Gasoline engine turns on unexpectedly

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kmarko

New member
Joined
Mar 30, 2024
Messages
2
Location
Hungary
This morning (in realitvely warm, ~20 celsius degrees weather) - after years of reliable drive - my car (Audi a3 etron 2017) started to act weird. At full electric charge and in EV mode, after a short distance travel (100-200m) and a low acceleration the gasoline motor turned on immediately, changed to "battery hold" drive mode, and in the middle panel there was a warning: Drive: Engine required (translated from the original language, hungarian: "Hajtás: Motorműködés szükséges").
After a while (approx 1-2 km-s) the EV mode was available again and I could drive in EV mode ~30 km-s (without gasoline engine).
During the day i recharged the battery.
Afternoon i had a 2 km-s trip, andit all happened again.
Why is it happening? Is it a battery cell issue? What should i do?
 
Last edited:
Hi @kmarko ! I am not 100% sure, but this is a common "issue" that PHEV owners report to the dealerships. They complain that the car although full of electricity, used the engine, why?

A motor has a minimum runtime requirements. every X amount of miles, the engine needs to run Y amount to remain healthy. You probably don't want 1 year old gas in your tank. So in the case where you are a local driver and always drive it in EV, the car has no choice but to force the engine on from time to time.

Folks who drive a healthy mix of EV/ICE will never run into this behavior, which should not be considered a problem.

Can you confirm how often you drive in EV mode vs using the gas engine? Do you remain in a small circle most of the time and drive mostly in full EV mode?
 
I agree with SirCharges. You want to get the gas engine lubricated (all internal engine parts) periodically. Otherwise, you may have problems later.
I use EV mode most of the time so once a week I will put the car in Sport Mode which holds the EV and turns on the engine. I'll drive for about 10 minutes then switch back the EV mode. About once a month I'll take the car on the highway in Sport Mode to let the gas engine reach operating temperature.
 
Hi @kmarko ! I am not 100% sure, but this is a common "issue" that PHEV owners report to the dealerships. They complain that the car although full of electricity, used the engine, why?

A motor has a minimum runtime requirements. every X amount of miles, the engine needs to run Y amount to remain healthy. You probably don't want 1 year old gas in your tank. So in the case where you are a local driver and always drive it in EV, the car has no choice but to force the engine on from time to time.

Folks who drive a healthy mix of EV/ICE will never run into this behavior, which should not be considered a problem.

Can you confirm how often you drive in EV mode vs using the gas engine? Do you remain in a small circle most of the time and drive mostly in full EV mode?
We have NEVER choosen battery save or HEV mode (not since 2020 when we last towed our small trailer) in our 2017 Audi A3 Sportback e-tron, but we have had the car switch to battery hold and start the gasoline engine every 3 months or so. We only drive 2K miles annually now, since our battery pack has significantly declined in range, though Audi USA says nothing is wrong (at 22K miles on the odometer) with our battery pack after TACS testing. We are below 70% of original range, occasionally dropping to 40-50%, on days warmer than 55F. We have not refueled our gasoline tank in nearly 2 years now, driving 99%+ electric, switching to our Tesla Model 3 for longer trips. The California 10 year 150K mile PHEV battery pack warranty is being ignored by Audi USA. We are now planning to ask the California Attorney General to force Audi to enforce the Law!

Our Audi dealership claims that there is nothing in all their info stating that our Audi should bypass our drive selection and turn off EV only mode. There is no need to run the gasoline engine, unless the fuel system integrity is compromised. It is not necessary to run the engine for lubrication if it is not being operated. That is old technology rules, not high quality PHEV rules.
 
Is this a statement that you are making or that the dealership told you about?
This is MY statement, based on research of PHEVs from many manufacturers. Audi also uses very high quality synthetic oil and oil filters, which are guaranteed to last well beyond 12K miles, even up to 20K miles, though that is NOT guaranteed or recommended. Considering a PHEV where the engine has run for only 5-10 miles in the past 2 years, the engine does not require constant lubrication for an ICE that is not used much at all.
 
This is MY statement, based on research of PHEVs from many manufacturers. Audi also uses very high quality synthetic oil and oil filters, which are guaranteed to last well beyond 12K miles, even up to 20K miles, though that is NOT guaranteed or recommended. Considering a PHEV where the engine has run for only 5-10 miles in the past 2 years, the engine does not require constant lubrication for an ICE that is not used much at all.
Fair enough. I don't think the need to run the engine is only because of the engine oil, but I'm not a mechanic so I cannot argue this, but I'll stand firm on my statement about PHEV vehicles having the functionality I mentioned baked into them, at least some of them. We can believe they don't need them and we might be right, but some of them have it and I'm putting my money on our A3s being setup in this manner as well.

