B2425 0A, B2425 0B, B2425 0C, B2425 0D, B2425 0E, B2425 04, or B2425 1F
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 X3 harness connector at the MSM.
- Ignition ON, verify that a test lamp illuminates between the B+ circuit terminal 5 and ground.
- If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance.
- Ignition OFF, connect the X3 harness connector at the MSM and disconnect the X1 harness connector at the MSM.
- Test for 2.0-8.0 ohms between control circuit terminal 14 and control circuit terminal 11.
- If greater than the specified range, test the control circuits for an open/high resistance. If the circuits test normal replace the seat cushion heater element.
- If less than the specified range, test for a short between the control circuits. If the circuits test normal, replace the seat cushion heater element.
- Disconnect the X2, X5 harness connectors at the MSM.
- Test for 850-300K ohms between the signal circuit terminal 1 X5 and the low reference circuit terminal 3 X2.
- If greater than the specified range, test the signal and low reference circuits for a short to voltage or an open/high resistance. If the circuits test normal, replace the seat cushion heater element/temperature sensor.
- If less than the specified range, test for a short between the signal and low reference circuits. If the circuits test normal, replace the seat cushion heater element/temperature sensor.
- Connect the X1, X2, X5 harness connectors at the MSM.
- Disconnect the harness connector at the seat cushion heater element/temperature sensor.
- Ignition ON, test for 4.8-5.2 volts between the signal circuit terminal C and ground.
- If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the MSM.
- If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the MSM.
- If all circuits test normal, replace the MSM.
IMPORTANT:
When measuring the resistance, the resistance values are based on the seat being at room temperature of 20°C (68°F).