trifecta engine failsafe, no idea why

[sandbagger]

A bit stumped, thought it was the ICV, but nope.
2004 3.0
starts and idles fine, drives down the road a bit fine, then will set the trifecta lights up trans failsafe and engine failsafe
check codes and I get :
D3 Idle speed Control Valve mechanical fault
55C4 No message from DSC
5F1D DSC Engine management interface
91 EGS CAN torque reduction
Once the codes are set, it wont idle and codes dont really seam to set unless I am in lift and coast.
now if I clear ICV code, it will drive fine until I coast a bit.
ICV valve has been replaced so that is ruled out
anyone have any ideas as it seems to be several generic codes

[80stech]

You shouldn't rule out the idle valve just because it has been replaced. Usually the most important code is listed first. Do all the codes come back everey time under same conditions? The first thing to check is all the simple stuff, battery, charging, connections and ground wires.

[sandbagger]

clear codes and they all come back at once.
ICV orig was not stuck, tried cleaning it and then ordered a new one, same thing
Battery Voltage is fine grounds are good....
now I am seeing that the 5F1D might be a wheel sensor?

[80stech]

With what tool are you reading the codes?

[sandbagger]

not wheel sensors, they are all reading the same

Foxwell NT644 Pro.... have had good luck with most things with it
I will pull the laptop out on monday have to let it charge

[sandbagger]

plugged the laptop in and got nothing new, same codes

I am now completely at a loss is its not pointing me to anything directly

anyone have any bright ideas

[X5chemist]

My start would be 55C4. No message from DSC. A wheel speed sensor is acting up intermediately. Or steering angle sensor? The last two probably relate to 55C4.

As for D3, I would suspect the MAF sensor. Clear the codes and run without the MAF connected. How long does it take for a code set? Drive it reasonably to the same amount of time.

[80stech]

Some more detailed history might help. I still wouldn't ignore the Idle valve code. The next codes point to a bus communication problem.

[sandbagger]

I did look at live data on the wheel speed sensors, never saw anything strange
SAS was replaced 2yrs ago, I did look at the live data, didnt see anything with it either.
ICV, like I said, I cleaned the original(not stuck) and replaced with a new valve also and same problem

why would a D3 code point toward a mass air meter? its saying its a ICV fault

[80stech]

Anything like the throttle valve, gas peddle position, vacuum leak (would probably set a mixture code) or even(less likely) MAF sensor not working correctly could in theory fool the DME into thinking the ICV is sticking.
Is there a wheel sensor code ?? You could easily have a bad wheel sensor that you can't see a problem with in the live data.
I would check the wiring and voltages at the ICV.