Vantage speedometer problem...
Discussion
Good morning everybody !
Here is my story:
I own a 09 V8 Vantage SS, all was perfect until few month ago, I started to receive speed fines for speeding on highway, which looked strange as I only drive with cruise control on highway, 4 years I’m driving here and never took a speeding fine…
So here I received the first fine for a supposed speeding 3 weeks before, at first I thought it could have been my mistake. But then I started to received fines once a day for a week. Speed limit was 120 and I alway put the cruise control on 110/115…
After few days I decided to take the car on a empty highway with another car. My thoughts were rights, when driving at 110km/h with cruise control, my friend was reading 123Km/h on his… 13km/h difference !! Knowing that’s not a 0,1km/h accurate I asked another friend to try the same test. Here again 12/13km/h difference… I straight called my AML garage to tell them, answer I got « Nope that’s impossible » I managed to get them to take the car and check.
After few days they called me to « explain to me about the speed », they sent me for a test drive with an engineer to show me what they found. The engineer plugged his toughbook on the OBD plug under the wheel and off we were. He showed me that he was reading only 2km/h slower on the OBD and therefore it was not a significant error. I then told him to open his eyes and look around, the car was showing 20km/h slower than speed limit but we were faster than all the traffic already. I then told him that if he was so sure we could have a bet « speed limit here is 120, I will drive 117, plus the 2 of error it will make 119, still 1 or 2 margin before taking the fine, if I got the ticket he will pay for it ». He then was less sure about the speed and decline the bet. I had a friend following us, I asked him to pull side by side again, both on cruise control and same 12km/h error reading !!
We went back to the dealer, the engineer said that the car was still showing only 2 difference. I then said he forgot to mention about the other car speed… I explained that firstly the computer is plugged on the same source as the speedo, therefore if there is a reading problem for the car how can we assume the computer is right also? Then I said the engineer witnessed the speed difference. I got the funniest response I had in year « You cannot compare speed with another car, not same model, not same wheel size »… Ah… Speed is therefore relative to the size of the car then… Good to know !
I therefore challenged them to do the same test with one of their car, it wouldn’t be too difficult to found the same year Vantage… After hard negotiations, they accepted to take one of their car for the test. Off we went again. Guess what ? 12km/h difference in reading again ! This time with 3 AML technicians witnesses.
Back to the garage the manager came to see what was happening. One of his employee explained the situation, answer : « not you can’t do it like this, this is not a AML approved technic, the computer is the one we can use » I then told him he could just use a Dyno and he will get fixed once for all. « sorry we don’t have a dyno »
Seeing that all the employees were kind of all approving what I said I had to ask once again, this time it will be different, he will drive my car, his technician will drive another car again and he will see from his own eyes. Off we went once again. At 88km/h in a new vanquish the Vantage was reading 80. At 110 Vanquish, 99 Vantage.
We went back to the garage. The manager could only agreed something was wrong but still told me how strange it was because the computer was not showing that. I had to explain again that taking the info from the same sources couldn’t be accepted as accurate… And I also got a funny « Oh that’s strange, someone with the same model complained about the same thing last week, we showed him on the computer and he went back home »….
I send left the car there… 1 day, 2 days, 1 week, 2 week, 3 weeks, 24 days later still no clue about what was happening ! I’ve been told that they couldn’t found the problem and worst that they couldn’t even acknowledge it because they couldn’t prove it ! They refused to rent a dyno, and the videos the crew took were not receivable by factory. So everybody agree there is a problem but nobody want to acknowledge it ? What a nerve cracking situation. Of course no courtesy car provided… So I paid thousand of AED in fines and I’m left here using the cab…
I went to see the manager once again, he told me they couldn’t understand the problem, they tried to change wheels/tires etc etc, and that they tried with GPS to see the readings. GPS was showing between 2 and 3 km/h difference. I asked him to confirm that they found my car under reading the GPS by 2 or 3 witch he did. I then explained to him that by law the speedometer could NEVER read less than actual speed! For obvious safety reasons. He was not aware of it. So it cost me s***t load of money, I spend a considerably amount of time there, I had to ARGUE and FORCE them to do the driving test witch showed I was right, and now I also have to do researches for them. Great.
