Skipping gears when paddle shifting
Discussion
While out on the Snowdonia run on Sunday I noticed an odd behaviour from my 2014 V12VS when upshifting in Manual mode.
A single pull on the + paddle would, on occasion not instigate a shift and on other occasions elicits two shifts - pull once , go up 2 gears.
I've spoken to one of our friendly Independents who suggested driving in in 'Drive' to see if same behaviour was seen - it was not. Aside from the clunky changes all gears were selected sequentially. [60 minute drive].
The current thinking is the paddle contacts are contaminated. I've done some sleuthing and found this thread :
https://www.6speedonline.com/forums/aston-martin/4...
However it draws no conclusions as to remedy.
Has anyone seen this before, or more importantly how was it fixed.
Thanks as ever for any feedback..
PS downshifts are fine
A single pull on the + paddle would, on occasion not instigate a shift and on other occasions elicits two shifts - pull once , go up 2 gears.
I've spoken to one of our friendly Independents who suggested driving in in 'Drive' to see if same behaviour was seen - it was not. Aside from the clunky changes all gears were selected sequentially. [60 minute drive].
The current thinking is the paddle contacts are contaminated. I've done some sleuthing and found this thread :
https://www.6speedonline.com/forums/aston-martin/4...
However it draws no conclusions as to remedy.
Has anyone seen this before, or more importantly how was it fixed.
Thanks as ever for any feedback..
PS downshifts are fine
Not something I've ever seen mentioned before, and certainly not something I've ever experienced, yet the thread you linked to implies it's not an isolated incident.
The thread makes interesting reading, with several of what look to me like "red herrings" offered as causes. I could give an opinion, but it would just be speculation based on reading plus applying a bit of logic.
But a question - were you pressing on a bit when this happened, or was the car well in the middle of the rev range? The reason I ask is that occasionally I'll get something like this on a downshift when the revs are low, but I know this is because I'm calling for a shift on the left paddle at the same time as the gearbox ECU is calling for a downshift to avoid the engine going out of its operating range, with the result I'll get a two-gear downshift from, say, 3rd to 1st. Which, if you're not expecting it, can be ......exciting.
The thread makes interesting reading, with several of what look to me like "red herrings" offered as causes. I could give an opinion, but it would just be speculation based on reading plus applying a bit of logic.
But a question - were you pressing on a bit when this happened, or was the car well in the middle of the rev range? The reason I ask is that occasionally I'll get something like this on a downshift when the revs are low, but I know this is because I'm calling for a shift on the left paddle at the same time as the gearbox ECU is calling for a downshift to avoid the engine going out of its operating range, with the result I'll get a two-gear downshift from, say, 3rd to 1st. Which, if you're not expecting it, can be ......exciting.
Hi LTP - thank you for responding
The issue is with upshifts - downshifts are fine.
I rarely go high in the rev range, I find there's sufficient torque to short-shift. On Sunday I was pressing on while on the B4391, lovely bit of tarmac.
Conversely when doing the 'Drive' testing I was low in the rev range and again got 2 upshifts on several occasions for a single pull on the paddle. Also one 'no shift'.
It's not gear dependant, I've seen 3 to 5, 4 to 6 and 5 to 7. It doesn't do it all the time and is interspersed with normal operation.
I may try the 'push the lever towards the centre line of thee steering wheel' suggested as its a no cost option. Other than that it sounds like I need to remove/dismantle the paddles.
The issue is with upshifts - downshifts are fine.
I rarely go high in the rev range, I find there's sufficient torque to short-shift. On Sunday I was pressing on while on the B4391, lovely bit of tarmac.
Conversely when doing the 'Drive' testing I was low in the rev range and again got 2 upshifts on several occasions for a single pull on the paddle. Also one 'no shift'.
It's not gear dependant, I've seen 3 to 5, 4 to 6 and 5 to 7. It doesn't do it all the time and is interspersed with normal operation.
I may try the 'push the lever towards the centre line of thee steering wheel' suggested as its a no cost option. Other than that it sounds like I need to remove/dismantle the paddles.
I appreciate your problem is with upshift - I only included my example in case there was a chance you and the ECU were calling for a shift at the same time and generating a double, but from what you say this can't be the case.
Disclaimer - I'm not an automotive electrical engineer but am a mechanical engineer who has worked in the automotive product development for more years than I care to remember, mainly in body & trim engineering and program management, so the following may not be definitive ... or even right.
I was curious about the design of the contacts in the composite picture in the 6SpeedOL thread, so I dug out an old Vantage workshop manual pdf to look at the circuit diagrams. These diagrams are from an early V8V, but I'm 99% sure that AML would not have changed the way the paddles work and are wired between the SSI in this manual, my SSII and your SSIII. I have no idea if the following will help you - please feel free to ignore.
