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Tahoe / Yukon Service Manual

Liftgate Window Release Inoperative (TC2)

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 Diagnostic Fault Information

Circuit number Circuit Function Short to Ground Open/High Resistance Short to Voltage Signal Performan
6190 Signal B176B 23 1 1 —
6188 Control B1769 11 B1769 13 B1769 12 —
4089 Control 2 2 2 —
2050 Ground — B1769 13 — —
2050 Ground — 2 — —
2050 Ground — 1 — —
1. S141 Liftgate Window Release Switch - Exterior = Inoperative 2. M33 Liftgate Window Latch = Inoperative

Circuit/System Description The K194 Rear Gate Module provides the S141 Liftgate Window Release Switch - Exterior with approximately 12V to the signal circuit 6190. When the switch is pressed, the K194 Rear Gate Module will detect the voltage drop in the signal circuit 6190 and will send a serial data message to the K9 Body Control Module to energize the KR162 Liftgate Window Release Relay. Diagnostic Aids A fault in the rear wiper system may cause the power liftgate system and the liftgate window release to become inoperative without setting any DTCs, verify the operation of the rear wiper system prior to performing extensive power liftgate or liftgate window release diagnostics. Refer to Rear Wiper System Malfunction Reference Information Schematic Reference Release Systems Schematics Connector End View Reference Master Electrical Component List Description and Operation Rear Hatch/Gate Description and Operation 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. Ignition » On / Vehicle » In Service Mode
  2. Operate the component: M45 Rear Wiper Motor Verify the component operates and returns to the correct park position ⇒ If the component does not park or operate correctly Refer to: Rear Wiper System Malfunction ⇓ If the component parks and appears to operate correctly
  3. Remove the rear window wiper arm. Refer to: Rear Window Wiper Arm Replacement
  4. Operate the component: M45 Rear Wiper Motor and allow it to cycle and return to the park position without the rear window wiper arm installed.
  5. Operate the component: Key Fob Liftglass Release Button » Pressed Twice Verify the component produces a clicking sound: M33 Liftgate Window Latch ⇒ If a click cannot be heard or felt Refer to: Circuit/System Testing — Test 1 ⇓ If a click can be heard or felt
  6. Verify the scan tool parameter: Rear Gate Lift Glass Release= Inactive ⇒ If not the specified state Refer to: Circuit/System Testing — Test 2 ⇓ If the specified state
  7. Operate the component: S141 Liftgate Window Release Switch - Exterior » Pressed Verify the scan tool parameter: Rear Gate Lift Glass Release= Active ⇒ If not the specified state Refer to: Circuit/System Testing — Test 2 ⇓ If the specified state
  8. A fault is not currently present and may be an intermittent condition Circuit/System Testing Test 1
  9. Ignition/Vehicle » Off
  10. Disconnect the electrical connector: M33 Liftgate Window Latch
  11. Verify a test lamp illuminates between ground circuit terminal 2 and B+. ⇒ If the test lamp does not illuminate 3.1. Repair the open/high resistance on circuit 2050 or the ground connection. ⇓ If the test lamp illuminates
  12. Connect the electrical connector: M33 Liftgate Window Latch
  13. Disconnect the electrical connector: X1 @ X53A Body Wiring Harness Junction Block - Rear
  14. Momentarily connect a 10 A fused jumper wire between control circuit terminal 35 and B+.
  15. Verify the component produces a clicking sound: M33 Liftgate Window Latch ⇒ If a click cannot be heard or felt and the 10 A fuse is OK. 7.1. Test circuit 4089 for an open/high resistance. ⇒ If an open/high resistance is found, repair the fault on the circuit or ground connection. ⇓ If an open/high resistance is not found. 7.2. Test circuit 4089 for an open/high resistance. ⇒ If an open/high resistance is found, repair the fault on the circuit. ⇓ If an open/high resistance is not found. 7.3. Repair or replace the M33 Liftgate Window Latch ⇒ If a click cannot be heard or felt and the 10 A fuse is open. 7.1. Test circuit 4089 for a short to ground. ⇒ If a short to ground is found, repair the fault on the circuit. ⇓ If a short to ground is not found. 7.2. Repair or replace M33 Liftgate Window Latch ⇓ If a click can be heard or felt
  16. Verify a test lamp illuminates between ground circuit terminal 5 X1 and B+. ⇒ If the test lamp does not illuminate 8.1. Repair the open/high resistance on circuit 2050 or the ground connection. ⇓ If the test lamp illuminates
