You may experience just a check engine light, but you may also have an engine that will not start (won't turn over) and erratic transmission shifting. A diagnostic check will turn up a 3-1-3 code in the transmission control module for the gear position sensor. Replacement of the sensor will be necessary to address this issue.Google+
Car Problem Reports
Volvo 850 Engine will not start, will not crank over, check engine light on
Volvo 850 Problem
Visitor, 1993 Volvo 850, 93,000 mi
Most times Im not able to drive in Drive and I have to drive in gear 3 unless I've been driving for a while. I just replaced the starter and now my check engine light is on. In the morning my car doesn't warm up like it used to and it feels as if it's pulling. It kinda sounds like a race car, the lid "vrooomm" sound. Once I turn off the ignition, the car will not turn over, but the lights do come on.