LEMON Manuals: Even more car manuals for everyone
Home >> Cadillac >> 2021 >> CT4 Sport, 4WD >> Repair and Diagnosis >> External Pages >> Different car >> Section 110 (Seat Heating And Cooling) >> Diagnostic Information and Procedures >> DTC B12CC, B1338, B1339, or B133A >> Circuit/System Testing

Circuit/System Testing

WARNING: This page is about a different car, the 2022 Cadillac CT4. However, it is still accessible from the selected car via links, so may be relevant.

B12CC or B1338

    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.

B1339 or B133A

    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.
scientia non olet · About LEMON Manuals