XC 70 2001 "transmission service required"

[volvodadvt]

While driving down the road I heard a loud hud and the "transmission service required" and check engine light came on. The codes (as per Auto Zone) are 0717 and 0716. I was told that this is a module for transmission and that it is okay to drive the car and that it will not stop, just have problems in the low gears and require you to start in 3rd gear. At that point (I am told by a friend familiar with Volvo repairs) it should be fixed. I have driven the car several times since the incident and the thud happens once each time (seems like when downshifting at 40-50 mph). Is this advice correct?

Also, the clock has a minus sign in front of it and the compartment fan is no longer blowing. These two event happened after the initial thud. Just a coincidence or are they possibly related?

Is this type of problem something a person with basic mechanic skills (with guidance) can address or does it require a Volvo specialist? I would prefer to save money on a repair if possible, but getting it done right is more importan.

Thanks.

[JDS60R]

You should head to a quality transmission shop. It could be as simple as the failure of a solenoid in the trans.

If your volvo specialist and quality trans shop charge the same then I would go with the specialist.

To do this yourself you would need a diagnostic reader that can read trans codes ($200 unless you know someone who has one) .

Once you find the codes - if its just a solenoid you could replace it yourself if you are comfortable working with transmissions. If you do not have a proper , clean area to work on the transmission then I would have someone else service it.

If you have to change a solenoid you would have to take off the black pan in the front of the transmission. I will attach instructions to describe the job