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Tahoe / Yukon Service Manual

DTC B1952

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 B1952 Driver Window Switch Symptom Byte Information: Symptom Byte List Diagnostic Fault Information

Circuit Number Circuit Function Short to Ground Open/High Resistance Short to Voltage Signal Performan
2763 Signal B1952 11 1 1 —
2764 Signal B1952 11 1 1 —
2766 Signal B1952 11 1 1 —
1. M74D Front Side Door Window Regulator Motor-Driver= Inoperative

Circuit/System Description The window motors supply 12V signal circuits to their respective window switches, when a window switch has been activated, a switch closes providing a ground to the appropriate signal circuit causing the voltage to drop to 0V. The window motor will detect the voltage drop in the signal circuit and will command the window to move in the desired direction. The driver window control switch also contains control switches for the passenger, left rear and right rear window functions. When a window switch is pressed, a serial data message is sent to the body control module (BCM). The BCM examines the request and checks for messages from other power window motors that may prohibit window movement. If no prohibitive messages have been received, the BCM will send a serial data message to the passenger window motor or to the appropriate rear window motor which will perform the command as requested. Conditions for Running the DTC Vehicle = All power modes Voltage between 10–16 V Conditions for Setting the DTC B1952 11 2763= Short to Ground — For greater than 60 s g 2764= Short to Ground — For greater than 60 s 2766= Short to Ground — For greater than 60 s B1952 49 S79D Front Side Door Window Control Switch-Driver= Internal Malfunction B1952 96 S79D Front Side Door Window Control Switch-Driver= Component Internal Malfunction Actions Taken When the DTC Sets S79D Front Side Door Window Control Switch-Driver— The driver window motor may be inoperative or may be inoperative in the up function, the down function or the express functions from the driver window switch. Conditions for Clearing the DTC B1952 11 A current DTC will clear when the diagnostic runs and passes. A history DTC will clear after 40 consecutive malfunction-free ignition cycles. B1952 49, B1952 96 If set as a current DTC » Replace the component: S79D Front Side Door Window Control Switch- Driver Reference Information Schematic Reference Moveable Window Schematics Connector End View Reference Master Electrical Component List Description and Operation Power Windows 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. Vehicle Power Mode » Run/Service Mode.
  2. Operate the component: Driver Left Front Window Switch @ S79D Front Side Door Window Control Switch-Driver» Pressed & Pulled Verify the component works as specified: M74D Front Side Door Window Regulator Motor-Driver = Up M74D Front Side Door Window Regulator Motor-Driver = Express Up M74D Front Side Door Window Regulator Motor-Driver = Down M74D Front Side Door Window Regulator Motor-Driver = Express Down ⇒ If the component does not work as specified Refer to: Circuit/System Testing ⇓ If the component works as specified
  3. A fault that is not currently present may have been caused by a intermittent condition. Circuit/System Testing
  4. Vehicle Power Mode » Off.
  5. Disconnect the electrical connector: X1 @ M74D Front Side Door Window Regulator Motor- Driver.
  6. Connect a test lamp between the test points: Signal circuit terminal 3 & B+.
  7. Vehicle Power Mode » Run/Service Mode.
