[Greenmanedlion]

The Metris steering system is “intelligent” (quotes are important) in that it automatically corrects your steering to maintain a straight line, particularly with regard to road crown; under some circumstances you can actually observe the van steer itself along certain types of gentle curves on deeply crowned roads. It is not an autonomous driving system; it’s an anti-fatigue system that works incredibly well in that function.

However, the system IS capable, under certain malfunction conditions, of attempting to steer in a direction the driver does not intend to go; it has to do with lane keeping assist, a feature the rack can accommodate but the hardware for it is not otherwise installed in the Metris. It is designed to shut down the system entirely (pawo is correct) in a fail safest manner when it is detecting what appears to be a fight between the driver and the self-correction system, without a clear reason why.

Power steering failing entirely is a superior safety condition verses the system attempting to steer heavily in a direction the driver does not want to go (which could cause the van to veer sharply off the road or even blow apart the front suspension given the 50ish degree cut angle this rack is capable of). It is obviously a poor design choice; the system should simply can the self correction system and operate manually until restart. I am not so familiar with the technical working of the rack; it is possible that simply hard shutting off The correction system is not technically possible.

 

[Greenmanedlion]

The sterness of the suspension may have something to do with it. It might be the condition of the cattle grates or the specific rumble strip might simply confuse the system to the point of convincing itself that a potential failure of the correction system may have occurred. User error is also a possibility- perhaps I should say user contribution- in either spending too long on a rumble strip or the way they react to it. It is also possible that these specific vans have some minorly defective component or sensor. It is most likely a combination of several of these frankly- or all four.

I’ve put 123k miles on mine and so far it hasn’t happened, and god willing it won’t. It is important to understand that the system of fail “safe” would be weighted to responding to any hint of the system going haywire; the potential danger of it it failing and NOT shutting off the system is massive.

If I was to take a guess, these specific rumble strips and cattle grates are very very North America specific, rare even here, and therefore not something whose dynamic with the steering system was programmed for or thought of.