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Tahoe / Yukon Service Manual

DTC C1173

Diagnostic Instructions Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Review Strategy Based Diagnosis for an overview of the diagnostic approach. Diagnostic Procedure Instructions provides an overview of each diagnostic category. DTC Descriptor Differential Lock Motor Position Not Plausible Circuit/System Description The K164 Differential Control Module compares the calculated torque based on motor position and the calculated torque based on motor current. Conditions for Running the DTC Ignition ON. System voltage is 9–16V Conditions for Setting the DTC C1173: Current based locking torque does not equal position based locking torque. Action Taken When the DTC Sets System is disabled — clutch open SERVICE REAR AXLE message is displayed in the Driver Information Center Conditions for Clearing the DTC A current DTC clears when the malfunction is no longer present. A history DTC clears when the device ignition cycle counter reaches the reset threshold of 50, without a repeat of the malfunction. Reference Information Schematic Reference Differential Lock Schematics Connector End View Reference Master Electrical Component List Description and Operation Rear Drive Axle Description and Operation Electrical Information Reference Circuit Testing Testing for Intermittent Conditions and Poor Connections Wiring Repairs Scan Tool Reference Control Module References for scan tool information Circuit/System Verification

  1. Check for updated software in K164 Differential Control Module. ⇒ If software is not current 1.1. Perform programming and learn procedure for the K164 Differential Control Module. 1.2. Verify DTC does not reset. ⇒ If the DTC sets Replace the M135 Differential Lock Motor. ⇓ If the DTC does not set 1.3. All OK. ⇓ If software is up to date
  2. Replace the M135 Differential Lock Motor. Repair Instructions Perform the Diagnostic Repair Verification after completing the repair. Limited Slip Differential Clutch Motor Replacement Control Module References for device replacement, programming and setup