I have a 2001 Chevy 3500 4x4 duramax diesel 6.6, and a Allison tranny. The tranny will not engage into forward andreverse. Has a p1711 code (pressure switch E stuck closed) what is the problem causing this?

everyone seems to think that it's a PNP switch gone bad~

Already tried that.....

...okay power to the switch? continuity of the connection?~

if it is a PNP switch voltages would be delicate....wires would be tiny~ and difficult to test~...because it's one half of a transistor...that the ECU loves, but the material world has problems with~

Both of those are good

it's more of a misappropriation of the technology issue....I can remember in 1973 when MOPAR was so concerned about people stealin' their solid-state ignition design, that they encapsulated the whole affair in a Dow-chemical Potting material....humph try takin' that then~

...but fragility with delicate sensors continues to plague automakers...man, they just don't get it...YES...an uneducated GORILLA is going to be drivin' down the highway (kept ridin' my tail all the way) and will not even pay much attention to what MAKES it work, rather than "it ain't workin'!!" why not...the mechanic musta done somethin'~

Chevy Impala ABS is a PRIME example....the delicate wires that barely measure a pulse are routed THRU the frame TO the sensor in the wheel....circus of magnets as I recall~....anyways these things FAIL Bre McGrogan (a model and beautiful person) had this problem and I was not able to help...if it weren't for GURU John Saffran this would have remained a mystery (to me at least)~...but the delicates....don't wash the delicates with the leather garments~!

so the fragile wires I'd suspect first...because road debris comes launching up at 70 Mph, depending on the mass of the object can tear wires easy~