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Tahoe / Yukon Service Manual

DTC B14A3 or B14A4

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 Descriptors DTC B14A3 Left Rear Door Lock Switch Lock Control DTC B14A4 Left Rear Door Lock Switch Unlock Control Symptom Byte Information: Symptom Byte List Diagnostic Fault Information

Circuit number Circuit Function Short to Ground Open/High Resistance Short to Voltage Signal Performan
4001 Signal B14A3 23 2 2 —
4002 Signal B14A4 23 3 3 —
1150 Ground — 1 — —
1. Door Lock Switch Inoperative 2. Door Lock Switch Lock Inoperative 3. Door Lock Switch Unlock Inoperative

Circuit/System Description The K219 Lighting Control Module provides the S13LR Door Lock Switch-Left Rear with signal circuit 4001 and signal circuit 4002. Ground is applied at all times to the S13LR Door Lock Switch- Left Rear. When the lock switch or unlock switch is pressed, ground is applied to the K219 Lighting Control Module through signal circuit 4001 or signal circuit 4002. Conditions for Running the DTC The system voltage is 9–16 V. Conditions for Setting the DTC B14A3 23 Circuit 4001= Short to Ground— For greater than 60 s . B14A4 23 Circuit 4002= Short to Ground— For greater than 60 s . Action Taken When the DTC Sets B14A3 23 4 3  3 The lock request will be ignored and the doors will not lock when using the left rear door lock switch. B14A4 23 The unlock request will be ignored and the doors will not unlock when using the left rear door unlock switch. Conditions for Clearing the DTC The DTC will be current for as long as the fault is present. When the fault is no longer present, the DTC will be a history DTC. A history DTC will clear after 40 ignition cycles. Reference Information Schematic Reference Door Lock/Indicator Schematics Connector End View Reference Master Electrical Component List Description and Operation Power Door Locks 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 for scan tool information Circuit/System Verification

  1. Ignition » On / Vehicle » In Service Mode
  2. Verify the scan tool Left Rear Door Interior Lock Status and the Left Rear Door Interior Unlock Status changes from Inactive to Active while pressing theS13LR Door Lock Switch - Left Rear » Lock Switch & Unlock Switch ⇒ If a parameter does not change Refer to Circuit/System Testing ⇓ If the parameters change from Inactive and Active
  3. A fault is not currently present and may be an intermittent condition Circuit/System Testing
  4. Vehicle OFF and all vehicle systems OFF, disconnect the harness connector at the S13LR Door Lock Switch-Left Rear.
  5. Verify a test lamp illuminates between ground circuit terminal 4 and B+. ⇒ If the test lamp does not illuminate 2.1. Repair the open/high resistance on circuit 1150 or the ground connection. ⇓ If the test lamp illuminates
  6. Ignition » On / Vehicle » In Service Mode
  7. Verify the scan tool Left Rear Door Interior Lock Status parameter is Inactive ⇒ If not Inactive 4.1. Test the circuit 4001 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 K219 Lighting Control Module ⇓ If Inactive
  8. Install a 3 A fused jumper wire between the signal circuit terminal 2 and ground.
  9. Verify the scan tool parameter is now Active. ⇒ If not Active and the 3 A fuse is OK 6.1. Test the circuit 4001 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 K219 Lighting Control Module ⇒ If not Active and the 3 A fuse is open 6.1. Test the circuit 4001 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 K219 Lighting Control Module. ⇓ If Active
  10. Verify the scan tool Left Rear Door Interior Unlock Status parameter is Inactive ⇒ If not Inactive 7.1. Test the circuit 4002 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. Replace the K219 Lighting Control Module. ⇓ If Inactive
  11. Install a 3 A fused jumper wire between the signal circuit terminal 3 and ground.
  12. Verify the scan tool parameter is now Active. ⇒ If not Active and the 3 A fuse is OK 9.1. Test the circuit 4002 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. 9.2. Replace the K219 Lighting Control Module ⇒ If not Active and the 3 A fuse is open 9.1. Test the circuit 4002 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. 9.2. Replace the K219 Lighting Control Module. ⇓ If Active
  13. Replace the S13LR Door Lock Switch-Left Rear. Component Testing
  14. Vehicle OFF, disconnect the harness connector at the S13LR Door Lock Switch — Left Rear.
  15. Test for infinite resistance between the signal terminal 2 and the ground terminal 4 with the switch not pressed. ⇒ If less than infinite resistance Replace the S13LR Door Lock Switch — Left Rear. ⇓ If infinite resistance
  16. Test for infinite resistance between the signal terminal 3 and the ground terminal 4 with the switch not pressed. ⇒ If less than infinite resistance Replace the S13LR Door Lock Switch — Left Rear ⇓ If infinite resistance
  17. Test for less than 2 Ω between the signal terminal 2 and the ground terminal 4 with the switch pressed in the Lock position. ⇒ If 2 Ω or greater Replace the S13LR Door Lock Switch — Left Rear. ⇓ If less than 2 Ω
  18. Test for less than 2 Ω between the signal terminal 3 and the ground terminal 4 with the switch pressed in the Unlock position. ⇒ If 2 Ω or greater Replace the S13LR Door Lock Switch — Left Rear. ⇓ If less than 2 Ω
  19. All OK Repair Instructions Perform the Diagnostic Repair Verification after completing the repair. Door Lock Switch Replacement - Rear Control Module References for exterior lighting control module replacement, programming and setup