Valvetronic codes
 

I’m getting the following codes, read the long post below for details. My question is has anyone had these and what was the solution?

2A69 Valvetronic actuator motor power supply
2A6A DME internal Fault
2A6B Valvetronic power limitation.


During my long process of a build I finally got to drive my car a long distance.
When I re-powered my 2008 4.8i I got all the random codes expected with power disconnection. I cleared them and did the valavetronic stops relearn. Car relearned them fine. Fast forward through my power steering snafu and I finally got the car aligned and 100% ready to put miles on.
Decided since it was a nice day I took the “long” way home from work. Drove 106 faultless miles, car had plenty of power, 0 misfires, snappy shifts and shockingly good performance for a vehicle of this vintage. Pulled in the garage feeling great looking forward to my next drive.
Start the car up the next morning to go to work and I get the half engine light and limp mode. Check the codes and figure it could be some adaptations taking place and maybe they will go away. Pulled out with my scan tool reading data and accelerated to the 55mph speed limit without issue then the power got less and less until around a mile later I could barely do 20mph with the pedal floored. During this time I had no misfires, engine still ran smooth, I heard no uncouth mechanical noises. My scan tool indicated 100% throttle position. So I don’t think it’s the well documented throttle body wiring issue.
I am leaning towards an eccentric shaft sensor or some wiring therein. Is there anyone that knows how to test it without cracking open my freshly rebuilt, leak free valve cover?

Today I got around to doing some testing. I checked every fuse with any connection to the cars computer or engine, all were good. I unplugged the valvetronic motors and tested for voltage on them. I got 0.0 on the passenger side and 0.3 on the driver side. I then tested both sets of wires with one lead on the constant power (instead of ground) to check for proper ground and both showed 14.4v to 14.8v with the car on.
I’m guessing these only have voltage at certain times. Unfortunately without an assistant I can’t read my meter(short leads that don’t stay in the plug) and start the car/cycle ignition.
So it looks like I’m going to have to get an assistant or some better leads

I checked Resistance also and got 1.3 to 1.8 ohms I’m unsure what normal is. I tested two other motors I have out of the vehicle and got similar results.

I unplugged the eccentric shaft sensors on both banks and the vehicle ran worse, noticeable shaking where it was previously smooth. I plugged everything back in and cleared all codes but the same 3 that I initially posted about can not be cleared.
The limp mode has got to the point the pedal will not let the engine rev past approximately 1500rpm.
Am I missing something? Could the DME itself be causing the problem?

probably a long shot...have you checked battery voltage while running?

Thanks for the reply, the AGM battery in it was bought 5 months ago. From my scan tool it’s over 12v with the headlights on and ignition on. But it’s always possible in these cars to have a low voltage problem.
I purchased a new valvetronic controller (computer) I’ll trickle charge the batter with it unhooked from the vehicle for 24hrs before replacing the module and releasing the valvetronic stops.

What type of charger you using? I always charge and tend the battery from the underhood points until the end-of-life stages of the battery.

I have a Schumacher MC-1 charger. Battery was bought and placed in its location but not hooked up while I replaced the engine. Was charged overnight for good measure before hooking up and starting the vehicle for the first time after engine replacement. It has been hooked up normally ever since (approx 2 months). Vehicle ran and charged properly 14.3-14.8v depending on load and has not sat for more than a week without being started and ran for at least 10 minutes. I’ve used my MC-1 on the under hood points twice while going through diagnostics to keep charged while going though scans and tests since I knew I was going to keep the ignition on for longer than 10 minutes with the engine off to diagnose a K can/ backup camera issue.

Update: issue was solved with a new valvetronic computer. I found a used one for $20 so I figured I didn’t have a lot to lose. Plugged it in (no coding needed) car fired up and runs smooth. 300mi later it’s still running great.

Good to hear.