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Tahoe / Yukon Service Manual

DTC C1176

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 DTC C1176 Leveling Compressor Motor Control Circuit Diagnostic Fault Information

Circuit Number Circuit Function Short to Ground Open/High Resistance Short to Voltage Signal Performan
2357 Control C1176 11 C1176 13 C1176 12 —
2693 Low Reference — C1176 13 — —

Circuit/System Description The G3 Air Suspension Compressor is supplied voltage and ground by the K5 Automatic Level Control Module. Conditions for Running the DTC Ignition ON Compressor activated Conditions for Setting the DTC C1176 11 The K5 Automatic Level Control Module detects a short to ground on the vehicle level control compressor motor circuit. C1176 12 The K5 Automatic Level Control Module detects a short to voltage on the vehicle level control compressor motor circuit. C1176 13 The K5 Automatic Level Control Module detects an open/high resistance on the vehicle level control compressor motor circuit. Action Taken When the DTC Sets The compressor is offline for the duration of the key cycle. Speed possibly limited. The K5 Automatic Level Control Module sends a message to the instrument panel cluster to display SERVICE LEVELING SYSTEM message. Conditions for Clearing the DTC A present DTC will clear on the next consecutive malfunction-free ignition cycle. A history DTC will clear after 41 consecutive malfunction-free ignition cycles. Reference Information Schematic Reference Electronic Suspension Control Schematics Connector End View Reference Master Electrical Component List Description and Operation Automatic Level Control Description and Operation Electrical Information Reference Circuit Testing Connector Repairs Testing for Intermittent Conditions and Poor Connections Wiring Repairs Scan Tool Reference Control Module References for scan tool information Circuit/System Verification

  1. Ignition ON.
  2. Perform Test Compressor Pneumatic Operation with the scan tool.
  3. Verify Test Compressor Pneumatic Operation passes and compressor operates. ⇒ If test fails or compressor does not operate Refer to Circuit/System Testing ⇓ If test passes and compressor operates
  4. A fault is not currently present and may be an intermittent condition. Circuit/System Testing
  5. Ignition OFF, disconnect the connector at the K5 Automatic Level Control Module, ignition ON/Vehicle in Service Mode.
  6. Test for less than 1 V between the K5 Automatic Level Control Module connector terminal 30 and ground. ⇒ If 1 V or greater Repair the short to voltage on the circuit. ⇓ If less than 1 V
  7. Ignition OFF.
  8. Disconnect harness connector at the G3 Air Suspension Compressor.
  9. Test for infinite resistance between K5 Automatic Level Control Module connector terminals listed below and ground. Terminal 30 Terminal 46 ⇒ If less than infinite resistance Repair the short to ground on the circuit. ⇓ If Infinite resistance
  10. Test for less than 2 Ω between G3 Air Suspension Compressor connector terminal 1 and K5 Automatic Level Control Module connector terminal 30. ⇒ If 2 Ω or greater Repair the open/high resistance in the circuit. ⇓ If less than 2 Ω
  11. Test for less than 2 Ω between G3 Air Suspension Compressor connector terminal 2 and K5 Automatic Level Control Module connector terminal 46. ⇒ If 2 Ω or greater Repair the open/high resistance in the circuit. ⇓ If less than 2 Ω
  12. Test for less than 2 Ω between the G3 Air Suspension Compressor connector terminal 2 and G3 Air Suspension Compressor connector terminal 1. ⇒ If 2 Ω or greater Replace the G3 Air Suspension Compressor ⇓ If less than 2 Ω
  13. Replace the K5 Automatic Level Control Module. Repair Instructions Perform the Diagnostic Repair Verification after completing the repair. Control Module References for K5 Automatic Level Control Module replacement, programming, and setup.