  8. Operate the component: Driver Left Front Window Switch @ S79D Front Side Door Window Control Switch-Driver» Pulled Verify the test lamp state: Driver Left Front Window Switch » Not Used = Test lamp Off Driver Left Front Window Switch » Pulled = Test lamp On ⇒ If the test lamp is always OFF 5.1. Vehicle Power Mode » Off. 5.2. Remove the test lamp, disconnect the X1 harness connector at the S79D Front Side Door Window Control Switch-Driver. 5.3. Test for less than 2 Ω in the circuit 2763 end to end. ⇒ If 2 Ω or greater, repair the open/high resistance in the circuit. ⇓ If less than 2 Ω. 5.4. Vehicle Power Mode » Run/Service Mode. 5.5. Test for less than 1 V between the circuit 2763 and ground. ⇒ If 1 V or greater, repair the short to voltage on the circuit. ⇒ If less than 1 V, replace the S79D Front Side Door Window Control Switch-Driver. ⇒ If the test lamp is always ON 5.1. Vehicle Power Mode » Off. 5.2. Remove the test lamp, disconnect the X1 harness connector at the S79D Front Side Door Window Control Switch-Driver. 5.3. Test for infinite resistance between the circuit 2763 and ground. ⇒ If less than infinite resistance, repair the short to ground on the circuit. ⇒ If infinite resistance, replace the S79D Front Side Door Window Control Switch-Driver ⇓ If the test lamp turns ON and OFF
  9. Connect a test lamp between the test points: Signal circuit terminal 7 & B+.
  10. Vehicle Power Mode » Run/Service Mode.
  11. Operate the component: Driver Left Front Window Switch @ S79D Front Side Door Window Control Switch-Driver» Pressed Verify the test lamp state: Driver Left Front Window Switch » Not Used = Test lamp Off Driver Left Front Window Switch » Pressed = Test lamp On ⇒ If the test lamp is always OFF 8.1. Vehicle Power Mode » Off. 8.2. Remove the test lamp, disconnect the X1 harness connector at the S79D Front Side Door Window Control Switch-Driver. 8.3. Test for less than 2 Ω in the circuit 2764 end to end. ⇒ If 2 Ω or greater, repair the open/high resistance in the circuit. ⇓ If less than 2 Ω. 8.4. Vehicle Power Mode » Run/Service Mode. 8.5. Test for less than 1 V between the circuit 2764 and ground. ⇒ If 1 V or greater, repair the short to voltage on the circuit. ⇒ If less than 1 V, replace the S79D Front Side Door Window Control Switch-Driver. ⇒ If the test lamp is always ON 8.1. Vehicle Power Mode » Off. 8.2. Remove the test lamp, disconnect the X1 harness connector at the S79D Front Side Door Window Control Switch-Driver. 8.3. Test for infinite resistance between the circuit 2764 and ground. ⇒ If less than infinite resistance, repair the short to ground on the circuit. ⇒ If infinite resistance, replace the S79D Front Side Door Window Control Switch-Driver ⇓ If the test lamp turns ON and OFF
  12. Connect a test lamp between the test points: Signal circuit terminal 5 & B+.
  13. Vehicle Power Mode » Run/Service Mode.
  14. Operate the component: Driver Left Front Window Switch @ S79D Front Side Door Window Control Switch-Driver» Pressed & Pulled Verify the test lamp state: Driver Left Front Window Switch » Not Used = Test lamp Off Driver Left Front Window Switch » Pressed = Test lamp On Driver Left Front Window Switch » Pulled = Test lamp On ⇒ If the test lamp is always OFF 11.1. Vehicle Power Mode » Off. 11.2. Remove the test lamp, disconnect the X2 harness connector at the S79D Front Side Door Window Control Switch-Driver. 11.3. Test for less than 2 Ω in the circuit 2766 end to end. ⇒ If 2 Ω or greater, repair the open/high resistance in the circuit. ⇓ If less than 2 Ω. 11.4. Vehicle Power Mode » Run/Service Mode. 11.5. Test for less than 1 V between the circuit 2766 and ground. ⇒ If 1 V or greater, repair the short to voltage on the circuit. ⇒ If less than 1 V, replace the S79D Front Side Door Window Control Switch-Driver. ⇒ If the test lamp is always ON 11.1. Vehicle Power Mode » Off. 11.2. Remove the test lamp, disconnect the X2 harness connector at the S79D Front Side Door Window Control Switch-Driver. 11.3. Test for infinite resistance between the circuit 2766 and ground. ⇒ If less than infinite resistance, repair the short to ground on the circuit. ⇒ If infinite resistance, replace the S79D Front Side Door Window Control Switch-Driver ⇓ If the test lamp turns ON and OFF
  15. Test or replace the component: M74D Front Side Door Window Regulator Motor-Driver. Repair Instructions Perform the Diagnostic Repair Verification after completing the repair: Diagnostic Repair Verification Front Side Door Window Regulator Replacement Front Side Door Window Control Switch Replacement