( for reference : The speed indicated shall not be less than the true speed of the vehicle. At the test speeds specified in paragraph 5.2.5. above, there shall be the following relationship between the speed displayed (V1) and the true speed (V2). 0 = (V1-V2) = 0.1 V2 + 4 km/h
http://www.unece.org/fileadmin/DAM/trans/main/wp29... )
The car is still there, the problem was shown on the 16th August 2015, we are the 7th October. Nearly 2 months, still using taxi because they can’t provide any courtesy car. What a poor experience of Aston Martin, I was not expecting this kind of problems with such a brand. I would just like to underline that one of the employee has been trying to be particularly helping but he apparently can’t do much about it. I’m left here with no car, no solution to a safety related issue, in a nerves breaking and incredibly frustrating situation. Unbelievable.
Anyone with a similar issue ? Any tip is welcome...
Here is my story:
I own a 09 V8 Vantage SS, all was perfect until few month ago, I started to receive speed fines for speeding on highway, which looked strange as I only drive with cruise control on highway, 4 years I’m driving here and never took a speeding fine…
So here I received the first fine for a supposed speeding 3 weeks before, at first I thought it could have been my mistake. But then I started to received fines once a day for a week. Speed limit was 120 and I alway put the cruise control on 110/115…
After few days I decided to take the car on a empty highway with another car. My thoughts were rights, when driving at 110km/h with cruise control, my friend was reading 123Km/h on his… 13km/h difference !! Knowing that’s not a 0,1km/h accurate I asked another friend to try the same test. Here again 12/13km/h difference… I straight called my AML garage to tell them, answer I got « Nope that’s impossible » I managed to get them to take the car and check.
After few days they called me to « explain to me about the speed », they sent me for a test drive with an engineer to show me what they found. The engineer plugged his toughbook on the OBD plug under the wheel and off we were. He showed me that he was reading only 2km/h slower on the OBD and therefore it was not a significant error. I then told him to open his eyes and look around, the car was showing 20km/h slower than speed limit but we were faster than all the traffic already. I then told him that if he was so sure we could have a bet « speed limit here is 120, I will drive 117, plus the 2 of error it will make 119, still 1 or 2 margin before taking the fine, if I got the ticket he will pay for it ». He then was less sure about the speed and decline the bet. I had a friend following us, I asked him to pull side by side again, both on cruise control and same 12km/h error reading !!
We went back to the dealer, the engineer said that the car was still showing only 2 difference. I then said he forgot to mention about the other car speed… I explained that firstly the computer is plugged on the same source as the speedo, therefore if there is a reading problem for the car how can we assume the computer is right also? Then I said the engineer witnessed the speed difference. I got the funniest response I had in year « You cannot compare speed with another car, not same model, not same wheel size »… Ah… Speed is therefore relative to the size of the car then… Good to know !
I therefore challenged them to do the same test with one of their car, it wouldn’t be too difficult to found the same year Vantage… After hard negotiations, they accepted to take one of their car for the test. Off we went again. Guess what ? 12km/h difference in reading again ! This time with 3 AML technicians witnesses.
Back to the garage the manager came to see what was happening. One of his employee explained the situation, answer : « not you can’t do it like this, this is not a AML approved technic, the computer is the one we can use » I then told him he could just use a Dyno and he will get fixed once for all. « sorry we don’t have a dyno »
Seeing that all the employees were kind of all approving what I said I had to ask once again, this time it will be different, he will drive my car, his technician will drive another car again and he will see from his own eyes. Off we went once again. At 88km/h in a new vanquish the Vantage was reading 80. At 110 Vanquish, 99 Vantage.
We went back to the garage. The manager could only agreed something was wrong but still told me how strange it was because the computer was not showing that. I had to explain again that taking the info from the same sources couldn’t be accepted as accurate… And I also got a funny « Oh that’s strange, someone with the same model complained about the same thing last week, we showed him on the computer and he went back home »….
