Nissan QashQai Forums

Hello.

I was just wondering if anyone know why my Qashqai -16 1.2L petrol is behaving like this? Mostly when on Cruise control. Its an automatic. 50 000km on the clock. (31000 Miles)



I took it to the Nissan dealer and they said that they couldn’f find anything thru the OBD2-port.
When its dropping ~200 rpm the entire car shakes.
If I manually put the 7th gear in, it doesn’t drop.
Sorry for the bad english.

Best regards.

Welcome to this forum.

Let's hope someone will be around soon with CVT experience.

That is how they work, in a CVT box you only really have one gear and the cones operate to make that gear higher or lower ratio. When you engage cruise control, the engine is trying to run as efficiently as possible and any slight deviations in the road surface will raise and lower you rpm. It becomes more noticeable AFAIK on lower BHP cars as the engine needs to work a little harder to maintain the speed, which is what the cruise control is trying to do.

Qashowner wrote: ↑Sun Dec 06, 2020 4:47 pm That is how they work, in a CVT box you only really have one gear and the cones operate to make that gear higher or lower ratio. When you engage cruise control, the engine is trying to run as efficiently as possible and any slight deviations in the road surface will raise and lower you rpm. It becomes more noticeable AFAIK on lower BHP cars as the engine needs to work a little harder to maintain the speed, which is what the cruise control is trying to do.

Thanks for the reply but I don’t think this is normal since the RPM drops 200 rpm, and then jerks, and goes up to 2200(or whatever it was at before the drop)

If I drive 25 km, grab a meal (I mean wait 15-30 min) it runsten perfect. The jerking started 3 months ago, maybe 1 time during 10 drives. Now it does it 98 out of 100.

Since I’ve got 2 kids, and winter is coming up here in Sweden (-25C) I don’t want the car to break down. I consider leaving it to the local dealer, but it’s 70km from my town, and I dont feel to pay lots of money for them to guess what it is.

My guesses is at the Air flow meter, or something like that.

If the dealer missed that erratic performance then there is something wrong with the dealer. The diagnostics for engine control as regards cruise control or as Nissan call it AUTOMATIC SPEED CONTROL DEVICE (ASCD) is large. It requires Nissans Consult test and diagnostics tool to determine what the fault is.

We do not have accurate technical details of engines or gear boxes (CVT) to determine the problem.

ASCD uses various sensors to signal the ECU to control fuel and timing etc. The rev fluctuation/juddering could be symptomatic of the ECU or its actuators failing to fuel the engine...a kind of stalling. You also seem to experience a temperature dependency which could be significant?

You need to speak to a dealer technician who understands this problem...not a booking in clerk. Sorry to be unhelpful.

calnorth wrote: ↑Mon Dec 07, 2020 9:16 am If the dealer missed that erratic performance then there is something wrong with the dealer. The diagnostics for engine control as regards cruise control or as Nissan call it AUTOMATIC SPEED CONTROL DEVICE (ASCD) is large. It requires Nissans Consult test and diagnostics tool to determine what the fault is.

We do not have accurate technical details of engines or gear boxes (CVT) to determine the problem.

ASCD uses various sensors to signal the ECU to control fuel and timing etc. The rev fluctuation/juddering could be symptomatic of the ECU or its actuators failing to fuel the engine...a kind of stalling. You also seem to experience a temperature dependency which could be significant?

You need to speak to a dealer technician who understands this problem...not a booking in clerk. Sorry to be unhelpful.

Thank you for your reply. I was mostly scared that it would be the gearbox that’s breaking down. I’ll give the local dealer a ring, and book a full check of my car. Hopefully if it’s a major error my Nissan insursance company Will help, or maybe goodwill from the garage. Thanks again.

ok..we are guessing really and due to lack of technical info. So let us know what happens please

I took my car to the dealer today. They suspected the gearbox slipping. They were gonna make a call to Nissan, for trying to get fixed on extended warranty. If that didn’t work they were going to try on my insursance.

kladdis wrote: ↑Mon Jan 11, 2021 7:29 pm I took my car to the dealer today. They suspected the gearbox slipping. They were gonna make a call to Nissan, for trying to get fixed on extended warranty. If that didn’t work they were going to try on my insursance.

Hi kladdis,

How did this work out for you? Have the same car (Qashqai 2016 1,2 petrol) and experience the exact same behavior. My problems started when the car was 1,5 year, around 8-9.000 km. And is still going strong, now passed 65.000 km. I`ve had the car in with the dealer 10 (!) times, and now after three years and warranty just expired I get that "this is normal behavor". According to a Nissan bulletin (or what they called it) it`s expected that "the RPM will oscillate +- 300-500 RPM during downhill detection or high speed curves". I'm baffled by learning this just after warranty expiration. I am wondering if this at all can be solved in any way, or is it the fact that it will always be like this. The bumping feeling in the car when it occurs makes the kids in the backseat go "oh, this was a bumpy road...". I might add that gearbox was replaced, some valves and sensors also replaced and some other minor stuff, all of which had no effect.

This problem appears to be a signature of some of these CVT boxes. The decisions to be made about engine power and gear selection is decided within the Traction Control Module (TCM). Or Transmission Control Module. Either way it seems to be a point/area of indeterminacy in which the engine and gearbox loose correct control. Engine control comes from the Engine Management system. There are other sensors. (oil temp, gear selection and input output speeds various)

Such behaviour could be termed a "race" where the engine inputs power and the TCM lags or leads in applying it to the gearbox. Its either a race up or down the gear engagement. Hence the jolt(s).

I suspect Nissan have applied all the software updates that they deem fit and thats it? The problem is left with the Customer mainly. And dealer(s) that don't have a hope in hell. Sorry.....