Sudden total loss of power while driving, 2008 Toyota Sienna

While driving on the freeway, near the end of a 90 minute trip, the van (2008 Toyota Sienna) loses power. Tach remains around 2k but no power gets to the wheels and I am, in effect, coasting. Power steering drops out. Then the engine stalls. No check engine light then or now but the light is working.

After a few tries, the engine restarts. I make for home, the same thing happens again. Again, I get it restarted and I am able to make it home.

That was last night and the van is currently parked.

What happened? How can I fix it?

When you press on the gas pedal during there is no forward motion does the engine rev up or does it remain at 2000 RPM? If it revs you may have a transmission problem. I’d check the fluid first since low fluid or degraded fluid is a cheap fix if it works.

No, there was no RPM spike when pressing the gas pedal. I did check the transmission fluid just now, the level look good and the fluid is not “dirty” or gritty.

You did have the engine running at normal operating temp on level ground when you checked it right??

How did it drive once you got it started again before it died again???

Level ground but, no, it wasn’t running. Didn’t know that. Will check again.

What you describe is a symptom of a bad crank sensor.

But the tach was still displaying 2000 RPM’s when there was no throttle response.




How did it drive once you got it started again before it died again???

I was a bit rattled but it seemed normal.

I agree with Tester on the crank sensor, they can get hot and crack open and stop working but when they cool down the work again, but normally not for much longer…

You can take a chance and replace it or get a scanner that can read if you are getting a crank signal when not running…

Now does it just stop running, or does it slowly loose power like it is bogging down?

Now does it just stop running, or does it slowly loose power like it is bogging down?

Both times it happened things moved fairly quickly, first power was lost (tack stayed around 2k with no spike for more gas). Within a few seconds (more than three but less than ten) the power steering would go out and the engine would stall. So it seems fast to me but it wasn’t like “finger snap” fast.

Yes an automatic transmission/transaxle has to be running and operating temp in order to get the proper fluid level…

Yeah, doing it correctly showed it is low and dirtier than it looked on first glance. I don’t know if that is because having it on stirred up stuff or what. It’s bad enough that I feel it should be flushed rather than just adding more. I have never done a flush/drain.

How many miles are on it???

It’s at about 209K

If that fluid has not been changed then just top it off, you will never hurt it topping it off but you can KILL it changing or flushing it when it has not been properly maintained or burnt… I would advise to take it to a dealer or transmission shop to be evaluated and safe to flush and or change…

I can get into way more detail if you want… lol

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It would be very unusual for the transmission to cause an engine to stall.

The tachometer signal is based on the crankshaft position sensor signal, seems that the CKP sensor is working. When the engine loses power, it continues to rotate due to the wheels/transmission rotating.

You need to analyze the system while driving using a diagnostic scan tool and fuel pressure gauge.


I looked at some info (2008 Toyota Sienna Transmission Fluid Change - YouTube) and I don’t think I want to try a flush myself. I’ll add more for now.

While adding transmission is needed, I’m not sure that’s the source of my experience last night. The crankshaft sensor, is there a way to check that? I don’t have a check engine light so I don’t think a code reader would show anything but I may be wrong there.

Read it again.

Check Engine Light

A failing or failed crankshaft position sensor may cause the check engine light on your dashboard to come on. A diagnostic scan tool will show a code between P0335 and P0338**. The check engine light doesn’t always come on, though, so you could be experiencing any of the above symptoms for some time before you see the warning light.**


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Yes the scanner can/will show pending codes as well as history codes even if light is not on…

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Many possible culprits, good ideas above. I think if I had that problem first test I’d do is make sure the electrical system supply voltage is good (12.5 - 14.5 volts) when symptom first occurs.