Here's an extract from the wiring diagrams, showing the paddle shift switches - click on it to expand it
The red text shows where the wiring winds its way through the car and eventually ends up plugged into the gearbox ECU, the blue is the paddles. I was curious why there were three contacts each side in the 6SOL images - I was expecting two each side. It appears that the paddle switches basically operate by connecting a signal from the ECU to ground. There are four wires into the paddle switch assembly, coloured (I think) black (B), red (R), yellow with a red stripe (YR) and green (G). The ECU needs a signal to tell it a paddle has been pulled, and another signal to tell it which paddle. The YR is the "pull" signal, the G the "up" and R "down". So for an upshift from the RH paddle the switch will connect the YR and G to earth (B), and for a downshift from the LH it's YR and R to earth (B).
Why is this important? Because any short to earth might be interpreted as a request for a shift, but as a safety the ECU needs the two signals. So when you take the switchpack off the column it's worth checking for any possible cuts or tears in the insulation that could be touching anything metallic where the wiring moves with the column.
The second thing I noticed (and this is, in my opinion, a more likely cause) is that rather than a momentary static contact, the paddle switches have a "wiping" action of the fingers on the tracks on the circuit board, shown in yellow on the picture below (click to expand).
The Vantage paddles don't have a "snap" action, but have quite long travel during which the gearbox gets a signal. So you can pull a paddle and the gearbox shifts before the paddle reaches the end of its travel, the contact continuing to "wipe" as the paddle is pulled further onto the stop. So if a "finger" is not making a solid, continuous contact as it slides on the track and it skips and makes contact twice in one operation, this could be interpreted as a "double pull", which we know the SS gearbox ECU interprets as a request to immediately change two gears.
The other thing I noticed is the application of grease to the mechanical parts of the switch in the pictures appears to have been quite liberal, including getting onto the switch contacts on the circuit board (pink arrows). This should get wiped off during operation if there is sufficient contact pressure, but it might not and the grease is probably not conductive to avoid creating shorts. Again, an intermittent contact during operation due to grease could be interpreted as a request for a double shift.
So if I find myself in your position I'd be cleaning the contacts, making sure that there isn't excess grease, making sure all three fingers are making a nice contact with the circuit board and maybe applying a very light application of a contact lubricant to the contact pads (ensuring it can't short).
Hope this helps and I haven't been teaching you to suck eggs. Usual caveats that I may not actually know what I'm talking about.
This next bit is for any pedants that want to pick me up on my interpretation of the ECU signals going to ground (earth)
When the switch contacts aren't made the signal lines aren't "open", but there is a small signal as the connection is still going to ground via the resistors (10k ohm?) in parallel across each switch contact. When the switch is operated the contacts are made and short out these resistors, giving an increase in the signal to ground through the 470 ohm resistor, which the ECU will recognise as a demand. The small steady-state signal is probably used in diagnostics to detect a faulty switch, broken wire or a plug not correctly connected.
Disclaimer - I'm not an automotive electrical engineer but am a mechanical engineer who has worked in the automotive product development for more years than I care to remember, mainly in body & trim engineering and program management, so the following may not be definitive ... or even right.
I was curious about the design of the contacts in the composite picture in the 6SpeedOL thread, so I dug out an old Vantage workshop manual pdf to look at the circuit diagrams. These diagrams are from an early V8V, but I'm 99% sure that AML would not have changed the way the paddles work and are wired between the SSI in this manual, my SSII and your SSIII. I have no idea if the following will help you - please feel free to ignore.
Here's an extract from the wiring diagrams, showing the paddle shift switches - click on it to expand it
The red text shows where the wiring winds its way through the car and eventually ends up plugged into the gearbox ECU, the blue is the paddles. I was curious why there were three contacts each side in the 6SOL images - I was expecting two each side. It appears that the paddle switches basically operate by connecting a signal from the ECU to ground. There are four wires into the paddle switch assembly, coloured (I think) black (B), red (R), yellow with a red stripe (YR) and green (G). The ECU needs a signal to tell it a paddle has been pulled, and another signal to tell it which paddle. The YR is the "pull" signal, the G the "up" and R "down". So for an upshift from the RH paddle the switch will connect the YR and G to earth (B), and for a downshift from the LH it's YR and R to earth (B).
Why is this important? Because any short to earth might be interpreted as a request for a shift, but as a safety the ECU needs the two signals. So when you take the switchpack off the column it's worth checking for any possible cuts or tears in the insulation that could be touching anything metallic where the wiring moves with the column.