I send left the car there… 1 day, 2 days, 1 week, 2 week, 3 weeks, 24 days later still no clue about what was happening ! I’ve been told that they couldn’t found the problem and worst that they couldn’t even acknowledge it because they couldn’t prove it ! They refused to rent a dyno, and the videos the crew took were not receivable by factory. So everybody agree there is a problem but nobody want to acknowledge it ? What a nerve cracking situation. Of course no courtesy car provided… So I paid thousand of AED in fines and I’m left here using the cab…
I went to see the manager once again, he told me they couldn’t understand the problem, they tried to change wheels/tires etc etc, and that they tried with GPS to see the readings. GPS was showing between 2 and 3 km/h difference. I asked him to confirm that they found my car under reading the GPS by 2 or 3 witch he did. I then explained to him that by law the speedometer could NEVER read less than actual speed! For obvious safety reasons. He was not aware of it. So it cost me s***t load of money, I spend a considerably amount of time there, I had to ARGUE and FORCE them to do the driving test witch showed I was right, and now I also have to do researches for them. Great.
( for reference : The speed indicated shall not be less than the true speed of the vehicle. At the test speeds specified in paragraph 5.2.5. above, there shall be the following relationship between the speed displayed (V1) and the true speed (V2). 0 = (V1-V2) = 0.1 V2 + 4 km/h
http://www.unece.org/fileadmin/DAM/trans/main/wp29... )
The car is still there, the problem was shown on the 16th August 2015, we are the 7th October. Nearly 2 months, still using taxi because they can’t provide any courtesy car. What a poor experience of Aston Martin, I was not expecting this kind of problems with such a brand. I would just like to underline that one of the employee has been trying to be particularly helping but he apparently can’t do much about it. I’m left here with no car, no solution to a safety related issue, in a nerves breaking and incredibly frustrating situation. Unbelievable.
Anyone with a similar issue ? Any tip is welcome...
Edited by bazderome on Thursday 8th October 06:10
First time that I have heard of an under reading speedo on this forum.
You mentioned in the test with another car, a difference of about 10%, but of course the other car speedo would probably not be precise.
Then you mentioned the test that I had immediately thought of, GPS. You say there was then only a slight discrepancy, albeit under, which is not allowed.
Perhaps the only positive comment to make, is that you are lucky not to be in the UK. You would have lost your money and your driving licence by now.
The mechanic checking your speedo by plugging his laptop into your OBDII is comical. We trust these guys to work on our cars?
I'm not familiar with how the speedo works on an Aston. However, it's probably an ABS speed sensor as mentioned. These work by having a pickup mounted next to a toothed rotor, buried in the hub assembly. I would guess yours is corroded so not all of the teeth are being detected as it rotates. As the number of missing teeth is consistent you get a consistent under read.
Everything else is just software so it has to be the sensor or rotor.
I'm not familiar with how the speedo works on an Aston. However, it's probably an ABS speed sensor as mentioned. These work by having a pickup mounted next to a toothed rotor, buried in the hub assembly. I would guess yours is corroded so not all of the teeth are being detected as it rotates. As the number of missing teeth is consistent you get a consistent under read.
Everything else is just software so it has to be the sensor or rotor.
Edited by Johnny42 on Thursday 8th October 10:12
It's very disappointing that the garage couldn't figure out that using the computer to compare with the speedo is like a school child marking their own homework.
Just one question - are you on wheels and tyres with the same rolling circumference as standard? I'm not sure of the maths of this, but I I think that non-standard sizes could cause this sort of problem in theory
Just one question - are you on wheels and tyres with the same rolling circumference as standard? I'm not sure of the maths of this, but I I think that non-standard sizes could cause this sort of problem in theory
emicen said:
Does "wheels, tires etc etc" include ABS sensors and ABS module?
I just asked them I will let you know their answer, the only thing is they showed me with the computer they read the speed from few different sensors, something like 5 or 7 different ones, so I guess it would have show only one sensor failing if that was the case? djmac56 said:
It's very disappointing that the garage couldn't figure out that using the computer to compare with the speedo is like a school child marking their own homework.
Just one question - are you on wheels and tyres with the same rolling circumference as standard? I'm not sure of the maths of this, but I I think that non-standard sizes could cause this sort of problem in theory
If it wasn't about my car I would have laugh too ! Just one question - are you on wheels and tyres with the same rolling circumference as standard? I'm not sure of the maths of this, but I I think that non-standard sizes could cause this sort of problem in theory
For the wheels and tires they are the exact same size, but to be sure they changed all my wheels and fitted factory ones, still under reading ...Johnny42 said:
The mechanic checking your speedo by plugging his laptop into your OBDII is comical. We trust these guys to work on our cars?
