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Tahoe / Yukon Service Manual

DTC P0856

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 P0856 Traction Control Torque Request Circuit Symptom Byte Information: Symptom Byte List Circuit/System Description For an overview of the component/system, refer to: ABS Description and Operation Conditions for Running the DTC Engine Running — Gasoline /Diesel Propulsion Active — Hybrid /EV Conditions for Setting the DTC When certain DTCs are set in the engine control module, it will not be able to perform torque reduction for traction control. A serial data message is sent to the electronic brake control module indicating that torque reduction is currently not allowed. Actions Taken When the DTC Sets Traction/Stability Control Indicator = ON Conditions for Clearing the DTC The conditions for setting the DTC no longer exist. A history DTC will clear after 40 consecutive malfunction-free ignition cycles. Reference Information Schematic Reference Antilock Brake System 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 Circuit/System Verification

  1. Verify there are no other DTCs set, except for DTC P0856. ⇒ If any other DTCs are set Refer to: Diagnostic Trouble Code (DTC) List - Vehicle ⇓ If no other DTCs are set
  2. Replace the component: K20 Engine Control Module
  3. Under normal operating conditions: Verify that no DTCs are set. ⇒ If the DTC sets Replace the appropriate component: K160 Brake System Control Module or K17 Electronic Brake Control Module ⇓ If no DTC is set
  4. 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