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Tahoe / Yukon Service Manual

Active Grille Air Shutter 1 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 P059F Active Grille Air Shutter 1 Performance DTC P151E Active Grille Air Shutter 1 Actuator Signal Message Counter Incorrect Diagnostic Fault Information

Circuit Short to Ground Open/High Resistance Short to Voltage Signal Performanc
Ignition circuit P059F, P151E P059F, P151E — —
LIN Bus U1510, U0284 U1510, U0284 U1510, U0284 U1510, U0284
Ground — P059F, P151E P059F —

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 P059F Desired Active Grille Air Shutter Position ≠ Desired Active Grille Air Shutter Position Achieved — Exceeded Number of Attempts DTC P151E 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: M60A Active Grille Air Shutter 1 Motor Module/M96A Active Grille Air Shutter 1 Actuator.
  3. { If equipped } Disconnect the electrical connector: M60B Active Grille Air Shutter 2 Motor Module/M96B Active Grille Air Shutter 2 Actuator.
  4. Test for less than 10 Ω between the test points: Ground circuit terminal @ Active Grille Air Shutter 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: M60A Active Grille Air Shutter 1 Motor Module/M96A Active Grille Air Shutter 1 Actuator. ⇓ If the test lamp turns On
  7. Ignition/Vehicle OFF, disconnect all LIN devices that share the same LIN serial data circuit.
  8. Ignition ON/Vehicle In Service Mode.
  1. Test for 3.5-12 V between the LIN serial data circuit terminal and ground. ⇒ If less than 3.5 V 9.1. Ignition/Vehicle OFF, disconnect the harness connectors at the K20 Engine Control Module. 9.2. Test for infinite resistance between the LIN serial data circuit terminal and ground. ⇒ If less than infinite resistance, repair the short to ground in the circuit. ⇓ If infinite resistance 9.3. Test for less than 2 Ω in the LIN serial data circuit end to end. ⇒ If 2 Ω or greater, repair the open/high resistance in the circuit. ⇓ If less than 2 Ω 9.4. Replace the K20 Engine Control Module. ⇒ If greater than 12 V 9.1. Ignition/Vehicle OFF, disconnect the harness connectors at the K20 Engine Control Module. 9.2. Ignition ON/Vehicle In Service Mode. 9.3. Test for less than 1 V between the LIN serial data circuit terminal and ground. ⇒ If 1 V or greater, repair the short to voltage in the circuit. ⇓ If less than 1 V 9.4. Replace the K20 Engine Control Module. ⇓ If between 3.5-12 V
  2. Verify how many LIN devices are connected to this LIN circuit. ⇒ If there is only one LIN device 10.1. Ignition/Vehicle OFF, inspect both harness and component connectors for contamination, corrosion, and terminal tension. 10.2. Reconnect the harness connectors at the LIN device. Verify all connectors/terminals are fully seated. 10.3. Ignition ON/Vehicle In Service Mode. 10.4. Verify the DTC is not set again. ⇒ If the DTC is set, replace the LIN device that is not communicating. ⇓ If the DTC is not set 10.5. A fault is currently not present and may be an intermittent condition. ⇓ If there are two or more LIN devices
  3. Ignition/Vehicle OFF, disconnect the harness connectors at the K20 Engine Control Module.
  4. Reconnect the harness connectors at the first LIN device.
  5. Ignition ON/Vehicle In Service Mode.
  6. Test for 3.5-12 V between the LIN serial data circuit terminal at the K20 Engine Control Module and ground. ⇒ If less than 3.5 V or greater than 12 V Replace the LIN device that was just connected. ⇓ If between 3.5-12 V
  7. Ignition/Vehicle OFF, reconnect the harness connectors at another LIN device.
  8. Ignition ON/Vehicle In Service Mode.
  9. Test for 3.5-12 V between the LIN serial data circuit terminal at the K20 Engine Control Module and ground. ⇒ If less than 3.5 V or greater than 12 V Replace the LIN device that was just connected. ⇓ If between 3.5-12 V
  10. Repeat steps 15-17 for the remaining LIN devices until a faulty LIN device is identified. If there is no faulty LIN device, replace the M60A Active Grille Air Shutter 1 Motor Module/M96A  Active Grille Air Shutter 1 Actuator. Repair Instructions Perform the Diagnostic Repair Verification after completing the repair: Diagnostic Repair Verification For control module replacement, programming, and setup refer to: Control Module References