A close friend also got his first PHEV, Jeep 4xe and many jeep owners online were complaining about the engine going on randomly, majority of folks who reported this also confirmed they run the car almost always in EV mode because they have a super small commute of drive radius. The dealers also kept telling them they were crazy and that there is nothing wrong with their cars.

I believe PHEVs are very complex machines and most folks myself included cannot possibly understand why it does all the things it does. Especially when even the customer facing end of Audi employees aren't trained on this level of detail. It is however super fun to get to know a new car, especially one that has 2 different sources of fuel.

All these PHEVs will default to EV only mode, so if you live and work and shop within a 10 mile radius, you will likely always be in EV only mode, then your car will run the engine here and there for you. We can argue about if it should do it or not, but I do believe modern day PHEVs are programmed to have a max amount of "no run" time for the ice components. I can't say everything above with 100% certainty, but I'm just putting down what I've gathered in case it's helpful for anyone else.
 
The engine starting up uncommanded is mentioned either in the owner's manual or one of the service training guides. I will try to find it if I have time.
 
Yeah - I asked a couple of friends who are techs at VW (the GTE is basically an Audi A3 in VW clothing), and they said it does that by design. Every time the engine does kick in, well.....that drive to the grocery store just turned into a little romp on the highway to get everything good and hot.
 
Yeah - I asked a couple of friends who are techs at VW (the GTE is basically an Audi A3 in VW clothing), and they said it does that by design. Every time the engine does kick in, well.....that drive to the grocery store just turned into a little romp on the highway to get everything good and hot.
Thanks for sharing your experience and info here. Appreciated.
 
Yeah - I asked a couple of friends who are techs at VW (the GTE is basically an Audi A3 in VW clothing), and they said it does that by design. Every time the engine does kick in, well.....that drive to the grocery store just turned into a little romp on the highway to get everything good and hot.
I have read the entire manual and spoken extensively with our local Audi service personnel. If our Audi PHEV is set to ALWAYS start and operate in EV only mode, that is what it is supposed to do. Audi’s PHEV system is NOT like Toyota’s where the gasoline engine comes on often during nearly every drive. EV only mode is exactly what it is called. No ICE operation is supposed to occur. Our A3 Sportback e-tron turns on the ICE engine, switching to “battery hold” mode, only every 4-8 months, for absolutely no reason. We paid for a major service investigation at Audi to determine why it was occurring anyway. They are unsure why, but I believe it is faulty hardware or software, just like the issues with attempting to start, with the brake fully depressed, but the Ready words fail to appear, requiring a shutdown and restart. And also like the installation of cheap and dated 3G tech that ended our Audi Connect app connection to our car YEARS ago. Yes, Audi 4 & 5 series vehicles were updated with 4G, but not our $52K A3 Sportback e-tron, which cost more than most of those 4 & 5 series cars.

We are discouraged and upset with Audi USA refusing to help owners, instead telling us to “then buy a new Audi”. Yes, that IS a quote. Our dealer, at least, is not like Audi USA.
 
Our A3 Sportback e-tron turns on the ICE engine, switching to “battery hold” mode, only every 4-8 months, for absolutely no reason.

@dlinkA3 this is EXACTLY the behavior I'm describing. But it sounds like you already know everything about the e-tron and you aren't here for help, just to vent your frustrations. I'll hold off on providing further opinions and knowledge to you sir.
 
I spoke to an Audi rep several months ago and told him that I suspect that there are very few, if any, software developers assigned to work on the A3 e-tron software. He didn't disagree. In any case, my car has begun to intermittently switch to battery hold mode (after 5+ years of never having done that). I presume it to be related to battery degradation. It's only happened when the motor is under some kind of load, such as accelerating up a hill. My guess is that the software detects that there is not enough electric power needed at the moment.
 
I spoke to an Audi rep several months ago and told him that I suspect that there are very few, if any, software developers assigned to work on the A3 e-tron software. He didn't disagree. In any case, my car has begun to intermittently switch to battery hold mode (after 5+ years of never having done that). I presume it to be related to battery degradation. It's only happened when the motor is under some kind of load, such as accelerating up a hill. My guess is that the software detects that there is not enough electric power needed at the moment.

Oh that's very interesting, so for you, you've been able to correlate the engine coming on to needing more power? We could very well be dealing with multiple different root causes here with a similar symptom.

Let's try to put in as much detail as we can, I think it's very important for us to think of our driving habits, did yours change at any point? Did you change a job and go from a battery+gas commute to a battery only one?

How often does it happen? Daily? Weekly? Monthly? Yearly?

