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Home >> Cadillac >> 2021 >> CT4 Sport, RWD >> Repair and Diagnosis >> External Pages >> Different car >> Section 110 (Seat Heating And Cooling) >> Diagnostic Information and Procedures >> Front Heated Seat Malfunction >> Circuit/System Testing

Circuit/System Testing

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Both Heated Seats are Inoperative

    NOTE:

    Circuit/System Verification must be performed before proceeding with Circuit/System Testing.

  1. Ignition OFF, disconnect the X1 harness connector at the K29F Front Seat Heater Control Module, ignition ON.
  2. Verify a test lamp illuminates between each B+ circuit terminals listed below and ground.
    • Terminal 7
    • Terminal 10
    • If the test lamp does not illuminate and the circuit fuse is good 
    1. Ignition OFF, remove the test lamp.
    2. Test for less than 2 Ω in the B+ circuit end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, verify the fuse is OK and there is voltage at the fuse.
    • If the test lamp does not illuminate and the circuit fuse is open 
    1. Ignition OFF, remove the test lamp.
    2. Test for infinite resistance between the B+ circuit and ground.
      • If less than infinite resistance, repair the short to ground on the circuit.
      • If infinite resistance, replace the K29F Front Seat Heater Control Module.
    • Go to next step: If the test lamp illuminates 
  3. Ignition OFF.
  4. Test for infinite resistance between each control circuit terminal listed below and ground, one at a time.
    • Terminal 2
    • Terminal 6
    • If less than infinite resistance 

      Repair the short to ground on the circuit.

    • Go to next step: If infinite resistance 
  5. Ignition ON.
  6. Test for less than 1 V between each control circuit terminal listed below and ground, one at a time.
    • Terminal 2
    • Terminal 6
    • If 1 V or greater 

      Repair the short to voltage on the circuit.

    • Go to next step: If less than 1 V 
  7. Replace the K29F Front Seat Heater Control Module.

One Heated Seat is Inoperative

    NOTE:

    Circuit/System Verification must be performed before proceeding with Circuit/System Testing

  1. Ignition OFF, disconnect the X1 harness connector at the K29F Front Seat Heater Control Module, ignition ON.
  2. Verify a test lamp illuminates between the B+ circuit terminal 7 and ground.
    • If the test lamp does not illuminate and the circuit fuse is good 
    1. Ignition OFF, remove the test lamp
    2. Test for less than 2 Ω in the B+ circuit end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, verify the fuse is OK and there is voltage at the fuse.
    • If the test lamp does not illuminate and the circuit fuse is open 
    1. Ignition OFF, remove the test lamp.
    2. Test for infinite resistance between the B+ circuit and ground.
      • If less than infinite resistance, repair the short to ground on the circuit.
      • If infinite resistance, replace the K29F Front Seat Heater Control Module.
    • Go to next step: If the test lamp illuminates 
  3. Ignition OFF, connect the X1 harness connector at the K29F Front Seat Heater Control Module. Disconnect the harness connector at the E14 Seat Heating Element - Cushion and the E14 Seat Heating Element - Back, ignition ON.
    4. NOTE:

    When performing this test ensure that you are testing from the correct terminal. Testing from the incorrect terminal will cause a misdiagnosis of the circuit. Three of the four terminals in this connector will not only display a voltage reading but a different voltage reading.

  4. Test for 4.8 - 5.2 V between each signal circuit terminal listed below and ground, one at a time.
    • E14 Seat Heating Element - Cushion terminal 2
    • E14 Seat Heating Element - Back terminal 2
    • If less than 4.8 V 
    1. Ignition OFF, disconnect the X2 harness connector at the K29F Front Seat Heater Control Module.
    2. Test for infinite resistance between the signal circuit 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 circuit end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, replace the K29F Front Seat Heater Control Module.
    • If greater than 5.2 V 
    1. Ignition OFF, disconnect the X2 harness connector at the K29F Front Seat Heater Control Module, ignition ON.
    2. Test for less than 1 V between the signal circuit and ground.
      • If 1 V or greater, repair the short to voltage on the circuit.
      • If less than 1 V, replace the K29F Front Seat Heater Control Module.
    • Go to next step: If between 4.8 - 5.2 V 
  5. Connect a test lamp between control circuit terminal 1 and control circuit terminal 4 of the E14 Seat Heating Element - Back, engine ON.
    6. NOTE:

    The test lamp should turn ON for approximately 10 s after the heated seat is commanded ON.

  6. Verify the test lamp turns ON after pressing the heated seat switch.
    • If the test lamp is always OFF 
    1. Ignition OFF, remove the test lamp, disconnect the X1 harness connector at the K29F Front Seat Heater Control Module.
    2. Test for less than 2 Ω in each control circuit end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, replace the K29F Front Seat Heater Control Module.
    • Go to next step: If the test lamp turns ON 
  7. Ignition OFF, connect the harness connector at the E14 Seat Heating Element - Cushion, ignition ON.
  8. Verify the test lamp turns ON after pressing the heated seat switch.
    • If the test lamp is always OFF 
      NOTE:

      Because of the type of material used in the heater element, a reliable resistance value is unavailable for a component test.

      Test or replace the E14 Seat Heating Element - Cushion.

    • Go to next step: If the test lamp turns ON 
    9. NOTE:

    Because of the type of material used in the heater element, a reliable resistance value is unavailable for a component test.

  9. Test or replace the E14 Seat Heating Element - Back.

One Heating Element is Inoperative

    NOTE:

    Circuit/System Verification must be performed before proceeding with Circuit/System Testing.

