disconnect the electrical connector: M96B Active Grille Air Shutter 2 Actuator
  4. Test for less than 10 Ω between the test points: Ground circuit terminal @ M96B Active Grille Air Shutter 2 Actuator & Ground ⇒ If 10 Ω or greater 4.1. Disconnect the ground connection: Ground circuit terminal 4.2. Test for less than 2 Ω between the test points: Ground circuit terminal @ Component harness & Ground circuit terminal ⇒ 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
  5. Ignition » On / Vehicle » In Service Mode
  6. Verify a test lamp turns On between the test points: Ignition circuit @ Component harness & Ground ⇒ If the test lamp does not turn On and the circuit fuse is OK 6.1. Ignition/Vehicle » Off & Remove » Test lamp 6.2. Test for less than 2 Ω between the test points: Ignition circuit @ Component harness & Output terminal @ M96 Fuse ⇒ If 2 Ω or greater » Repair the open/high resistance in the circuit. ⇒ If less than 2 Ω » Verify the fuse is OK and there is voltage at the fuse. Or ⇒ If less than 2 Ω » Refer to: Power Mode Mismatch ⇒ If the test lamp does not turn On and the circuit fuse is open 6.1. Ignition/Vehicle » Off & Remove » Test lamp 6.2. Test for infinite resistance between the test points: Ignition circuit @ Component harness & Ground ⇒ If less than infinite resistance » Repair the short to ground on the circuit. ⇒ If infinite resistance » Replace the component: M96B Active Grille Air Shutter 2 Actuator ⇓ If the test lamp turns On
  7. Ignition/Vehicle » Off
  8. Test for less than 10 Ω between the test points: LIN Bus — Circuit @ Component harness & Ground ⇒ If less than 10 Ω 8.1. Disconnect the electrical connector: K20 Engine Control Module 8.2. Test for infinite resistance between the test points: LIN Bus — Circuit @ 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 greater than 10 Ω 8.1. Disconnect the electrical connector: K20 Engine Control Module 8.2. Ignition » On / Vehicle » In Service Mode 8.3. Test for less than 1 V between the test points: LIN Bus — Circuit @ Component harness & Ground ⇒ If 1 V or greater » Repair the short to voltage on the circuit. ⇓ If less than 1 V 8.4. Ignition/Vehicle » Off 8.5. Test for less than 2 Ω between the test points: LIN Bus — Circuit @ Component harness & The other end of the circuit ⇒ 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 less than 2 Ω
  9. Test or replace the component: M96B Active Grille Air Shutter 2 Actuator
  10. Operate the vehicle within the Conditions for Running the DTC. Verify the DTC does not set. ⇒ If the DTC sets Replace the component: K20 Engine Control Module ⇓ If the DTC is not set
  11. All OK. Repair Instructions Perform the Diagnostic Repair Verification after completing the repair: Diagnostic Repair Verification Front Bumper Lower Shutter Replacement For control module replacement, programming, and setup refer to: Control Module References