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Tahoe / Yukon Service Manual

DTC P0815, P0816, or P0826 - Manual Mode or Tap Up_Tap Down Switch Malfunction

Automatic Transmission - 10L80 MHS MQC | Diagnostic Information and Procedures | Document ID: 5537608 DTC P0815, P0816, or P0826 - Manual Mode or Tap Up/Tap Down Switch Malfunction 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 P0815 Upshift Switch Circuit DTC P0816 Downshift Switch Circuit DTC P0826 Up and Down Shift Switch Circuit Diagnostic Fault Information

Circuit Short to Ground Open/High Resistance Short to Voltage Signal Performanc
Signal P0826 — — —
Ground — — — —

Mechanical Condition

Component DTC Condition
S2 Automatic Transmission Manual Shift Shaft Position Switch P0815, P0816 Switch Stuck — Closed/On

Typical Scan Tool Data Up and Down Shift Switch

Circuit Short to Ground Open Short to Voltage
Operating Conditions: Ignition = On Parameter Normal Range: Inactive
Signal Invalid Invalid Inactive
Ground Inactive Invalid Invalid

Circuit/System Description

Circuit Description
Signal The control module input circuit has an internal resistance connected to 5 V.
Ground Chassis Ground
Component Description
K9 Body Control Module The control module contains a microprocessor used to process input data to control outputs.
K71 Transmission Control Module The control module receives information from a variety of sensors, switches and serial data information from other control modules. This information is used to control a combination of solenoid valves to obtain the correct line pressure, gear ratio and torque converter clutch operation.
S2 Automatic Transmission Manual Shift Shaft Position Switch The switch S2L has an internal resistor ladder network. A specific resistance is generated dependent on the position of the switch.

