My friend just bought 1999 S70 Turbo AWD Automatic that is in pretty good shape except for the fact it has no reverse or neutral gears. As soon as you start it and pull it out off Park it wants to go forward and the only way to back up is to shut it off and push it backwards. The car has 191K miles and is throwing 4 codes,
P0732 Gear 2 ratio incorrect
P0740 TCC circuit malfunction
P0751 Shift solenoid A ckt performance or stuck off
P0756 Shift solenoid B ckt performance or stuck off

I ordered a Haynes manual but it is written for the UK and doesn't cover the AWD models. So far I haven't had any luck finding a Factory Service manual or much info at all on the transmission. I have heard something about electrical connections in the shift mechanism on the transmission but haven't opened that up yet.

Any ideas will be of immense help.

 

the way these transmissions work is the transmission computer takes info from the shifter, ECU, speed sensors, ABS etc and then signals the transmission's solenoid valves to effect a shift. The solenoids and valve bodies can be accessed and replaced - but from what I've seen that requires removal of the transmission from the car (about a 7 hour book labor rate just to remove/replace more if the valves need work). So you are looking at replacing the transmission unless you can find a fault in the shifter cable or PNP sensor - but the codes point to the valve body. You can also try doing a transmission flush or fill/replace but it sounds your way past the point where that would help...

As to shop manuals, I think the Haynes is a waste of money for anything more than torque specs and spark plug gaps. There's plenty online - for example browse workshop-manuals.com or google on "S70 volvo shop manual pdf" or similar and you'll probably find a scanned copy of the Haynes book and others. Finally you can go on ebay and find CDs with the complete factory books and diagnostics - search ebay for VIDA and VADIS...