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Tahoe / Yukon Service Manual

DTC C11AD or C15AA

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 C11AD Rotary Position Sensor Signal DTC C15AA Rotary Position Sensor Supply 5 Volt Symptom Byte Information: Symptom Byte List. Diagnostic Fault Information

Circuit Short to Ground Open/High Resistance Short to Voltage Signal Performanc
5 V Reference — Terminal 1 @ B139 Transfer Case Two/Four Wheel Drive Actuator Position Sensor C15AA 11 C15AA 13 C15AA 12 C11AD 29, 38
Signal — Terminal 2 @ B139 Transfer Case Two/Four Wheel Drive Actuator Position Sensor C11AD 11 C11AD 13 C11AD 12 C11AD 29, 38
Low Reference — Terminal 3 @ B139 Transfer Case Two/Four Wheel Drive Actuator Position Sensor — C11AD 29 — C11AD 29, 38

Typical Scan Tool Data

Parameter 2WD Automatic 4WD High/Locke 4WD Low d Neutral
Range Actuator Position Sensor -10 to 25° 25 to 175° 25 to 175° -48 to -175° -20 to -48°
Transfer Case Range Position Sensor -10 to 25° 25 to 175° 25 to 175° -48 to -175° -20 to -48°

Circuit/System Description For an overview of the component/system, refer to: Transfer Case Description and Operation

Circuit Description
5 V Reference — Terminal 1 @ B139 Transfer Case Two/Four Wheel Drive Actuator Position Sensor Regulated voltage supplied by the control module.
Signal — Terminal 2 @ B139 Transfer Case Two/Four Wheel Drive Actuator Position Sensor The control module input circuit has an internal resistance connected to ground.
Low Reference — Terminal 3 @ B139 Transfer Case Two/Four Wheel Drive Actuator Position Sensor Grounded through the control module.
Component Description
B139 Transfer Case Two/Four Wheel Drive Actuator Position Sensor The sensor contains a hall effect sensor that varies its output voltage in response to a magnetic field. The hall effect sensor is used for the following sensing application: Transfer Case Range
K69 Transfer Case Control Module The control module contains a microprocessor used to process input data to control outputs.

Conditions for Running the DTC Ignition = On System Voltage = 9 to 17.5 V Frequency the DTC runs = Continuously — After the running conditions are met Conditions for Setting the DTC C11AD 12 Signal circuit = Short to Battery C11AD 11 Signal circuit = Short to Ground C11AD 13 Signal circuit = Open C11AD 29 Condition 1 Signal circuit = Less than 0.25 V Condition 2 Signal circuit = Greater than 6 V Condition 3 Low Reference circuit = Open/High Resistance C11AD 38 Signal circuit = Not between 4.8 and 5.2 V C15AA 12 5 V Reference circuit = Short to Battery C15AA 11 5 V Reference circuit = Short to Ground C15AA 13 5 V Reference circuit = Open Actions Taken When the DTC Sets Shifting = Disabled Driver Information Display = Service 4WD Conditions for Clearing the DTC The conditions for setting the DTC no longer exist. Perform the scan tool configuration/reset function: Range Actuator Correlation Learn 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. Perform the scan tool configuration/reset function: Range Actuator Correlation Learn
  3. Wait 10 s before proceeding to the next step.
  4. Ignition/Vehicle » Off
  5. Wait 30 s before proceeding to the next step.
  6. Ignition » On / Vehicle » In Service Mode
  7. Verify DTC C11AD, C15AA is not set. ⇒ If the DTC is set Refer to: Circuit/System Testing ⇓ If the DTC is not set
  8. Operate the component: S126 Ride Control Switch» 2WD
  9. Verify the scan tool parameter: Transfer Case Range Position Sensor = -10 to 25° ⇒ If not the specified value Refer to: Circuit/System Testing ⇓ If the specified value
  10. Operate the component: S126 Ride Control Switch» 4WD High/Locked
  11. Verify the scan tool parameter: Transfer Case Range Position Sensor = 25 to 175° ⇒ If not the specified value Refer to: Circuit/System Testing ⇓ If the specified value
  12. 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
  13. All OK. Circuit/System Testing
  1. Ignition/Vehicle & All vehicle systems » Off
  2. Disconnect the electrical connector: B139 Transfer Case Two/Four Wheel Drive Actuator Position Sensor
  3. Test for less than 10 Ω between the test points: Low Reference circuit terminal 3 & Ground ⇒ If 10 Ω or greater 3.1. Disconnect the electrical connector: K69 Transfer Case Control Module 3.2. Test for less than 2 Ω between the test points: Low Reference circuit terminal 3 @ Component harness & Terminal 30 @ 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 less than 10 Ω
  4. Ignition » On / Vehicle » In Service Mode
  5. Test for 4.8 to 5.2 V between the test points: 5 V Reference circuit terminal 1 & Low Reference circuit terminal 3 ⇒ If less than 4.8 V 5.1. Ignition/Vehicle » Off 5.2. Disconnect the electrical connector: K69 Transfer Case Control Module 5.3. Test for infinite resistance between the test points: 5 V Reference circuit terminal 1 @ Component harness & Ground ⇒ If less than infinite resistance » Repair the short to ground on the circuit. ⇓ If infinite resistance 5.4. Test for less than 2 Ω between the test points: 5 V Reference circuit terminal 1 @ Component harness & Terminal 20 @ 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 greater than 5.2 V 5.1. Ignition/Vehicle » Off 5.2. Disconnect the electrical connector: 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: 5 V Reference circuit terminal 1 @ Component harness & Ground ⇒ If 1 V or greater » Repair the short to voltage on the circuit. ⇒ If less than 1 V » Replace the component: K69 Transfer Case Control Module ⇓ If between 4.8 and 5.2 V
  6. Test for 2.8 to 3.2 V between the test points: Signal circuit terminal 2 & Ground ⇒ If less than 2.8 V 6.1. Ignition/Vehicle » Off 6.2. Disconnect the electrical connector: K69 Transfer Case Control Module 6.3. Test for infinite resistance between the test points: Signal circuit terminal 2 @ Component harness & Ground ⇒ If less than infinite resistance » Repair the short to ground on the circuit. ⇓ If infinite resistance 6.4. Test for less than 2 Ω between the test points: Signal circuit terminal 2 @ Component harness & Terminal 5 @ 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 greater than 3.2 V 6.1. Ignition/Vehicle » Off 6.2. Disconnect the electrical connector: K69 Transfer Case Control Module 6.3. Ignition » On / Vehicle » In Service Mode 6.4. Test for less than 1 V between the test points: Signal 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: K69 Transfer Case Control Module ⇓ If between 2.8 and 3.2 V
  7. Replace the component: B139 Transfer Case Two/Four Wheel Drive Actuator Position Sensor
  8. Perform the scan tool configuration/reset function: Range Actuator Correlation Learn
  9. Clear DTCs
  10. 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 Replace the component: K69 Transfer Case 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 Transfer Case Two/Four Wheel Drive Actuator Position Sensor Replacement — B139 Transfer Case Two/Four Wheel Drive Actuator Position Sensor For control module replacement, programming, and setup refer to: Control Module References