  17. Connect the electrical connector: X1 @ X53A Body Wiring Harness Junction Block - Rear
  18. Disconnect the electrical connector: X7 @ K9 Body Control Module
  19. Ignition » On / Vehicle » In Service Mode
  20. Momentarily connect a 3 A fused jumper wire between the test points: Control circuit terminal  17 X7 & B+
  21. Verify the component produces a clicking sound: M33 Liftgate Window Latch ⇒ If a click cannot be heard or felt and the 3 A fuse is OK. 13.1. Test circuit 6188 for an open/high resistance. ⇒ If an open/high resistance is found, repair the fault on the circuit or ground connection. ⇓ If an open/high resistance is not found. 13.2. Test circuit 6188 for an open/high resistance. ⇒ If an open/high resistance is found, repair the fault on the circuit. ⇓ If an open/high resistance is not found. 13.3. Replace the X53A Body Wiring Harness Junction Block - Rear for an internal fault. ⇒ If a click cannot be heard or felt and the 3 A fuse is open. 13.1. Test circuit 6188 for a short to ground. ⇒ If a short to ground is found, repair the fault on the circuit. ⇓ If a short to ground is not found. 13.2. Replace X53A Body Wiring Harness Junction Block - Rear for an internal fault. ⇓ If a click can be heard or felt
  22. Replace the K9 Body Control Module. Test 2
  23. Ignition/vehicle OFF, disconnect the connector at the S141 Liftgate Window Release Switch - Exterior
  24. Verify a test lamp illuminates between ground circuit terminal 2 and B+. ⇒ If the test lamp does not illuminate 2.1. Repair the open/high resistance on circuit 2050 or the ground connection. ⇓ If the test lamp illuminates
  25. Ignition/vehicle On.
  26. Verify the M33 Liftgate Window Latch is not Active ⇒ If Active 4.1. Test the circuit 6190 for a short to ground ⇒ If a short to ground is found, repair the fault on the circuit. ⇓ If a short to ground is not found. 4.2. Replace the K194 Rear Gate Module. ⇓ If Inactive
  27. Momentarily install a 3 A fused jumper wire between the signal circuit terminal 1 and ground.
  28. Verify the component produces a clicking sound: M33 Liftgate Window Latch ⇒ If the component does not produce a sound and the 3 A fuse is OK 6.1. Test the circuit 6190 for an open/high resistance. ⇒ If an open/high resistance is found, repair the fault on the circuit. ⇓ If an open/high resistance is not found. 6.2. Replace the K194 Rear Gate Module. ⇒ If the component does not produce a sound and the 3 A fuse is open 6.1. Test the circuit 6190 for a short to voltage. ⇒ If a short to voltage is found, repair the fault on the circuit. ⇓ If a short to voltage is not found. 6.2. Replace the K194 Rear Gate Module. ⇓ If the component produces a sound
  29. Replace the S141 Liftgate Window Release Switch - Exterior Component Testing M33 Liftgate Window Latch — Test
  30. Ignition/Vehicle » Off
  31. Disconnect the electrical connector: M33 Liftgate Window Latch
  32. Connect a jumper wire between the test points: Ground terminal 1 & Ground
  33. Momentarily connect a 7.5 A fused jumper wire between the test points: Control terminal 4 & 12 V Verify the component turns On and Off when connecting and disconnecting the jumper wire: M33 Liftgate Window Latch ⇒ If the component does not turn On and Off Replace the component: M33 Liftgate Window Latch ⇓ If the component turns On and Off
  34. All OK. S141 Liftgate Window Release Switch - Exterior — Test
  35. Ignition/Vehicle » Off
  36. Disconnect the electrical connector: S141 Liftgate Window Release Switch - Exterior
  37. Test for infinite resistance between the test points: Signal terminal 1 & Ground terminal 2 » Not Pressed ⇒ If less than infinite resistance Replace the component: S141 Liftgate Window Release Switch - Exterior ⇓ If infinite resistance
  38. Test for less than 3 Ω between the test points: Signal terminal 1 & Ground terminal 2 » Pressed ⇒ If 3 Ω or greater Replace the component: S141 Liftgate Window Release Switch - Exterior ⇓ If less than 3 Ω
  39. All OK. Repair Instructions Perform the Diagnostic Repair Verification after completing the repair: Diagnostic Repair Verification Rear Compartment Lid Release Switch Replacement - Exterior Liftgate Window Latch Replacement Body Wiring Harness Junction Block Replacement For control module replacement, programming, and setup refer to: Control Module References