Land Rover Repair: 03 Range Rover Fault Code, obd ii scanner, mass air meter

Question
I have an 03 Range Rover, I have been getting a TRAN FAILSAFE PROGRAM in the message center. Sometimes when this code comes up the transmission feels weak, if I am on the highway my rpms run higher then normal. Once I turn the auto off the message usually goes away, even it it stays the transmission goes back to operating normally again. Sometimes the checkengine light will come on for about a half a day then will all of a sudden go away.

The test was run on the OB2? orange tester and it read p0721 output speed sensor circuit range perf, and also transmission fault. Can you tell me what you think it might be? Thanks

Answer
More tests would be required to get to the bottom of your problem, and those tests are beyond the scope of a generic OBD II scanner.  I suggest you find someone with a Land Rover test system - Autologic, IDS or T4 - and check the transmission and its controls.

Sometimes those speed sensor faults relate to issues with the sensors but other times they relate to internal gearbox problem and even external stuff like mass air meter failures on the motor.