Edit: I forgot to mention that I completely agree that Audi has abandoned this vehicle. It is my understanding that across 3 model years Audi only sold ~5,000 units of the A3 e-tron in the USA. It's pretty clear they aren't going to invest any time on taking care of such a nitch group. I'm sure you know the fact that since 3G was deprecated they made zero effort to work around it using MMI Wifi/BT to communicate somehow at short range, but nah.

I don't wanna make excuses for them, but I'm noticing more and more that all products in the market of today, gets left in the dark much quicker than they used to. I don't like it, we are moving too fast, but that's probably because I'm getting old.
 
Our gasoline engine has come on for absolutely no reason at all. We only drive our A3 Sportback e-tron in town and it is all FLAT, without any hills. We also only drive it on city streets at a maximum of 45mph, so it has not been requiring extra power at all. I understand that the engine can start when under extreme acceleration, but we have NEVER done that in our Audi (our Tesla Model 3, yes, but only at EV demonstration events or for family).
 
The A3 etron is IMO very much a "compliance" vehicle... If you study the amount of things put into making the entire package work you'd have a hard time believing that this car would make the company any money. It existed to meet fleet mpg goals. None of the components are shared with any other models in their line up, even the 1.4T is a special edition. You can compare this car with a plain jane A4 that sells for about the same price but is powered by nothing more than a 2.0T and a 12V battery for electrics. Perhaps half the complexity.

Having said all that not all the work done has been in vain, you have PHEV versions of the Q5, A6, A7 and A8. You can see a lot of the work done on the A3 get reused in those models... Sure, some of the bits are different, the ICE, the gearbox, HV battery etc but I think they all have the same foundation that was laid down by the A3... Thus I don't think I agree that this is a totally neglected model.

The reason why they won't sell the A3 PHEV anymore in N America is because they have the EVs now to meet fuel economy fleet averages... the A3 was brought in in 2016 after the diesel scandal... The diesels were the original plan for meeting CAFE standards. The A3 PHEV does not make sense financially to the company, it was sold to avoid big fines.
 
From the manual:
"Conditions for electric driving
The EV mode can only be switched on if the following
conditions are met:
- The charge level of the high-voltage battery
must be sufficient.
- The temperature of the high-voltage battery
must be adequate (outside temperatures not
below approximately 14°F / -10°C and not
above 104°F / 40°C).
- The speed must not be higher than approximately 80 mph (130 km/h).
- Kick-down must not be activated.
- The sport drive mode "S" must not be selected.

EV mode is switched off if one or more of the
conditions are not met. The gasoline engine will
start automatically. The [engine on] indicator light turns
on as a message in the instrument cluster. The
LED in the [EV] button and the [EV] indicator light
turn off.
Electric drive mode will not continue automati -
cally. Reactivate the EV mode.

(Information) Tips
It may be necessary for the gasoline engine to run longer
for technical reasons, such as when condensation accumulates
in the engine. Driving exclusively in electric mode
is not possible in this phase."

We have also very occasionally encountered the ICE turning on
without these conditions, however this is for relatively brief periods
and the dealer insists that it is for the health of the ICE - the
vehicle senses that the ICE needs to run.
The dealer states that the warranty would be voided
if the ICE is not run regularly (eg. as stated by bruuster above).
Of course, this is the same dealer that told me the reason
the 12V battery failed was because I wasn't using the
ICE, which was false - there are other threads on this topic.
We do use a gasoline stabilizer, given our low total gasoline
consumption (less than 4 fills / year).
 
From the manual:
"Conditions for electric driving
The EV mode can only be switched on if the following
conditions are met:
- The charge level of the high-voltage battery
must be sufficient.
- The temperature of the high-voltage battery
must be adequate (outside temperatures not
below approximately 14°F / -10°C and not
above 104°F / 40°C).
- The speed must not be higher than approximately 80 mph (130 km/h).
- Kick-down must not be activated.
- The sport drive mode "S" must not be selected.

EV mode is switched off if one or more of the
conditions are not met. The gasoline engine will
start automatically. The [engine on] indicator light turns
on as a message in the instrument cluster. The
LED in the [EV] button and the [EV] indicator light
turn off.
Electric drive mode will not continue automati -
cally. Reactivate the EV mode.

(Information) Tips
It may be necessary for the gasoline engine to run longer
for technical reasons, such as when condensation accumulates
in the engine. Driving exclusively in electric mode
is not possible in this phase."