I'm not familiar with how the speedo works on an Aston. However, it's probably an ABS speed sensor as mentioned. These work by having a pickup mounted next to a toothed rotor, buried in the hub assembly. I would guess yours is corroded so not all of the teeth are being detected as it rotates. As the number of missing teeth is consistent you get a consistent under read.
Everything else is just software so it has to be the sensor or rotor.
As said just before I asked them to confirm for the ABS, from the computer they can see from few different places, if I remember well they read from wheels, engine speed etc, they were showing around 2 km/h difference, still just a bit slower than the GPSI'm not familiar with how the speedo works on an Aston. However, it's probably an ABS speed sensor as mentioned. These work by having a pickup mounted next to a toothed rotor, buried in the hub assembly. I would guess yours is corroded so not all of the teeth are being detected as it rotates. As the number of missing teeth is consistent you get a consistent under read.
Everything else is just software so it has to be the sensor or rotor.
Edited by Johnny42 on Thursday 8th October 10:12
The worst is that they couldn't understand my concern about the OBDII...
Edited by bazderome on Thursday 8th October 11:33
GPS is surely the best way to resolve this.
Get in the car with a variety of phones and GPS devices
Starts they all up using different programs
Set Cruise to a certain speed.
See if the Cruise Speed matches or is relatively near the GPS indicated speed.
If it is not, then you have a problem.
Get in the car with a variety of phones and GPS devices
Starts they all up using different programs
Set Cruise to a certain speed.
See if the Cruise Speed matches or is relatively near the GPS indicated speed.
If it is not, then you have a problem.
Most GPS device manufacturers quite an error range of 0.1 to 0.5MPH so any GPS measurement is going to be better than a car speedo which is usually set to read high. GPS measures the doppler shift of the received signal to calculate the speed so it is not affected by going up or down hills etc.
There is a nice vid that compares a couple of mobile phone GPS speed apps, a car speedo and also one of those active speed warning signs https://www.youtube.com/watch?t=55&v=YJ7MesSo2...
There is a nice vid that compares a couple of mobile phone GPS speed apps, a car speedo and also one of those active speed warning signs https://www.youtube.com/watch?t=55&v=YJ7MesSo2...
He's done that - he said GPS reads 2-3 km/h more than indicated - ie he's under reading a fraction.
So what we'got is a car that is virtually exactly right to GPS but all the other cars are 10 km/h or more out.
While its technically illegal I'm not sure I'd be blaming that for speeding tickets. The UK tolerance for what its worth is 10%+2 mph of the speed limit so you'd not be done for that kind of margin of error. Its less than the thickness of the needle (I know Astons have a digital read out, but other cars don't).
So what we'got is a car that is virtually exactly right to GPS but all the other cars are 10 km/h or more out.
While its technically illegal I'm not sure I'd be blaming that for speeding tickets. The UK tolerance for what its worth is 10%+2 mph of the speed limit so you'd not be done for that kind of margin of error. Its less than the thickness of the needle (I know Astons have a digital read out, but other cars don't).
Not sure that there is a problem.
My Vantage Roadster speedo read just 1km/h less than the speed indicated on my garmin gps during my 2500 mile trip around Europe last month! Didn't get a French speeding fine.
It also reads exactly the same MPH as the garmin indicates when on UK roads. My DD Mercedes reads just 2 Mph slower with the same garmin GPS.
I like the fact that when I set the cruise control to 50mph in the M1 roadworks, I pass MOST of the other cars and not get a ticket!
My Vantage Roadster speedo read just 1km/h less than the speed indicated on my garmin gps during my 2500 mile trip around Europe last month! Didn't get a French speeding fine.
It also reads exactly the same MPH as the garmin indicates when on UK roads. My DD Mercedes reads just 2 Mph slower with the same garmin GPS.
I like the fact that when I set the cruise control to 50mph in the M1 roadworks, I pass MOST of the other cars and not get a ticket!
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