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Tahoe / Yukon Service Manual

DTC P1178

Engine Controls and Fuel - 3.0L LM2 Diesel | Diagnostic Information and Procedures | Document ID: 5501055 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 P1178 Fuel Pump Power Control Module Fuel Level Sensor Internal Supply Voltage Circuit Circuit/System Description

Component Description
K111 Fuel Pump Power Control Module The control module K111 supplies the fuel pump with a 3-phase voltage in order to achieve the desired pump speed required for building fuel line pressure.

Conditions for Running the DTC DTC U0076, U18A2 = Not set Ignition and Start Signal = Greater than 11 V KR200 Engine Controls Sensor Supply Voltage Relay = On Frequency the DTC runs = Continuously — After the running conditions are met Conditions for Setting the DTC K111 Fuel Pump Power Control Module = Internal Malfunction — For greater than 1 s Actions Taken When the DTC Sets DTCs listed in the DTC Descriptor category = Type B DTC Conditions for Clearing the DTC DTCs listed in the DTC Descriptor category = Type B 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 P1178 is not set. ⇒ If the DTC is set Replace the component: K111 Fuel Pump Power Control Module ⇓ 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