The second thing I noticed (and this is, in my opinion, a more likely cause) is that rather than a momentary static contact, the paddle switches have a "wiping" action of the fingers on the tracks on the circuit board, shown in yellow on the picture below (click to expand).
The Vantage paddles don't have a "snap" action, but have quite long travel during which the gearbox gets a signal. So you can pull a paddle and the gearbox shifts before the paddle reaches the end of its travel, the contact continuing to "wipe" as the paddle is pulled further onto the stop. So if a "finger" is not making a solid, continuous contact as it slides on the track and it skips and makes contact twice in one operation, this could be interpreted as a "double pull", which we know the SS gearbox ECU interprets as a request to immediately change two gears.
The other thing I noticed is the application of grease to the mechanical parts of the switch in the pictures appears to have been quite liberal, including getting onto the switch contacts on the circuit board (pink arrows). This should get wiped off during operation if there is sufficient contact pressure, but it might not and the grease is probably not conductive to avoid creating shorts. Again, an intermittent contact during operation due to grease could be interpreted as a request for a double shift.
So if I find myself in your position I'd be cleaning the contacts, making sure that there isn't excess grease, making sure all three fingers are making a nice contact with the circuit board and maybe applying a very light application of a contact lubricant to the contact pads (ensuring it can't short).
Hope this helps and I haven't been teaching you to suck eggs. Usual caveats that I may not actually know what I'm talking about.
This next bit is for any pedants that want to pick me up on my interpretation of the ECU signals going to ground (earth)
When the switch contacts aren't made the signal lines aren't "open", but there is a small signal as the connection is still going to ground via the resistors (10k ohm?) in parallel across each switch contact. When the switch is operated the contacts are made and short out these resistors, giving an increase in the signal to ground through the 470 ohm resistor, which the ECU will recognise as a demand. The small steady-state signal is probably used in diagnostics to detect a faulty switch, broken wire or a plug not correctly connected.
LTP said:
I appreciate your problem is with upshift - I only included my example in case there was a chance you and the ECU were calling for a shift at the same time and generating a double, but from what you say this can't be the case.
Disclaimer - I'm not an automotive electrical engineer but am a mechanical engineer who has worked in the automotive product development for more years than I care to remember, mainly in body & trim engineering and program management, so the following may not be definitive ... or even right.
I was curious about the design of the contacts in the composite picture in the 6SpeedOL thread, so I dug out an old Vantage workshop manual pdf to look at the circuit diagrams. These diagrams are from an early V8V, but I'm 99% sure that AML would not have changed the way the paddles work and are wired between the SSI in this manual, my SSII and your SSIII. I have no idea if the following will help you - please feel free to ignore.
Here's an extract from the wiring diagrams, showing the paddle shift switches - click on it to expand it
The red text shows where the wiring winds its way through the car and eventually ends up plugged into the gearbox ECU, the blue is the paddles. I was curious why there were three contacts each side in the 6SOL images - I was expecting two each side. It appears that the paddle switches basically operate by connecting a signal from the ECU to ground. There are four wires into the paddle switch assembly, coloured (I think) black (B), red (R), yellow with a red stripe (YR) and green (G). The ECU needs a signal to tell it a paddle has been pulled, and another signal to tell it which paddle. The YR is the "pull" signal, the G the "up" and R "down". So for an upshift from the RH paddle the switch will connect the YR and G to earth (B), and for a downshift from the LH it's YR and R to earth (B).
Why is this important? Because any short to earth might be interpreted as a request for a shift, but as a safety the ECU needs the two signals. So when you take the switchpack off the column it's worth checking for any possible cuts or tears in the insulation that could be touching anything metallic where the wiring moves with the column.
The second thing I noticed (and this is, in my opinion, a more likely cause) is that rather than a momentary static contact, the paddle switches have a "wiping" action of the fingers on the tracks on the circuit board, shown in yellow on the picture below (click to expand).
The Vantage paddles don't have a "snap" action, but have quite long travel during which the gearbox gets a signal. So you can pull a paddle and the gearbox shifts before the paddle reaches the end of its travel, the contact continuing to "wipe" as the paddle is pulled further onto the stop. So if a "finger" is not making a solid, continuous contact as it slides on the track and it skips and makes contact twice in one operation, this could be interpreted as a "double pull", which we know the SS gearbox ECU interprets as a request to immediately change two gears.
The other thing I noticed is the application of grease to the mechanical parts of the switch in the pictures appears to have been quite liberal, including getting onto the switch contacts on the circuit board (pink arrows). This should get wiped off during operation if there is sufficient contact pressure, but it might not and the grease is probably not conductive to avoid creating shorts. Again, an intermittent contact during operation due to grease could be interpreted as a request for a double shift.
