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Tahoe / Yukon Service Manual

Fuel Return System Diagnosis

Engine Controls and Fuel - 3.0L LM2 Diesel | Diagnostic Information and Procedures | Document ID: 5577849 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 Circuit/System Description For an overview of the component/system, refer to: Fuel System Description Reference Information Schematic Reference Engine Controls 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 Special Tools GE-41415-60 Engine Induction System Leak Test Adapter/Capless Fuel Fill Adapter Equivalent regional tools: Special Tools Circuit/System Testing

  1. Disconnect the component: Fuel Return Hose @ Engine Refer to: Metal Collar Quick Connect Fitting Service or Plastic Collar Quick Connect Fitting Service
  2. Remove the component: Fuel Tank Filler Cap or Install » Special Tool GE-41415-60 Engine Induction System Leak Test Adapter/Capless Fuel Fill Adapter — Capless Type Fuel Fill
  3. Apply » 6.9 kPa (1 PSI) — Compressed Air @ Fuel Return Hose
  4. Verify air flow can be detected at the component: Fuel Tank Filler Pipe ⇒ If air flow is not detected 4.1. Disconnect the component: Fuel Return Hose @ Fuel Tank 4.2. Apply » 6.9 kPa (1 PSI) — Compressed Air @ Fuel Return Hose 4.3. Verify air flow can be detected at the component: Fuel Return Hose ⇒ If air flow is detected » Replace the component: A7 Fuel Tank Fuel Pump Module ⇒ If air flow is not detected » Repair or replace the component(s) as necessary: Fuel Return Hose ⇓ If air flow is detected
  5. All OK. Repair Instructions Perform the Diagnostic Repair Verification after completing the repair: Diagnostic Repair Verification Fuel Return Pipe Replacement - Front Fuel Return Pipe Replacement - Rear Fuel Return Hose Replacement Fuel Tank Fuel Pump Module Replacement