93 saturn trans-axle codes: 11 then 45

Hi,

I need some help interpreting trouble codes/symptoms.

I have a '93 saturn SL1 with 160k miles (beater). When putting it in
reverse, there was a slam. Next the service engine light came on and
acceleration seemed sluggish with intermittent jerks (felt like when
the EGR valve got stuck open). Did the trusty old paper clip jump and
it's reading code 11, and after that the coolant temp light reads code
45. I don't know what "shift to D2" light is but there was nothing
like that flashing.

A few weeks ago the service engine light came on too, but it otherwise
felt normal and I'm used to ignoring these things by now (I get a
canister purge solenoid code every time it's taken over 55 mph), so I
had ignored it. It had otherwise been its normal rattling self since
then until now.

Any tips on what this is exactly? I'm seeing conflicting junk online
(alternator? valve body? some sensor?) so figured I'd collect some
more conflicting info. Thanks!

 

Valve body causes the slamming in reverse. Mine also slipped gears and I got
a code for no 3rd gear. New valve body fixed the problems