  1. Ignition OFF, disconnect the harness connector at the appropriate E14 Seat Heating Element.
  2. Connect a test lamp between control circuit terminal 1 and control circuit terminal 4, engine ON.
  3. Verify the test lamp turns ON after pressing the heated seat switch.
    • If the test lamp is always OFF 
    1. Ignition OFF, remove the test lamp, disconnect the X1 harness connector at the K29F Front Seat Heater Control Module.
    2. Test for less than 2 Ω in each control circuit end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
    • Go to next step: If the test lamp turns ON 
    4. NOTE:

    Because of the type of material used in the heater element, a reliable resistance value is unavailable for a component test.

  4. Test or replace the E14 Seat heating Element.

Degraded Heated Seat Operation Driver Seat

    NOTE:

    Circuit/System Verification must be performed before proceeding with Circuit/System Testing

  1. Ignition OFF, disconnect the harness connector at each component listed below. It may take up to 2 min for all vehicle systems to power down.
    • E14A Seat Heating Element - Driver Back
    • E14B Seat Heating Element - Driver Cushion
  2. Test for less than 40 Ω between each low reference circuit terminal listed below and ground, one at a time.
    • E14A Seat Heating Element - Driver Back terminal 3
    • E14B Seat Heating Element - Driver Cushion terminal 3
    • If 40 Ω or greater 
    1. Ignition OFF, disconnect the X2 harness connector at the K29F Front Seat Heater Control Module.
    2. Test for less than 2 Ω in the low reference circuit end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, replace the K29F Front Seat Heater Control Module.
    • Go to next step: If less than 40 Ω 
  3. Ignition ON.
  4. Test for 4.8 - 5.2 V between each signal circuit terminal listed below and ground, one at a time.
    • E14A Seat Heating Element - Driver Back terminal 2
    • E14B Seat Heating Element - Driver Cushion terminal 2
    • If less than 4.8 V 
    1. Ignition OFF, disconnect the X2 harness connector at the K29F Front Seat Heater Control Module.
    2. Test for infinite resistance between the signal circuit 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 circuit end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, replace the K29F Front Seat Heater Control Module.
    • If greater than 5.2 V 
    1. Ignition OFF, disconnect the X2 harness connector at the K29F Front Seat Heater Control Module, ignition ON.
    2. Test for less than 1 V between the signal circuit and ground.
      • If 1 V or greater, repair the short to voltage on the circuit.
      • If less than 1 V, replace the K29F Front Seat Heater Control Module.
    • Go to next step: If between 4.8 - 5.2 V 
  5. Ignition OFF, connect the harness connector at the E14B Seat Heating Element - Driver Cushion and the E14A Seat Heating Element - Driver Back. Disconnect the X2 harness connector at the K29F Front Seat Heater Control Module.
  6. Test for 500 Ω - 300 kΩ between the signal circuit and the low reference circuit terminals listed below, one at a time.
    • E14A Seat Heating Element - Driver Back terminal 3 and terminal 1
    • E14B Seat Heating Element - Driver Cushion terminal 6 and terminal 1
    • If not between 500 Ω - 300 kΩ 

      Replace the E14 Seat Heating Element.

    • Go to next step: If between 500 Ω - 300 kΩ 
  7. Replace the K29F Front Seat Heater Control Module.

Degraded Heated Seat Operation Passenger Seat

    NOTE:

    Circuit/System Verification must be performed before proceeding with Circuit/System Testing

  1. Ignition OFF, disconnect the harness connector at each component listed below. It may take up to 2 min for all vehicle systems to power down.
    • E14C Seat Heating Element - Passenger Back
    • E14D Seat Heating Element - Passenger Cushion
  2. Test for less than 40 Ω between each low reference circuit terminal listed below and ground, one at a time.
    • E14C Seat Heating Element - Passenger Back terminal 3
    • E14D Seat Heating Element - Passenger Cushion terminal 3
    • If 40 Ω or greater 
    1. Ignition OFF, disconnect the X2 harness connector at the K29F Front Seat Heater Control Module.
    2. Test for less than 2 Ω in the low reference circuit end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, replace the K29F Front Seat Heater Control Module.
    • Go to next step: If less than 40 Ω 
  3. Ignition ON.
  4. Test for 4.8 - 5.2 V between each signal circuit terminal listed below and ground, one at a time.
    • E14C Seat Heating Element - Passenger Back terminal 2
    • E14D Seat Heating Element - Passenger Cushion terminal 2
    • If less than 4.8 V 
    1. Ignition OFF, disconnect the X2 harness connector at the K29F Front Seat Heater Control Module.
    2. Test for infinite resistance between the signal circuit 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 circuit end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, replace the K29F Front Seat Heater Control Module.
    • If greater than 5.2 V 
    1. Ignition OFF, disconnect the X2 harness connector at the K29F Front Seat Heater Control Module, ignition ON.
    2. Test for less than 1 V between the signal circuit and ground.
      • If 1 V or greater, repair the short to voltage on the circuit.
      • If less than 1 V, replace the K29F Front Seat Heater Control Module.
    • Go to next step: If between 4.8 - 5.2 V 
  5. Ignition OFF, connect the harness connector at the E14D Seat Heating Element - Passenger Cushion and the E14C Seat Heating Element - Passenger Back. Disconnect the X2 harness connector at the K29F Front Seat Heater Control Module.
  6. Test for 500 Ω - 300 kΩ between the signal circuit and the low reference circuit terminals listed below, one at a time.
    • E14C Seat Heating Element - Passenger Back terminal 4 and terminal 12
    • E14D Seat Heating Element - Passenger Cushion terminal 5 and terminal 2
    • If not between 500 Ω - 300 kΩ 

      Replace the E14 Seat Heating Element.

    • Go to next step: If between 500 Ω - 300 kΩ 
  7. Replace the K29F Front Seat Heater Control Module.
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