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Test Description

WARNING: This page is about a different car, the 2002 GMC Yukon XL, 2002 GMC Yukon, 2002 Chevrolet Tahoe, 2002 Chevrolet Suburban, and 2002 Chevrolet Avalanche. However, it is still accessible from the selected car via links, so may be relevant.

The numbers below refer to the step numbers on the diagnostic table.

  1. 2:  Tests to see if the malfunction is intermittent.
  2. 3:  Tests the internal resistance of the propshaft speed sensor.
  3. 4:  Tests to see if the propshaft speed sensor can generate a sufficient amount of AC voltage.
  4. 5:  Tests the FSS LO circuit for a short to ground, a high resistance, or an open.
  5. 6:  Tests the FSS HI circuit for a short to ground, a high resistance, or an open.
  6. 7:  Tests the FSS LO circuit for a short to voltage.
  7. 8:  Tests the FSS HI circuit for a short to voltage.
  8. 9:  Tests the FSS LO circuit for a short to the FSS HI circuit.
DTC C0305

Step Action Value(s) Yes No
Schematic Reference:  Transfer Case Control Schematics  
1 Was the Transfer Case Diagnostic System Check performed? - Go to Step 2  Go to Diagnostic System Check - Transfer Case 
2 
  1. Drive the vehicle for a short test drive.
  2. With the scan tool, observe the value of the Front Propshaft Speed data parameter in the Transfer Case data list.
Does the rpm value vary while driving?		 - Go to TESTING FOR INTERMITTENT AND POOR CONNECTIONS in Wiring Systems Go to Step 3 
3 
  1. Turn the ignition OFF.
  2. Disconnect the transfer case front propshaft speed sensor.
  3. Measure the resistance of the transfer case front propshaft speed sensor.
Is the resistance reading within the specified values?		 1300-2700 Ω Go to Step 4  Go to Step 10 
4 
  1. Connect a Digital Multimeter DMM to the transfer case front propshaft speed sensor.
  2. Block the rear wheels.
  3. Place the transmission in NEUTRAL.
  4. Raise and support the front axle so that the wheels turn freely.
  5. Hold one front wheel while rotating the other front wheel.
  6. Observing the AC voltage reading on the DMM.
Is the voltage reading greater than the specified value?		 0.5 V AC Go to Step 5  Go to Step 10 
5 
  1. Disconnect the transfer case shift control module.
  2. Test the FSS LO circuit for a short to ground, a high resistance, or an open. Refer to CIRCUIT TESTING and WIRING REPAIRS in Wiring Systems.
Was the condition found and corrected?		 - Go to Step 12  Go to Step 6 
6  Test the FSS HI circuit for a short to ground, a high resistance, or an open. Refer to CIRCUIT TESTING and WIRING REPAIRS in Wiring Systems.
Was the condition found and corrected?		 - Go to Step 12  Go to Step 7 
7  Test the FSS LO circuit for a short to voltage. Refer to CIRCUIT TESTING and WIRING REPAIRS in Wiring Systems.
Was the condition found and corrected?		 - Go to Step 12  Go to Step 8 
8  Test the FSS HI circuit for a short to voltage. Refer to CIRCUIT TESTING and WIRING REPAIRS in Wiring Systems.
Was the condition found and corrected?		 - Go to Step 12  Go to Step 9 
9  Test the FSS LO circuit for a short to the FSS HI circuit. Refer to CIRCUIT TESTING and WIRING REPAIRS in Wiring Systems.
Was the condition found and corrected?		 - Go to Step 12  Go to Step 11 
10 Replace the transfer case front propshaft speed sensor. Refer to Transfer Case Speed Sensor Replacement (Front)  or Transfer Case Speed Sensor Replacement (Right Rear)  or Transfer Case Speed Sensor Replacement (Left Rear) .
Is the repair complete?		 - Go to Step 12  -
11 Replace the transfer case shift control module. Refer to Transfer Case Shift Control Module Replacement .
Is the repair complete?		 - Go to Step 12  -
12
  1. Use the scan tool in order to clear the DTCs.
  2. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.
Does the DTC reset?		 - Go to Step 2  System OK
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