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Tahoe / Yukon Service Manual

DTC P268C-P268F, P2690, or P2691

Engine Controls and Fuel - 3.0L LM2 Diesel | Diagnostic Information and Procedures | Document ID: 5401555 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 P268C Cylinder 1 Fuel Injector Calibration Incorrect DTC P268D Cylinder 2 Fuel Injector Calibration Incorrect DTC P268E Cylinder 3 Fuel Injector Calibration Incorrect DTC P268F Cylinder 4 Fuel Injector Calibration Incorrect DTC P2690 Cylinder 5 Fuel Injector Calibration Incorrect DTC P2691 Cylinder 6 Fuel Injector Calibration Incorrect Circuit/System Description This diagnostic applies to microprocessor integrity conditions within the control module. This diagnostic also checks if the control module is not programmed, or is programmed incorrectly. Conditions for Running the DTC Ignition = On Frequency the DTC runs = Continuously — After the running conditions are met Conditions for Setting the DTC Control Module = Internal Malfunction or System Programming Malfunctions Actions Taken When the DTC Sets DTCs listed in the DTC Descriptor category = Type A DTC Conditions for Clearing the DTC DTCs listed in the DTC Descriptor category = Type A DTC Reference Information Connector End View Reference Master Electrical Component List Electrical Information Reference Circuit Testing Connector Repairs Testing for Intermittent Conditions and Poor Connections Wiring Repairs DTC Type Reference Powertrain Diagnostic Trouble Code (DTC) Type Definitions Scan Tool Reference Control Module References Circuit/System Verification

  1. Ignition » On / Vehicle » In Service Mode
  2. Verify DTC P268C, P268D, P268E, P268F, P2690, P2691 is not set. ⇒ If the DTC sets 2.1. Perform the following procedure/test: Fuel Injector Flow Rate Programming 2.2. Verify the DTC does not set. ⇒ If the DTC sets » Replace the component: K20 Engine Control Module ⇓ If the DTC does not set 2.3. All OK. ⇓ If the DTC is not set
  3. All OK. Repair Instructions Perform the Diagnostic Repair Verification after completing the repair: Diagnostic Repair Verification For control module replacement, programming, and setup refer to: Control Module References