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Tahoe / Yukon Service Manual

DTC C11A4 (1)

DTC C11A4 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 C11A4 Unable to Complete Shift Symptom Byte Information: Symptom Byte List. Circuit/System Description For an overview of the component/system, refer to: Transfer Case Description and Operation Conditions for Running the DTC Ignition = On System Voltage = 9 to 17.5 V Conditions for Setting the DTC During shifting if software detect single block event for 3 times on 3 different shift requests, or During shifting if software detect double block event for 3 times. Actions Taken When the DTC Sets Shifting = Disabled Driver Information Display = 4WD Off or Service 4WD Conditions for Clearing the DTC The conditions for setting the DTC no longer exist. A history DTC will clear after 40 consecutive malfunction-free ignition cycles. Reference Information Schematic Reference Transfer Case Control 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 Scan Tool Reference Control Module References Circuit/System Verification

  1. Ignition » On / Vehicle » In Service Mode
  2. Clear DTCs
  3. Perform the scan tool control function: Transfer Case Range » Neutral Transfer Case Range » 2WD Transfer Case Range » 4WD/AWD Automatic Transfer Case Range » 4WD High/Locked Transfer Case Range » 4WD Low Verify the scan tool parameter: Range Actuator Position = Neutral Range Actuator Position = 2WD Range Actuator Position = 4WD/AWD Automatic Range Actuator Position = 4WD High/Locked Range Actuator Position = 4WD Low ⇒ If not the specified values Refer to: Circuit/System Testing ⇓ If the specified values
  4. Verify DTC C11A4 is not set. ⇒ If the DTC is set Refer to: Circuit/System Testing ⇓ If the DTC is not set
  5. 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
  6. All OK. Circuit/System Testing
  7. Ignition/Vehicle » Off
  8. Disconnect the electrical connector: A16 Transfer Case Four Wheel Drive Actuator
  9. Connect a test lamp between the test points: Control circuit terminal A & Control circuit terminal D
  10. Ignition » On / Vehicle » In Service Mode
  11. Perform the scan tool control function: Range Actuator Verify the test lamp state: Range Actuator » Idle = Test lamp Off Range Actuator » Clockwise = Test lamp On Range Actuator » Counterclockwise = Test lamp On ⇒ If not the specified state 5.1. Ignition/Vehicle » Off & Remove » Test lamp 5.2. Disconnect the electrical connector: X1 @ K69 Transfer Case Control Module 5.3. Ignition » On / Vehicle » In Service Mode 5.4. Test for less than 1 V between the test points: Control circuit terminal A @ Component harness & Ground Control circuit terminal D @ Component harness & Ground ⇒ If 1 V or greater » Repair the short to voltage on the circuit. ⇓ If less than 1 V 5.5. Ignition/Vehicle » Off 5.6. Test for infinite resistance between the test points: Control circuit terminal A @ Component harness & Ground Control circuit terminal D @ Component harness & Ground ⇒ If less than infinite resistance » Repair the short to ground on the circuit. ⇓ If infinite resistance 5.7. Test for less than 2 Ω between the test points: Control circuit terminal A @ Component harness & Terminal 38 @ Control module harness Control circuit terminal D @ Component harness & Terminal 13 @ Control module harness ⇒ If 2 Ω or greater » Repair the open/high resistance in the circuit. ⇒ If less than 2 Ω » Replace the component: K69 Transfer Case Control Module ⇓ If the specified state
  12. Verify a condition does not exist with the component: Transfer Case Assembly ⇒ If a condition exists » Repair or replace as necessary ⇓ If no condition exists
  13. Test or replace the component: A16 Transfer Case Four Wheel Drive Actuator Repair Instructions Perform the Diagnostic Repair Verification after completing the repair: Diagnostic Repair Verification Transfer Case Two/Four Wheel Drive Actuator Replacement — A16 Transfer Case Four Wheel Drive Actuator For control module replacement, programming, and setup refer to: Control Module References