We have also very occasionally encountered the ICE turning on
without these conditions, however this is for relatively brief periods
and the dealer insists that it is for the health of the ICE - the
vehicle senses that the ICE needs to run.
The dealer states that the warranty would be voided
if the ICE is not run regularly (eg. as stated by bruuster above).
Of course, this is the same dealer that told me the reason
the 12V battery failed was because I wasn't using the
ICE, which was false - there are other threads on this topic.
We do use a gasoline stabilizer, given our low total gasoline
consumption (less than 4 fills / year).
I didn't think of temperature as a wrinkle in the game. We should all consider that factor also when we think the engine should not have turned on.

Thanks for sharing this information with us. Condensation buildup is a very interesting variable also. Sounds like there are many reasons why the same thing could happen, some of which are valid normal reasons, some of which can be a sign of a failre elsewhere.

Very complicated situation to try and prove, perhaps there is a log that can show low battery voltage supply if the owner is suspecting that's why ICE goes on...
 
From the manual:
"Conditions for electric driving
The EV mode can only be switched on if the following
conditions are met:
- The charge level of the high-voltage battery
must be sufficient.
- The temperature of the high-voltage battery
must be adequate (outside temperatures not
below approximately 14°F / -10°C and not
above 104°F / 40°C).
- The speed must not be higher than approximately 80 mph (130 km/h).
- Kick-down must not be activated.
- The sport drive mode "S" must not be selected.

EV mode is switched off if one or more of the
conditions are not met. The gasoline engine will
start automatically. The [engine on] indicator light turns
on as a message in the instrument cluster. The
LED in the [EV] button and the [EV] indicator light
turn off.
Electric drive mode will not continue automati -
cally. Reactivate the EV mode.

(Information) Tips
It may be necessary for the gasoline engine to run longer
for technical reasons, such as when condensation accumulates
in the engine. Driving exclusively in electric mode
is not possible in this phase."

We have also very occasionally encountered the ICE turning on
without these conditions, however this is for relatively brief periods
and the dealer insists that it is for the health of the ICE - the
vehicle senses that the ICE needs to run.
The dealer states that the warranty would be voided
if the ICE is not run regularly (eg. as stated by bruuster above).
Of course, this is the same dealer that told me the reason
the 12V battery failed was because I wasn't using the
ICE, which was false - there are other threads on this topic.
We do use a gasoline stabilizer, given our low total gasoline
consumption (less than 4 fills / year).

From the manual:
"Conditions for electric driving
The EV mode can only be switched on if the following
conditions are met:
- The charge level of the high-voltage battery
must be sufficient.
- The temperature of the high-voltage battery
must be adequate (outside temperatures not
below approximately 14°F / -10°C and not
above 104°F / 40°C).
- The speed must not be higher than approximately 80 mph (130 km/h).
- Kick-down must not be activated.
- The sport drive mode "S" must not be selected.

EV mode is switched off if one or more of the
conditions are not met. The gasoline engine will
start automatically. The [engine on] indicator light turns
on as a message in the instrument cluster. The
LED in the [EV] button and the [EV] indicator light
turn off.
Electric drive mode will not continue automati -
cally. Reactivate the EV mode.

(Information) Tips
It may be necessary for the gasoline engine to run longer
for technical reasons, such as when condensation accumulates
in the engine. Driving exclusively in electric mode
is not possible in this phase."

We have also very occasionally encountered the ICE turning on
without these conditions, however this is for relatively brief periods
and the dealer insists that it is for the health of the ICE - the
vehicle senses that the ICE needs to run.
The dealer states that the warranty would be voided
if the ICE is not run regularly (eg. as stated by bruuster above).
Of course, this is the same dealer that told me the reason
the 12V battery failed was because I wasn't using the
ICE, which was false - there are other threads on this topic.
We do use a gasoline stabilizer, given our low total gasoline
consumption (less than 4 fills / year).
We meet ALL the conditions mentioned in the manual, yet the ICE still comes on, refusing to run in EV only mode. Pushing the toggle switch makes no difference. The only solution is to turn off our Audi, walk away for 10-15 minutes, then restart. It always restarts in EV only mode.

Our dealer states there is nothing in their shop tech manuals stating that the ICE starts on its own to lubricate the engine when something decides that is necessary. They believe it helps the PHEV to lubricate occasionally, but nothing exists in the software to cause that. They have not been able to determine the reason for automatically switching to battery hood or HEV mode. We believe it is another flaw in Audi/VW software or hardware.

We have not refueled in over 2 years, driving only EV. We always park our Audi in the garage when it is not in use. We are not in an extreme climate, though it does got hot here in the summer. When the ICE has suddenly started, it does it easily and without any hesitation or added noise, especially since the engine has only been used for about 5,500 miles since 2017, over the total 22K miles we have on our Audi.

We are also down to under 15 miles of range maximum, driving no faster than 45mph nearly all the time it is driven. We rarely drive on the freeway any more.
 

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