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Tahoe / Yukon Service Manual

DTC P073D, P073E, P07E4, P07E5, P16F4, P1787, or P1789

DTC P073D, P073E, P07E4, P07E5, P16F4, P1787, or P1789 Diagnostic Instructions Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Review Strategy Based Diagnosis for an overview of the diagnostic approach. Diagnostic Procedure Instructions provides an overview of each diagnostic category. DTC Descriptor DTC P073D Unable to Engage Neutral DTC P073E Unable to Engage Reverse DTC P07E4 Unable to Engage Park DTC P07E5 Unable to Engage Drive DTC P16F4 Control Module Transmission Range Switch Input Circuitry Performance DTC P1787 Unexpected Range Change Detected DTC P1789 Current Transmission Range Unknown Circuit/System Description The internal fault detection is handled inside the device. No external circuit diagnosis is involved. Conditions for Running the DTC The device runs the program to detect an internal fault when power up is commanded. The only requirements are voltage and ground. This program runs even if the voltage is out of the valid operating range. Conditions for Setting the DTC The device has detected an internal malfunction. Action Taken When the DTC Sets The device refuses all additional inputs. Conditions for Clearing the DTC A current DTC clears when the malfunction is no longer present. A history DTC clears when the device ignition cycle counter reaches the reset threshold of 50, without a repeat of the malfunction. Diagnostic Aids This DTC may be stored as a history DTC without affecting the operation of the device. If stored only as a history DTC and not retrieved as a current DTC, do not replace the device. If this DTC is retrieved as both a current and history DTC, replace the device that set the DTC. Reference Information Schematic Reference Electronic Transmission Range Selector Schematics Connector End View Reference Master Electrical Component List Description and Operation Electronic Transmission Range Selector Description Electrical Information Reference Circuit Testing Connector Repairs Testing for Intermittent Conditions and Poor Connections Wiring Repairs Scan Tool Reference Control Module References for scan tool information Circuit/System Verification

  1. Verify all other Transmission related faults are not present. ⇒ If Transmission related faults are present Refer to Diagnostic Trouble Code (DTC) List - Vehicle ⇓ If Transmission related faults are not present
  2. Check for updated software in K71 Transmission Control Module. ⇒ If software is not current Perform the programming and learn procedure for the K71 Transmission Control Module. ⇓ If software is up to date
  3. Check for updated software in K20 Engine Control Module. ⇒ If software is not current Perform the programming for the K20 Engine Control Module. ⇓ If software is up to date
  4. Replace the K71 Transmission Control Module
  5. Verify above mentioned DTC’s are not set. ⇒ If above mentioned DTC’s are set Replace the K20 Engine Control Module ⇓ If above mentioned DTC’s are not set
  6. All OK. Repair Instructions Perform the Diagnostic Repair Verification after completing the repair. Control Module References for device replacement, programming and setup