I have a Toyota vitz 2007 and I am facing a problem for about 2 weeks now. Sometimes when I press the accelerator, the engine revs up but I hardly see any acceleration.

The problem is severe when I am going uphill. If I stopped midway on the slope and then tried to accelerate, the vehicle almost doesn't move. If I press the accelerator harder, the vehicle starts to jerk, but still hardly moves.

I have a problem with my wiring harness too, and I have soldered several broken wires. Mostly due to the harness, vehicle idles roughly.

I posted the this question few days back, but I wrongly mentioned that my transmission is automatic, but only today I found that it is CVT.

I took the car to a mechanic and he is going to disassemble the gear box and check tomorrow.

Would it be better to first change the wiring harness and see?

Can CVT transmission slip? Could this be a problem with the torque converter?

  • How many miles (or Kilometers) on the vehicle?
    – zipzit
    May 5, 2016 at 14:10
  • @zipzit 89000 km. I changed transmission fluid 20000 km ago.
    – Softcode
    May 5, 2016 at 14:12
  • 1
    That doesn't seem like a whole lot of mileage. I suspect either the Continuously Variable Transmission (CVT) belt is worn OR there is a hydraulic control issue such that the plates in the CVT aren't modulating correctly. This can happen if the fluid gets dirty, a control valve gets stuck or an input to the computer goes astray. Does this car set check engine light / codes? Its not a car I'm familiar with. At that mileage I wouldn't expect adverse belt wear, but its a possibility.
    – zipzit
    May 5, 2016 at 14:40
  • I realize its an old question, but how can it be you changed the fluid then some 20000km later found out its a CVT? What kind of fluid did you use?
    – agentp
    Jan 13, 2017 at 21:51

1 Answer 1


The mechanic disassembled the gearbox and there was a minor damage in a piston which controls CVT pulleys. When the piston was replaced, the problem got resolved.

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