Lucerne V6-3.8L (2007)
Connect a test lamp between the following circuits and ground. The test lamp should illuminate or slowly illuminate for approximately 5 seconds
after pressing the HEAT switch.
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Terminal 2 seat back blower motor supply voltage circuit
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Terminal 7 seat back blower motor speed control circuit
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If the test lamp does not illuminate, test the appropriate circuit for an open/high resistance. If the circuit tests normal, replace the CCS module.
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If the test lamp is always ON, test the appropriate circuit for a short to voltage. If the circuit tests normal, replace the CCS module.
20. If all circuits test normal, test or replace the appropriate ventilation heat and cool module.
Passenger Heated/Cooled Seat Inoperative
1. Ignition ON, observe the following scan tool parameters in the Passenger Door Switch data list while pressing and releasing the related switch.
The readings should change between Active and Inactive.
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Seat Back Heat Mode Sw.
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Seat Cool Mode Switch
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Seat Heat Mode Sw.
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If not Active or always Active, perform the Heated and Cooled Seat Switch Component Test. See: Seat Heater Switch/Diagrams
2. Ignition OFF, disconnect the (C1, C2, C3) harness connectors at the CCS module.
3. Connect a test lamp between the heated/cooled seat mode signal circuit terminal 6 (C3) and battery voltage.
4. Ignition ON, press the HEAT or COOL switch through the high, medium, and low positions to OFF. The test lamp should illuminate until the OFF
position is reached.
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If the test lamp does not illuminate, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace
the MSM.
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If the test lamp is ON with the switch in the OFF position, test the signal circuit for a short to ground. If the circuit tests normal, replace the
MSM.
5. IMPORTANT: If the resistance is measured with the seat still warm or cool, the resistance values will vary. At 68°F (20°C), the nominal
resistance value is 1200 ohms ±5 percent. For hotter or colder ambient temperatures, refer to the Temperature vs Resistance table below. The
delta resistance values between the seat cushion and seat back temperature sensors should not be greater than 2000 ohms.
Test for 300 - 18K ohms of resistance between the following temperature sensor signal and low reference circuits. The resistance should measure
near the specified value in the Temperature vs Resistance table below.
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Connector C2 seat cushion temperature sensor signal circuit terminal 2 and low reference circuit terminal 3.
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Connector C2 seat back temperature sensor signal circuit terminal 4 and low reference circuit terminal 5.
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If the resistance is greater than the specified value, test the sensor signal circuit and low reference circuit for a short to voltage or an open/high
resistance. If the circuits test normal, test or replace the appropriate ventilation heat and cool module.
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If the resistance measures less than the specified value, test or replace the appropriate ventilation heat and cool module.
6. IMPORTANT: The test leads must be connected in the correct polarity, otherwise lower out of range values will appear. Use the Positive Lead
for the COOL control circuit and the Negative Lead for the HEAT control circuit. If the resistance is measured with the seat still warm or cool, the
resistance values will vary even if the system was powered up for just a few seconds. The TED must be allowed to stabilize to room temperature
prior to a measurement. The following conditions will change the resistance to out of range values:
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The test leads are incorrectly connected
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Air blowing across the TED.
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Measuring the resistance at other than room temperature of 70°F (21°C).
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Holding the TED portion of the heated and cool ventilation module in your hand.
In hotter or colder climates where room temperature conditions of 70°F (21°C) may be unattainable, resistance values may read above the
specified range. Use a heat gun or a blower to warm or cool the TED while measuring the resistance. The resistance values should slowly lower
toward the specified range.
Test for 0.9-10 ohms of resistance between the following heat control and cool control circuits.
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Connector C1 seat cushion heat control circuit terminal A and cool control circuit terminal B.
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Connector C1 seat back heat control circuit terminal C and cool control circuit terminal D.
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If greater than 10 ohms, test the control circuits for an open/high resistance. If the circuits test normal, test or replace the appropriate
ventilation heat and cool module.
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If less than 0.9 ohms, test or replace the appropriate ventilation heat and cool module.
7. Test for infinite resistance between the following circuits and ground.
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Connector C1:
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Seat cushion heat control circuit terminal A
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Seat cushion cool control circuit terminal B
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Seat back heat control circuit terminal C
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Seat back cool control circuit terminal D
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Connector C2:
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Seat cushion temperature sensor signal circuit terminal 2
