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Tahoe / Yukon Service Manual

DTC P27A7-P27AE

Automatic Transmission - 10L80 MHS MQC | Diagnostic Information and Procedures | Document ID: 5224834 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 P27A7 Transmission Control Solenoid Valve 1 Calibration Incorrect DTC P27A8 Transmission Control Solenoid Valve 2 Calibration Incorrect DTC P27A9 Transmission Control Solenoid Valve 3 Calibration Incorrect DTC P27AA Transmission Control Solenoid Valve 4 Calibration Incorrect DTC P27AB Transmission Control Solenoid Valve 5 Calibration Incorrect DTC P27AC Transmission Control Solenoid Valve 6 Calibration Incorrect DTC P27AD Transmission Control Solenoid Valve 7 Calibration Incorrect DTC P27AE Transmission Control Solenoid Valve 8 Calibration Incorrect Circuit/System Description DTC P27A7, P27A8, P27A9, P27AA, P27AB, P27AC, P27AD, P27AE is an informational DTC. The data for each solenoid valve is programmed into the control module K71. For an overview of the component/system, refer to: Electronic Component Description Conditions for Running the DTC K71 Transmission Control Module = Initialization complete Ignition and Start Signal = 9 to 32 V Ignition and Start Switch Signal = On Frequency the DTC runs = Continuously — After the running conditions are met Conditions for Setting the DTC Transmission Control Solenoid Valve 1–8 Calibration Data = Not Programmed Actions Taken When the DTC Sets DTCs listed in the DTC Descriptor category = Type A DTC The control module uses default replacement values. Conditions for Clearing the DTC DTCs listed in the DTC Descriptor category = Type A DTC Reference Information 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 P27A7, P27A8, P27A9, P27AA, P27AB, P27AC, P27AD, P27AE is not set. ⇒ If any of the DTCs are set Refer to: Q77 Transmission Control Solenoid Valve Characterization Programming ⇓ If no DTC is 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 Additional Procedures Transmission Service Fast Learn Procedure — Perform only when the component/system is serviced.