Circuit/System Testing
WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 2012 GMC Yukon XL, 2012 GMC Yukon, 2012 Chevrolet Tahoe, 2012 Chevrolet Suburban, and 2012 Chevrolet Avalanche. However, it is still accessible from the selected car via links, so may be relevant.
B2425 0A, B2425 0B, B2425 0C, B2425 0D, B2425 0E, B2425 04, or B2425 1F
- Ignition OFF, disconnect the X1 harness connector at the HSM.
- Test for 2.0 - 8.0 Ω between control circuit terminal 3 and control circuit terminal 5.
- 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.
- 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.
- Disconnect the X2, X4 harness connectors at the HSM.
- Test for 850 Ω - 300 kΩ between the signal circuit terminal 9 X4 and the low reference circuit terminal 6 X2.
- 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.
- 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.
- Connect the X1, X2, X4 harness connectors at the HSM.
- Disconnect the harness connector at the seat cushion heater element/temperature sensor.
- Ignition ON, test for 4.8 - 5.2 V 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 HSM.
- 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 HSM.
- If all circuits test normal, replace the HSM.
IMPORTANT:
Element resistance must be measured twice to ensure that all failure conditions are simulated. First with the seat unoccupied, then with the seat occupied.
B2430 0A, B2430 0B, B2430 0C, B2430 0D, B2430 0E, B2430 04, or B2430 1F
- Ignition OFF, disconnect the X1 harness connector at the HSM.
- Test for 2.0 - 8.0 Ω between control circuit terminal 6 and control circuit terminal 2.
- 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.
- 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.
- Disconnect the X2, X4 harness connectors at the HSM.
- Test for 850 Ω - 300 kΩ between the signal circuit terminal 20 X4 and the low reference circuit terminal 8 X2.
- 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.
- 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.
- Connect the X1, X2, X4 harness connectors at the HSM.
- Disconnect the harness connector at the seat cushion heater element/temperature sensor.
- Ignition ON, test for 4.8 - 5.2 V between the signal circuit terminal C and ground.
- 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 HSM.
- If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the HSM.
- If all circuits test normal, replace the HSM.
IMPORTANT:
Element resistance must be measured twice to ensure that all failure conditions are simulated. First with the seat unoccupied, then with the seat occupied.