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Home › Chevrolet › 2021 › Suburban Z71 › Repair and Diagnosis › Body & Frame › Windows › Fixed And MOVEABLE Window System › Diagnostic Information and Procedures › DTC B1953 › Circuit/System Testing

Circuit/System Testing

  1. Ignition/Vehicle & All vehicle systems - Off
  2. Disconnect the electrical connector: M74P Front Side Door Window Regulator Motor-Passenger
  3. Connect a test lamp between the test points: Signal circuit terminal 3 & B+
  4. Ignition - On / Vehicle - In Service Mode
  5. Operate the component: S79P Front Side Door Window Switch-Passenger - Pulled

    Verify the test lamp state:

    S79P Front Side Door Window Switch-Passenger - Not Used = Test lamp Off

    S79P Front Side Door Window Switch-Passenger - Pulled = Test lamp On

    • If the test lamp is always OFF 
    1. Ignition OFF, remove the test lamp, disconnect the harness connector at the S79P Front Side Door Window Switch-Passenger
    2. Test for infinite resistance between the signal 1184 and ground.
      • If less than infinite resistance, repair the short to ground on the circuit.
      • Go to next step: If infinite resistance
    3. Test for less than 2 Ω in the signal 1184 end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, replace the S79P Front Side Door Window Switch-Passenger
    • If the test lamp is always ON 
    1. Ignition OFF, remove the test lamp, disconnect the harness connector at the S79P Front Side Door Window Switch-Passenger ignition ON.
    2. Test for less than 1 V between the signal 1184 and ground.
      • If 1 V or greater, repair the short to voltage on the circuit.
      • If less than 1 V, replace the S79P Front Side Door Window Switch-Passenger
    • Go to next step: If the test lamp turns ON and OFF 
  6. Connect a test lamp between the test points: Signal circuit terminal 7 & B+
  7. Ignition - On / Vehicle - In Service Mode
  8. Operate the component: S79P Front Side Door Window Switch-Passenger - Pressed

    Verify the test lamp state:

    S79P Front Side Door Window Switch-Passenger - Not Used = Test lamp Off

    S79P Front Side Door Window Switch-Passenger - Pressed = Test lamp On

    • If the test lamp is always OFF 
    1. Ignition OFF, remove the test lamp, disconnect the harness connector at the S79P Front Side Door Window Switch-Passenger
    2. Test for infinite resistance between the signal 5295 and ground.
      • If less than infinite resistance, repair the short to ground on the circuit.
      • Go to next step: If infinite resistance
    3. Test for less than 2 Ω in the signal 5295 end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, replace the S79P Front Side Door Window Switch-Passenger
    • If the test lamp is always ON 
    1. Ignition OFF, remove the test lamp, disconnect the harness connector at the S79P Front Side Door Window Switch-Passenger, ignition ON.
    2. Test for less than 1 V between the signal 5295 and ground.
      • If 1 V or greater, repair the short to voltage on the circuit.
      • If less than 1 V, replace the S79P Front Side Door Window Switch-Passenger.
    • Go to next step: If the test lamp turns ON and OFF 
  9. Connect a test lamp between the test points: Signal circuit terminal 5 & B+
  10. Ignition - On / Vehicle - In Service Mode
  11. Operate the component: S79P Front Side Door Window Switch-Passenger - Pressed & Pulled

    Verify the test lamp state:

    S79P Front Side Door Window Switch-Passenger - Not Used = Test lamp Off

    S79P Front Side Door Window Switch-Passenger - Pressed = Test lamp On

    S79P Front Side Door Window Switch-Passenger - Pulled = Test lamp On

    • If the test lamp is always OFF 
    1. Ignition OFF, remove the test lamp, disconnect the harness connector at the S79P Front Side Door Window Switch-Passenger
    2. Test for infinite resistance between the signal 2765 and ground.
      • If less than infinite resistance, repair the short to ground on the circuit.
      • Go to next step: If infinite resistance
    3. Test for less than 2 Ω in the signal 2765 end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, replace the S79P Front Side Door Window Switch-Passenger
    • If the test lamp is always ON 
    1. Ignition OFF, remove the test lamp, disconnect the harness connector at the S79P Front Side Door Window Switch-Passenger, ignition ON.
    2. Test for less than 1 V between the signal 2765 and ground.
      • If 1 V or greater, repair the short to voltage on the circuit.
      • If less than 1 V, replace the S79P Front Side Door Window Switch-Passenger.
    • Go to next step: If the test lamp turns ON and OFF 
  12. Test or replace the component: M74P Front Side Door Window Regulator Motor-Passenger
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