The switches are connected in series between the ground and the signal circuit and are inputs to the control module K9. When a switch is pressed, the voltage drop across the switch changes. The driver shift request is sent over serial data to the control module K71. The control module K71 ignores a shift request if the transmission shift lever is not in the manual mode position, or the operating conditions are out of range. Conditions for Running the DTC P0815, P0816 Condition 1 { P0816 } DTC P0815 = Not set { P0815 } DTC P0816 = Not set DTC P0826, P1761, P182E, P1876, P1877, P1915 = Not set DTCs related to the following system/component = Not Set — If equipped – B315A Transmission Range Control Valve 1 Position Switch – B315B Transmission Range Control Valve 2 Position Switch – B316 Transmission Park Valve Position Switch Engine Speed = 400 to 7,500 RPM — For greater than 5 s Ignition and Start Signal = 9 to 32 V Transmission = Not Shifting — For greater than 1 s Transmission Range = Park/Neutral or Reverse Frequency the DTC runs = Continuously — After the running conditions are met P0815, P0816 Condition 2 { P0816 } DTC P0815 = Not set { P0815 } DTC P0816 = Not set DTC P0826, P1761, P182E, P1876, P1877, P1915 = Not set DTCs related to the following system/component = Not Set — If equipped – B315A Transmission Range Control Valve 1 Position Switch – B315B Transmission Range Control Valve 2 Position Switch – B316 Transmission Park Valve Position Switch Engine Speed = 400 to 7,500 RPM — For greater than 5 s Ignition and Start Signal = 9 to 32 V Transmission = Not Shifting — For greater than 1 s Transmission Range = Forward Gear Frequency the DTC runs = Continuously — After the running conditions are met P0826 DTC P1761 = Not set Engine Speed = 400 to 7,500 RPM Ignition and Start Signal = 9 to 32 V Frequency the DTC runs = Continuously — After the running conditions are met — For greater than 5 s Conditions for Setting the DTC P0815 Condition 1 Up and Down Shift Switch = Up or Upshift — For greater than 1 s Condition 2 Up and Down Shift Switch = Up or Upshift — For greater than 2 min P0816 Condition 1 Up and Down Shift Switch = Down or Downshift — For greater than 1 s Condition 2 Up and Down Shift Switch = Down or Downshift — For greater than 2 min P0826 Up and Down Shift Switch = Invalid — For greater than 1 min Actions Taken When the DTC Sets DTCs listed in the DTC Descriptor category = Type C DTC Manual Shift Control = Disabled Tap Up or Tap Down = Disabled Conditions for Clearing the DTC DTCs listed in the DTC Descriptor category = Type C DTC Reference Information Schematic Reference Automatic Transmission Controls 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 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 the scan tool parameter: Up and Down Shift Switch = Inactive ⇒ If not the specified state Refer to: Circuit/System Testing ⇓ If the specified state
  3. Set the parking brake and chock the wheels. Apply and hold the brake pedal.
  4. Engine at Idle While in Drive
  5. S2 Automatic Transmission Manual Shift Shaft Position Switch » L Verify the scan tool parameter: Electronic Transmission Range Selection Request = Active ⇒ If not the specified state Refer to: DTC P073D, P073E, P07E4, P07E5, P16F4, P1787, or P1789 ⇓ If the specified state
  6. Press and hold the switch: S2 Automatic Transmission Manual Shift Shaft Position Switch » − Verify the scan tool parameter: Up and Down Shift Switch = Downshift ⇒ If not the specified state Refer to: Circuit/System Testing ⇓ If the specified state
  7. Press and hold the switch: S2 Automatic Transmission Manual Shift Shaft Position Switch » + Verify the scan tool parameter: Up and Down Shift Switch = Upshift ⇒ If not the specified state Refer to: Circuit/System Testing ⇓ If the specified state
  8. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data. Verify the DTC does not set. ⇒ If the DTC sets Refer to: Circuit/System Testing ⇓ If the DTC is not set
  9. All OK. Circuit/System Testing
  1. Ignition/Vehicle & All vehicle systems » Off
  2. Disconnect the electrical connector: K212 Gear Shift Control Module
  3. Test for less than 10 Ω between the test points: Ground circuit terminal 12 & Ground ⇒ If 10 Ω or greater 3.1. Disconnect the appropriate ground connection: Ground terminal 3.2. Test for less than 2 Ω between the test points: Ground circuit terminal 12 & The other end of the circuit ⇒ If 2 Ω or greater » Repair the open/high resistance in the circuit. ⇒ If less than 2 Ω » Repair the open/high resistance in the ground connection. ⇓ If less than 10 Ω
  4. Ignition » On / Vehicle » In Service Mode
  5. Test for 4.8 to 5.2 V between the test points: Signal circuit terminal 11 & Ground ⇒ If less than 4.8 V 5.1. Disconnect the appropriate electrical connector: K9 Body Control Module 5.2. Test for infinite resistance between the test points: Signal circuit terminal 11 @ Component harness & Ground ⇒ If less than infinite resistance » Repair the short to ground on the circuit. ⇓ If infinite resistance 5.3. Test for less than 5 Ω between the test points: Signal circuit terminal 11 @ Component harness & The other end of the circuit @ Control module harness ⇒ If greater than 5 Ω » Repair the open/high resistance in the circuit. ⇒ If 5 Ω or less » Replace the component: K9 Body Control Module ⇒ If greater than 5.2 V 5.1. Disconnect the appropriate electrical connector: K9 Body Control Module 5.2. Test for less than 1 V between the test points: Signal circuit terminal 11 @ Component harness & Ground ⇒ If 1 V or greater » Repair the short to voltage on the circuit. ⇒ If less than 1 V » Replace the component: K9 Body Control Module ⇓ If between 4.8 and 5.2 V
  6. Test or replace the component: S2 Automatic Transmission Manual Shift Shaft Position Switch Component Testing
  7. Ignition/Vehicle » Off
  8. Disconnect the electrical connector: K212 Gear Shift Control Module
  9. Test for 11,340 to 13,860 Ω between the test points: Signal terminal 11 & Ground terminal 12 ⇒ If not between 11,340 and 13,860 Ω Replace the component: K212 Gear Shift Control Module ⇓ If between 11,340 and 13,860 Ω
  10. Press and hold the switch: S2 Automatic Transmission Manual Shift Shaft Position Switch » +
  11. Test for 1,140 to 1,400 Ω between the test points: Signal terminal 11 & Ground terminal 12 ⇒ If not between 1,140 and 1,400 Ω Replace the component: S2 Automatic Transmission Manual Shift Shaft Position Switch ⇓ If between 1,140 and 1,400 Ω
  12. Press and hold the switch: S2 Automatic Transmission Manual Shift Shaft Position Switch » −
  13. Test for 3,700 to 4,500 Ω between the test points: Signal terminal 11 & Ground terminal 12 ⇒ If not between 3,700 and 4,500 Ω Replace the component: S2 Automatic Transmission Manual Shift Shaft Position Switch ⇓ If between 3,700 and 4,500 Ω
  14. All OK. Repair Instructions Perform the Diagnostic Repair Verification after completing the repair: Diagnostic Repair Verification Electronic Transmission Shift Control Pushbutton Replacement — S2 Automatic Transmission Manual Shift Shaft Position Switch For control module replacement, programming, and setup refer to: Control Module References