Skip to content
Tahoe / Yukon Service Manual

Memory Seat Feature Malfunction

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. Diagnostic Fault Information

Circuit Number Circuit Function Short to Ground Open/High Resistance Short to Voltage Signal Performan
615 Signal B1105 1 B1105 B1105 B19B6
614 Signal — 1 — —
1151 Ground — 1 — —
1. Memory recall is inoperative

Circuit/System Description Ground is supplied to the front seat adjuster memory switch - driver at all times. When the front seat adjuster memory switch - driver is pressed, the 12 V signal circuit from the seat adjuster memory module is pulled low through the switch contacts indicating the memory store request. When a memory position switch is pressed, the 5 V signal circuit from the seat adjuster memory module is pulled low through the switch contacts and series of resistors indicating the memory recall or store request. In response to this signal, the seat adjuster memory module commands the appropriate seat motors to move to the pre-recorded seat positions stored in memory or to store the current positions to a memory position. Additionally, the seat adjuster memory module sends serial data messages indicating the request to recall or store a memory position. Modules that locally recall and store positions are the mirror, column, seat bolster, and heads up display modules (When equipped). Diagnostic Aids After servicing the memory seat system it is recommended to move the seat to a central, middle range position, then perform the memory store operation for memory “1”, “2”, and “Exit” or “3” if equipped. Refer to the Owner Manual for storing memory seat positions. Additionally, It is recommended to inform the vehicle owner that the stored memory positions may differ due to the servicing of the seat system. The K40D Driver Seat Adjuster Memory Module must be awake when measuring voltage from either one of the memory seat switch signal circuits. If the module is not fully awake incorrect voltage readings are possible and may result in misdiagnosing the circuit. The K40D Driver Seat Adjuster Memory Module must have seat positions stored to each position “1”, “2”, and “Exit” or “3” prior to that position recall functioning. Reference Information Driver Seat Schematics Connector End View Reference Master Electrical Component List Description and Operation Memory Seats 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/Vehicle in Service Mode.
  2. Verify that all power seat functions operate when being controlled by the S64D Front Seat Adjuster Switch – Driver. ⇒ If any manual power seat function does not operate Refer to Power Seat Malfunction ⇓ If all manual power seat functions operate
  3. Verify that all memory functions operate when being controlled by the S47D Front Seat Adjuster Memory Switch – Driver. ⇒ If any memory function does not operate Refer to Circuit/System Testing. ⇓ If all memory functions operate
  4. A fault is currently not present and may be an intermittent condition. Circuit/System Testing
  5. Ignition/Vehicle OFF, disconnect the connector at the S47D Front Seat Adjuster Memory Switch – Driver.
  6. Test for less than 10 Ω between the low reference circuit terminal 2 and ground. ⇒ If 10 Ω or greater 2.1. Test circuit 1151 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 2.2. Repair the open/high resistance in the ground connection. ⇓ If less than 10 Ω
  7. Ignition/Vehicle in Service Mode.
  8. Press a power seat switch, to wake up the K40D Driver Seat Adjuster Memory Module.
  9. Test for 9 V or greater between signal circuit terminal 4 and ground. ⇒ If less than 9 V 5.1. Test circuit 614 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 5.2. Test circuit 614 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 5.3. Replace the K40D Driver Seat Adjuster Memory Module. ⇓ If 9 V or greater
  10. Test for 4.8–5.2 Volts between signal circuit terminal 3 and ground. ⇒ If less than 4.8 V 6.1. Test circuit 615 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 6.2. Test circuit 615 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 6.3. Replace the K40D Driver Seat Adjuster Memory Module. ⇒ If greater than 5.2 V 6.1. Test circuit 615 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 K40D Driver Seat Adjuster Memory Module. ⇓ If between 4.8–5.2 V
  11. Ignition/Vehicle OFF, disconnect the connector X3 at the K40D Driver Seat Adjuster Memory Module.
  12. Ignition/Vehicle in Service Mode.
  13. Test for less than 1 V between signal circuit terminal 4 and ground. ⇒ If 1 V or greater Repair the short to voltage on the circuit 614. ⇓ If less than 1 V
  14. Test or replace the S47D Front Seat Adjuster Memory Switch – Driver. Component Testing Driver Seat Memory Switch
  15. Ignition/Vehicle OFF, disconnect the connector at the S47D Front Seat Adjuster Memory Switch – Driver.
  16. Test for infinite resistance between each signal terminal listed below and the ground terminal 2 with the switch in the open position. Terminal 3 Terminal 4 ⇒ If less than infinite resistance Replace the S47D Front Seat Adjuster Memory Switch – Driver. ⇓ If infinite resistance
  17. Test for less than 20 Ω between the signal terminal 4 and the ground terminal 2 while pressing the Memory SET button. ⇒ If 20 Ω or greater Replace the S47D Front Seat Adjuster Memory Switch – Driver. ⇓ If less than 20 Ω
  18. Test for 820–1070 Ω between the signal terminal 3 and the ground terminal 2 while pressing the Memory 1 button. ⇒ If not between 820–1070 Ω Replace the S47D Front Seat Adjuster Memory Switch – Driver. ⇓ If between 820–1070 Ω
  19. Test for 2330–3170 Ω between the signal terminal 3 and the ground terminal 2 while pressing the Memory 2 button. ⇒ If not between 2330–3170 Ω Replace the S47D Front Seat Adjuster Memory Switch – Driver. ⇓ If between 2330–31700 Ω
  20. Test for 5085–7615 Ω between the signal terminal 3 and the ground terminal 2 while pressing the Exit button. ⇒ If not between 5085–7615 Ω Replace the S47D Front Seat Adjuster Memory Switch – Driver. ⇓ If between 5085–7615 Ω
  21. All OK. Repair Instructions Perform the Diagnostic Repair Verification after completing the repair. Control Module References for K40D Driver Seat Adjuster Memory Module replacement, programming, and setup.