Component Testing

B109 Transfer Case Fluid Temperature Sensor

1. Ignition ON, engine OFF.
2. Record the value from the Transfer Case Fluid Temperature Sensor parameter.
3. Ignition OFF, disconnect the X1 harness connector at the B109 Transfer Case Fluid Temperature Sensor.
4. Ignition ON, engine OFF.
5. Verify the scan tool Transfer Case Fluid Temperature Sensor parameter displays -40°C/-40°F.
   • If the parameter does NOT display -40°C/-40°F 

     Refer to Circuit/System Testing.

   • If the parameter does display -40°C/-40°F 
6. Using a fused jumper, jump the 5 V reference circuit terminal A to the low reference circuit terminal B at the B109 Transfer Case Fluid Temperature sensor connector.
7. Verify the scan tool Calculated Transfer Case Clutch Temperature parameter displays 154°C/300°F.
   • If less than 154°C/300°F 

     Refer to Circuit/System Testing.

   • If greater than 154°C/300°F 

     Refer to Circuit/System Testing.

   • If 154°C/300°F 
NOTE:
• When test probing harness terminals, it is imperative to use the proper test probe from the most current version of the J 35616 GM-Approved Terminal Test Kit. Use of an improper test probe may deform the terminal, resulting in intermittent open conditions.
• Testing for Step 8 is performed on the B109 Transfer Case Fluid Temperature Sensor using the GY probe J 35616-3.
8. Test the resistance between the 5 V reference circuit, terminal A and the low reference circuit, terminal B. Refer to the Temperature Versus Resistance table below for the resistance values at various temperatures.
   • If the resistance is outside the specified range 

     Replace the B109 Transfer Case Fluid Temperature Sensor.

   • If the resistance is within the specified range 
9. B109 Transfer Case Fluid Temperature Sensor OK.