Code P2112-Fix
I had this same code. I replaced the Anti Shutter Valve (ASV) or as the code calls it the Throttle body actuator and there was no change. The engine runs fine but I needed to clear the code to pass smog in Calif. It kept saying "stuck valve". To check it you can remove the air tube from the ASV and the butterfly valve should close for 3 sec when you shut the engine off. Finally I checked the wiring harness with an Ohm meter. To do this you follow the instructions in the Bentley service manual: remove the windshield wipers, the plastic hood cover, the firewall protector(two screws), two twist off screws that you have to cut a screwdriver slot into with a hacksaw blade, and finally you can remove the wiring harness from the ECU(Engine Control Unit). You remove the connector by pulling the side towards you straight towards you and it moves the connector off the ECU. Then you have access to the pins so you can check the resistance. Next you remove the 5 pin connector from the ASV and using the wiring diagram from the Bentley manual check the continuity pin to pin. Resistance should be near zero. In my case the final wire for the power for the motor was reading open circuit. The "Stuck Valve" code is just the valve movement indicator saying it is not moving. In my case it was a black wire with a white stripe in a twisted pair. I double checked this and then started to isolate the open in the wire. I had a fine needle to poke through the wire to isolate where the open circuit was, but before doing that, I noticed the corrugated wire cover in the front of the engine at the lowest point just behind the radiator had aftermarket tape on it indicating someone had been in there. So I opened it up and looked at the harness. At the lowest point of the harness the wire was worn through and separated. I originally obtained the car from Connecticut where I believe they sand the roads. The sand had gotten into the harness, probably wet, and flowed to the lowest point in the harness where as the harness vibrated it wore through the lowest wire of the bundle. So I spliced the wire-difficult to solder because the wire was corroded but I eventually got it-put heat shrink over it, cleaned out the sand, inspected all the wires of which some others were worn too-wrapped it all in tape, put the cover on and it was all fixed. I assume this is a fairly common occurrence with open circuits occurring at the lowest wire in the bundle in a random fashion and driving people like us nuts as strange codes happen with no apparent reason. Anyway, hope this saves someone lots of trouble.
