My 08 h3 for the past three days has shut down while driving into reduced power mode with the dash saying stability system failed and reduced power. The car jerks in this mode till I shut the engine off. I got the codes u1017 (ecm), c0240 (tcm), p0336 (crankshaft sensor) and p0651 (sensor b). I have read many post on here and many have talked about a new computer. Is that what this looks like or could it just be a crankshaft sensor? I also just had the throttle body replaced two months ago. Any input or anyone gone through this with results would be appreciated.

 

Welcome to HF.

There are many reasons that can cause what you are describing and it is possible you have more than one thing going on at the same time, so let's start with the easy stuff.

Does the H3 have a sunroof? If so, has the passenger side floor ever been wet?

Does the H3 still have the crappy azzed OEM factory Battery Terminal Connectors? If so, they are a known culprit of electrical Gremlins and should be the first mod done to every H3/H3T as they will all fail. Not a matter of if, just when. The PCM, TCM and BCM are all sensitive to minute changes in voltage caused by a poor connection to a fully charged battery.

Replace the OEM terminal connectors with a quality aftermarket set, like Stingers or your favorite brand.

 

Since you mentioned the sunroof, which I have , I came outside and lifted my floor mat and there is a wet spot right in the middle of the floor. What should be the next step. I am guessing clean the drains and lift the carpet? Thanks.

 

More than clean the drains, you need to fix them. See: Finally, a fix for clogged sunroof drain tubes

You can also Google it, there are some pretty good vids.

You need to dry it out thoroughly, lifting the carpet would help avoid mold etc....

When a sunroof leaks, water runs down the A pillar passenger side, and behind the kick plate where the BCM and Transfer Case Control Module (TCCM) are located, both do NOT like water. If the TCCM has a short or voltage fluctuations not anticipated by the PCM, it can trigger reduced power and StabiliTrack issues. Think of it like a cell phone, once wet it may work again if you dry it out and do not try to turn it on before it is dry, then again, might have issues, or need to replace it.

Probably not related to any crankshaft sensor fritz.... but the battery terminal connectors could be?

What was the problem leading to the Throttle Body replacement?

 

I fixed the drain today using directions and YouTube. Though it is incredibly difficult to get the grommet all the way back in the hole on the fire wall. Lifted the carpet but it is pretty soaked. Car is still doing the same so it's going into the shop tomorrow and hopefully this leak issue helps pinpoint them to the correct fix, maybe a short or tccm. I had the throttle body replaced because the car was just shutting down on me driving, bad gas mileage and running hard. No warning, just shut down.

 

Alright, got it solved. Thankfully the water did no damage, other than carpets of course. I had a wire that had a hole rubbed through down by the crankshaft. It was grounding out. I got the wire wrapped all insulated and I'm back on the road.

 

I have learned that if strange things start happening,
look at the battery 1st. Just my 2 cents worth.