So if I find myself in your position I'd be cleaning the contacts, making sure that there isn't excess grease, making sure all three fingers are making a nice contact with the circuit board and maybe applying a very light application of a contact lubricant to the contact pads (ensuring it can't short).
Hope this helps and I haven't been teaching you to suck eggs. Usual caveats that I may not actually know what I'm talking about.
This next bit is for any pedants that want to pick me up on my interpretation of the ECU signals going to ground (earth)
When the switch contacts aren't made the signal lines aren't "open", but there is a small signal as the connection is still going to ground via the resistors (10k ohm?) in parallel across each switch contact. When the switch is operated the contacts are made and short out these resistors, giving an increase in the signal to ground through the 470 ohm resistor, which the ECU will recognise as a demand. The small steady-state signal is probably used in diagnostics to detect a faulty switch, broken wire or a plug not correctly connected.
LTP - What can I say, thats absolutely amazing!! Above and beyond. Disclaimer - I'm not an automotive electrical engineer but am a mechanical engineer who has worked in the automotive product development for more years than I care to remember, mainly in body & trim engineering and program management, so the following may not be definitive ... or even right.
I was curious about the design of the contacts in the composite picture in the 6SpeedOL thread, so I dug out an old Vantage workshop manual pdf to look at the circuit diagrams. These diagrams are from an early V8V, but I'm 99% sure that AML would not have changed the way the paddles work and are wired between the SSI in this manual, my SSII and your SSIII. I have no idea if the following will help you - please feel free to ignore.
Here's an extract from the wiring diagrams, showing the paddle shift switches - click on it to expand it
The red text shows where the wiring winds its way through the car and eventually ends up plugged into the gearbox ECU, the blue is the paddles. I was curious why there were three contacts each side in the 6SOL images - I was expecting two each side. It appears that the paddle switches basically operate by connecting a signal from the ECU to ground. There are four wires into the paddle switch assembly, coloured (I think) black (B), red (R), yellow with a red stripe (YR) and green (G). The ECU needs a signal to tell it a paddle has been pulled, and another signal to tell it which paddle. The YR is the "pull" signal, the G the "up" and R "down". So for an upshift from the RH paddle the switch will connect the YR and G to earth (B), and for a downshift from the LH it's YR and R to earth (B).
Why is this important? Because any short to earth might be interpreted as a request for a shift, but as a safety the ECU needs the two signals. So when you take the switchpack off the column it's worth checking for any possible cuts or tears in the insulation that could be touching anything metallic where the wiring moves with the column.
The second thing I noticed (and this is, in my opinion, a more likely cause) is that rather than a momentary static contact, the paddle switches have a "wiping" action of the fingers on the tracks on the circuit board, shown in yellow on the picture below (click to expand).
The Vantage paddles don't have a "snap" action, but have quite long travel during which the gearbox gets a signal. So you can pull a paddle and the gearbox shifts before the paddle reaches the end of its travel, the contact continuing to "wipe" as the paddle is pulled further onto the stop. So if a "finger" is not making a solid, continuous contact as it slides on the track and it skips and makes contact twice in one operation, this could be interpreted as a "double pull", which we know the SS gearbox ECU interprets as a request to immediately change two gears.
The other thing I noticed is the application of grease to the mechanical parts of the switch in the pictures appears to have been quite liberal, including getting onto the switch contacts on the circuit board (pink arrows). This should get wiped off during operation if there is sufficient contact pressure, but it might not and the grease is probably not conductive to avoid creating shorts. Again, an intermittent contact during operation due to grease could be interpreted as a request for a double shift.
So if I find myself in your position I'd be cleaning the contacts, making sure that there isn't excess grease, making sure all three fingers are making a nice contact with the circuit board and maybe applying a very light application of a contact lubricant to the contact pads (ensuring it can't short).
Hope this helps and I haven't been teaching you to suck eggs. Usual caveats that I may not actually know what I'm talking about.
This next bit is for any pedants that want to pick me up on my interpretation of the ECU signals going to ground (earth)
When the switch contacts aren't made the signal lines aren't "open", but there is a small signal as the connection is still going to ground via the resistors (10k ohm?) in parallel across each switch contact. When the switch is operated the contacts are made and short out these resistors, giving an increase in the signal to ground through the 470 ohm resistor, which the ECU will recognise as a demand. The small steady-state signal is probably used in diagnostics to detect a faulty switch, broken wire or a plug not correctly connected.
Thank you so much for this. I'm going to get all the bits and pieces together and try to complete this myself. I will report back, but it may be a couple of weeks as the next few weekends are busy.
Thanks again, much appreciated!
Edited by CatalystV12V on Friday 2nd May 14:41
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