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P0721 Diagnostic Trouble Code Discussion for August 2010

Output Shaft Speed Sensor Circuit Malfunction


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Trouble Ticket Help Requests for DTC P0721
Help Request Posted
2003 GMC Sierra 2500 HD 6.6L MIL Lamp on VIN: 1GCHK23123
P0721: Output Speed Sensor Performance. Greeting fellow techs. This truck has had this problem for almost 1 year now. It is very intermittent- have never had it happen on test drives etc. At first the vss in the transfer case was replaced and the transfer case was rebuilt. Problem still came back. W...
August 27, 2010
2003 GMC Sierra 2500 HD 6.6L MIL Lamp on VIN: 1GCHK23123
P0721: Output Speed Sensor Performance. Greeting fellow techs. This truck has had this problem for almost 1 year now. It is very intermittent- have never had it happen on test drives etc. At first the vss in the transfer case was replaced and the transfer case was rebuilt. Problem still came back. W...
August 27, 2010