Ventilation Heat and Cool Module
WARNING: This page is about a different car, the 2009 GMC Sierra, 2009 GMC Cab & Chassis Sierra, 2009 Chevrolet Silverado, and 2009 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.
- Ignition OFF, disconnect the harness connectors at the seat cushion and seat back ventilation heat and cool modules.
- Test for 300 Ω - 18 kΩ between the temperature sensor signal circuit terminal 5 and the low reference circuit terminal 8.
- If not within the specified range, replace the ventilation heat and cool module.
- The test leads are incorrectly connected.
- Air blowing across the TED
- Measuring the resistance at other than room temperature of 70°F
- Holding the TED portion of the heated and cool ventilation module in your hand
- Test for 0.9 - 10.0 Ω between the heat control circuit terminal 1 and the cool control circuit terminal 3.
- If not within the specified range, replace the ventilation heat and cool module.
- Test for 6 k - 9 kΩ between blower motor control circuit terminal 2 and the low reference circuit terminal 4.
- If not within the specified range, replace the ventilation heat and cool module.
- Test for 290 k - 420 kΩ between blower motor speed control circuit terminal 7 and the low reference circuit terminal 4.
- If not within the specified range, replace the ventilation heat and cool module.
NOTE:
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 Ω ±5 percent. For warmer or cooler 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 Ω.
NOTE:
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 conditions listed below will change the resistance to out of range values:
In warmer or cooler 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.
In warmer or cooler 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.
NOTE:
The test leads must be connected in the correct polarity, otherwise higher out of range values will appear. Use the Positive Lead for the control circuit and the Negative Lead for the ground circuit.
NOTE:
The test leads need to be connected in the correct polarity, otherwise higher out of range values will appear. Use the Positive Lead for the speed control circuit and the Negative Lead for the ground circuit.
Temperature vs Resistance
| °C | °F | Resistance |
|---|---|---|
| Temperature vs Resistance Values (Approximate) | ||
| 60° | 140° | 319.9 Ω |
| 50° | 122° | 433.1 Ω |
| 40° | 104° | 596.6 Ω |
| 30° | 86° | 837.5 Ω |
| 20° | 68° | 1200 Ω |
| 10° | 50° | 1757 Ω |
| 0° | 32° | 2633 Ω |
| -10° | 14° | 4047 Ω |
| -20° | -4° | 6401 Ω |
| -30° | -22° | 10,450 Ω |
| -40° | -40° | 17,670 Ω |