xaote wrote: ↑Tue Jun 07, 2022 11:20 am
Are there any other xtronic owners having occasional problems with what I'm guessing is the start stop system?
It feels like the engine is shutting down just before the car has come to a complete stop so the engine restarts again with a little burst of power. It doesn't happen every time.
I spoke to the dealership about it but they weren't aware of the problem.
Yes. Engine sometimes stops during start of braking, then restarts before coming to a complete halt, thus meaning more brake pressure has to be applied. Think the start / stop indicator shows as unavailable when the engine restarts.
Please could you detail exactly what happens for you? I have a senior manager contact on Linkedin, and the more corroborating evidence I have the better.
Exactly as you describe DaveCat (but I haven't noticed the start/stop indicator)
Just as you are rolling to a stop (about 5mph), the engine cuts out. As Calnorth says, the ecu must then recognise the error so immediately restarts the engine, I'm assuming it's the injection of fuel to restart the engine that causes the small surge of power.
To be clear, in my Xtronic, the engine does not stop and suddenly restart.
And the surge is entirely manageable by keeping your foot on the brake until fully stationary.
It could catch an inexperienced unwary driver out though
March '22 - J12 1.3DIG-T 160 CVT Tekna+ with all wheel drive - Pearl Black
July '19 - J11B 1.3DIG-T 160 DCT Tekna - Vivid Blue
March '17 - Qashqai J11A 1.5dci n-connecta - gunmetal
September '14 - Juke 1.5dci gunmetal ascenta premium (red accent packs)
calnorth wrote: ↑Wed Jun 08, 2022 7:53 am
One thing is definite ref Stop/Start...the engine "must not be stopped" (or started) when the vehicle is rolling. A sensor specifically monitors speed.
Is that confirmed for the J12 since I presume your experience is only on the J11B?
One of the things that surprised me when I switched to the Ignis is that Stop/Start actuates before you come to a complete halt - might be the same on the J12?
I can't confirm J12 anything. But I can't imagine much down in the long grass has changed.
Auto box variants are somewhat different (sensors/ECU software) in that an engine cut could be executed on vehicle rolling at very low speed. Perhaps a rev up on Re Start is acceptable? Compare Rev counter swing on Manual Start and Restart.....if you can
The business of a surprise Re Start on braking could be that ABS system (Vacuum) has depleted too much. Vacuum is also monitored as a condition of Stop/Start ready or active. Plus other sensors of course.
The J11 Auto box users might advise?
Last edited by calnorth on Wed Jun 08, 2022 9:53 am, edited 1 time in total.
QaiFan wrote: ↑Wed Jun 08, 2022 8:48 am
I guess this only occurs in the xtronic versions, since I can not recall this early engine cut-off happening with my J12 MT6 !?
I don't think you would have noticed it because it is happening at a speed where you would have already depressed the clutch to avoid an engine stall Qaifan.
MikeGC wrote: ↑Wed Jun 08, 2022 9:34 am
To be clear, in my Xtronic, the engine does not stop and suddenly restart.
And the surge is entirely manageable by keeping your foot on the brake until fully stationary.
It could catch an inexperienced unwary driver out though
Yes, everytime it has happened to me I am already covering the brake anyway but it could catch someone out.
If it's not the start/stop, what do you think is causing the surge Mike?
calnorth wrote: ↑Wed Jun 08, 2022 7:53 am
One thing is definite ref Stop/Start...the engine "must not be stopped" (or started) when the vehicle is rolling. A sensor specifically monitors speed.
Is that confirmed for the J12 since I presume your experience is only on the J11B?
One of the things that surprised me when I switched to the Ignis is that Stop/Start actuates before you come to a complete halt - might be the same on the J12?
Yep - this is the coasting start/stop feature as i understand it - well on he Xtronic model.
"When decelerating, energy is recovered through regeneration and stored in the Lithium-ion battery. This charged energy is then supplied during Idling Stop, Coasting Stop (Xtronic versions only) and Torque Assist.
When coasting to a stop, at speeds of less than 18kph, and `brake on', the engine will switch off and the stored energy is used to power the vehicle's electrical equipment. This allows engine stop to be extended and fuel consumption lowered as a result."
MikeGC wrote: ↑Wed Jun 08, 2022 9:34 am
To be clear, in my Xtronic, the engine does not stop and suddenly restart.
And the surge is entirely manageable by keeping your foot on the brake until fully stationary.
It could catch an inexperienced unwary driver out though
Yes, everytime it has happened to me I am already covering the brake anyway but it could catch someone out.
If it's not the start/stop, what do you think is causing the surge Mike?
.
I think it is the stop/start system
It doesn’t happen when I have stop/start turned off - same in the J11B DCT auto I had
March '22 - J12 1.3DIG-T 160 CVT Tekna+ with all wheel drive - Pearl Black
July '19 - J11B 1.3DIG-T 160 DCT Tekna - Vivid Blue
March '17 - Qashqai J11A 1.5dci n-connecta - gunmetal
September '14 - Juke 1.5dci gunmetal ascenta premium (red accent packs)
MikeGC wrote: ↑Wed Jun 08, 2022 9:34 am
To be clear, in my Xtronic, the engine does not stop and suddenly restart.
And the surge is entirely manageable by keeping your foot on the brake until fully stationary.
It could catch an inexperienced unwary driver out though
Yes, everytime it has happened to me I am already covering the brake anyway but it could catch someone out.
If it's not the start/stop, what do you think is causing the surge Mike?
.
I think it is the stop/start system
It doesn’t happen when I have stop/start turned off - same in the J11B DCT auto I had