LEMON Manuals: Even more car manuals for everyone
Home >> Hummer >> 2008 >> H2 4D Utility Wagon >> Repair and Diagnosis >> External Pages >> Different car >> Section 207 (Seat Heating System & Seat Cooling System) >> Diagnostic Information and Procedures >> DTC B2435 or B2440 (Without Memory, With HP2) >> Circuit/System Testing

Circuit/System Testing

WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 2008 GMC Yukon XL, 2008 GMC Yukon, 2008 Chevrolet Tahoe, 2008 Chevrolet Suburban, and 2008 Chevrolet Avalanche. However, it is still accessible from the selected car via links, so may be relevant.

B2435 02 or B2435 05

  1. Ignition OFF, disconnect the X2, X4 harness connectors at the HSM.
    2. IMPORTANT: When measuring the resistance, the resistance values are based on the seat being at room temperature of 20°C (68°F).
  2. Test for 850-300K ohms between the signal circuit terminal 19 X4 and the low reference circuit terminal 5 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 back 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 back heater element/temperature sensor.
  3. Connect the X2, X4 harness connectors at the HSM.
  4. Disconnect the harness connector at the seat back heater element/temperature sensor.
  5. 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 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.
  6. If all circuits test normal, replace the HSM.

B2440 02 or B2440 05

  1. Ignition OFF, disconnect the X2, X4 harness connectors at the HSM.
    2. IMPORTANT: When measuring the resistance, the resistance values are based on the seat being at room temperature of 20°C (68°F).
  2. Test for 850-300K ohms between the signal circuit terminal 10 X4 and the low reference circuit terminal 7 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 back 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 back heater element/temperature sensor.
  3. Connect the X2, X4 harness connectors at the HSM.
  4. Disconnect the harness connector at the seat back heater element/temperature sensor.
  5. 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 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.
  6. If all circuits test normal, replace the HSM.
scientia non olet · About LEMON Manuals