2001 Volvo S80 T6 -Engine System Service Required

[questforbalance]

Over the past 1.5 years, I have been getting intermittent "Engine System Service Required" warning on left side of dash. I put OBD2 reader to car and no codes comes up. The warning comes on every so often, once a week or two and then goes away. I am not getting any kind of CEL on the right side of the dash, just this pesky warning. I recently found out from a Volvo mechanic how to do a quick scan by holding brake pedal down, holding in READ button and pushing rear defroster button twice to do a quick scan of systems on car. Below is what came up. Can anyone help me diagnose the problem and fix this once and for all.

DTCS in Vehicle
ABS DTC SET
SAS CHECKING
SRS READY
TCM CHECKING
ECM DTC SET
AUM READY
CEM DTC SET
DIM READY
DDM CHECKING
CCM DTC SET
PDM CHECKING
PSM CHECKING
REM DTC SET
SWM READY
UEM DTC SET

What does all this mean? What do I do next? How do I diagnose and fix the problem? I called Volvo and they told me to bring in car and for $129, they will read the car's computer. I would rather not have to pay them.



Please help me fix this once and for all. Thanks

[precopster]

Buy a Vida/Dice setup for the same price and read it yourself then post results here. Hopefully we can assist.

They may be stored code results from the indicator lever and may not reflect pending codes.