My 2Litre C-Max Powershift gearbox changes up, when climbing gradients, then changes back down again. This happens repeatedly even when the throttle is held constant. The revs also fluctuate by about 300 RPM when traveling straight and level on the motorway on a constant throttle. Has anyone else experienced this, or have any idea what the problem might be?
Powershift gearbox problems
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Well ive got a 2.0 tdcipowershift auto box too it sounds pretty normal changing gears on hills etc this is to maintain speed and engine strain etc mine does it to be honest In fact in wales at weekend it went down 2 gears to maintain my speed up a mountain hill taking it upto 3k revs which was a little noisy.As for motorways mine does it sometimes too but this is on slight hills etc.Does it do it when the engine is cold by any chance could just be the engine warming up etc and the engine management system settling down.
Thanks for the response Baldy.
It's more a case of continually changing up and then changing back down again. It seems to think it can manage a higher gear then finds the revs drop too low and it changes back down, then does it again, and again and again. Warranty is up at the end of August, so this is a concern.
On the motorway the revs increase by 300/400 RPM and drop back, then repeat this every 5 seconds or so. The vehicle speed is constant and on level road. In the old days of carbs, it would have been described as "hunting".
It's more a case of continually changing up and then changing back down again. It seems to think it can manage a higher gear then finds the revs drop too low and it changes back down, then does it again, and again and again. Warranty is up at the end of August, so this is a concern.
On the motorway the revs increase by 300/400 RPM and drop back, then repeat this every 5 seconds or so. The vehicle speed is constant and on level road. In the old days of carbs, it would have been described as "hunting".
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It's probably worth just having it checked
I found this about how it operates but it doesn't actually say how the clutch operation is controlled. I would have expected a combination of throttle position and engine speed. hink it must also use a road speed sensor or else it would not change down ( or if it did would always select the 1st & 2nd pair)
If any of the "Ford" owners have any insight as to the control method please share it. I'm now interested to know
Ford PowerShift transmission
<DIV =BTIarticle>
<DIV =BTIarticleText>Combining precision and ease, Ford PowerShift is a sophisticated six-speed automated manual transmission. It offers the smooth, effortless operation of an automatic transmission whilst giving you the precise control of a conventional manual transmission.
<DIV =BTIarticleText>
<DIV =BTIRow>
<DIV =BTIOneItem>
<DIV =BTIarticleTitle>How it works
<DIV =BTIarticle>
<DIV =BTIarticleText>The Ford Powershift automatic transmission uses two 3-speed gearboxes connected via a pair of clutches. When drive is selected, transmission #1 engages 1st gear and transmission #2 selects 2nd. Clutch #1 engages and the car pulls away in first. When it's time to change gear, it uses clutch #2 to swap transmission, with #1 immediately pre-selecting 3rd etc
I found this about how it operates but it doesn't actually say how the clutch operation is controlled. I would have expected a combination of throttle position and engine speed. hink it must also use a road speed sensor or else it would not change down ( or if it did would always select the 1st & 2nd pair)
If any of the "Ford" owners have any insight as to the control method please share it. I'm now interested to know
Ford PowerShift transmission
<DIV =BTIarticle>
<DIV =BTIarticleText>Combining precision and ease, Ford PowerShift is a sophisticated six-speed automated manual transmission. It offers the smooth, effortless operation of an automatic transmission whilst giving you the precise control of a conventional manual transmission.
<DIV =BTIarticleText>
<DIV =BTIRow>
<DIV =BTIOneItem>
<DIV =BTIarticleTitle>How it works
<DIV =BTIarticle>
<DIV =BTIarticleText>The Ford Powershift automatic transmission uses two 3-speed gearboxes connected via a pair of clutches. When drive is selected, transmission #1 engages 1st gear and transmission #2 selects 2nd. Clutch #1 engages and the car pulls away in first. When it's time to change gear, it uses clutch #2 to swap transmission, with #1 immediately pre-selecting 3rd etc
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3,966 Posts
Just found a bit more from an old Ford press
The secret behind PowerShift's smooth and frugal performance is the use of two electronically-controlled clutch units, which ensure seamless delivery of power to the wheels.
The two clutches each control what are effectively separate three-speed gearboxes. When the driver selects "D", first gear is selected in gearbox one and second gear is pre-selected in gearbox two.
As the throttle is applied, the clutch is engaged electronically and the car pulls away in first gear. At the appropriate moment drive is switched automatically to the pre-selected second gear and third gear is pre-selected in gearbox one.
Gearbox one contains first, third and fifth gears, while gearbox two consists of second, fourth and sixth. Sophisticated electronic control enables gears to be pre-selected according to whether the car is accelerating or decelerating
the diesel fuel systems are fly by wire and the fuel pump is controlled by the voltage difference that the ECU sees as a function of the accelerator position compared to the value in the "map" for the particular engine speed /load conditions
I just wonder if you have a slight problem with either the accelerator pedal variable resistance postion sensor or at least the connection to it
The secret behind PowerShift's smooth and frugal performance is the use of two electronically-controlled clutch units, which ensure seamless delivery of power to the wheels.
The two clutches each control what are effectively separate three-speed gearboxes. When the driver selects "D", first gear is selected in gearbox one and second gear is pre-selected in gearbox two.
As the throttle is applied, the clutch is engaged electronically and the car pulls away in first gear. At the appropriate moment drive is switched automatically to the pre-selected second gear and third gear is pre-selected in gearbox one.
Gearbox one contains first, third and fifth gears, while gearbox two consists of second, fourth and sixth. Sophisticated electronic control enables gears to be pre-selected according to whether the car is accelerating or decelerating
the diesel fuel systems are fly by wire and the fuel pump is controlled by the voltage difference that the ECU sees as a function of the accelerator position compared to the value in the "map" for the particular engine speed /load conditions
I just wonder if you have a slight problem with either the accelerator pedal variable resistance postion sensor or at least the connection to it
As you know (if you've driven any other auto) it shouldn't do what you describe. Hunting like that is just wrong. Other boxes don't suffer from this (I've been driving autos for 25 yrs), though it may be that all Powershift boxes do - I don't know.
It sounds like the electonic control needs some tuning to prevent the hunting.
Good luck
It sounds like the electonic control needs some tuning to prevent the hunting.
Good luck
Gents, Thanks for your responses. I had a dealer look at it and they found no fault but they updated some software. This didn't seem to make much difference. However, I drove it in manual for a few miles and, when I switched back to auto, it has become much more stable. The hunting has gone and it doesn't shift so erratically. No idea why this has happened, it just has. Weird.
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I have same issues been told recon gearbox and cost is around 3k 😌
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