I have a Vectra Design (April 2006) 1.9 CDTI (!50PS) automatic saloon. After 24.5K miles the gearbox started to make "jerky" changes when changing down when up to working temperature. This only happened when under load and from 6th to 5th or 5th to 4th, but not on the overrun, i.e. changing down under braking, or when just slowing down. On one occasion I used manual override to change from 6th to 5th and I was left with no drive to the wheels, the engine on maximum revs (it was in cruise control) and doing 70mph in the outside lane.
The cas has spent 4 weeks with the Vauxhall dealer in which time it has a new gearbox, a new ECU and then another new gearboxes fitted before the dealer believed that the problem had been fixed. All of this work was done under warranty with guidance from Vauxhall technical support and included about 180 miles of testing. Having got the car back I am not convinced that the problem is fixed, except that it may now happen and slow speeds, e.g. in a slow moving queue, or when accelerating from slow speed, e.g after a roundabout.
Does anybody know what could be causing this kind of problem? Why would it change from higher speeds to low speed?
slt
Edited by Pugugly {P} on 25/11/2007 at 22:11
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I shouldn't really be promoting another forum, but I really think you need one that's more dedicated to your car, and somebody *hopefully* on there who is able to help with your question as they themselves may have / had the same kind of problems you're experiencing.
www.vectra-c.com
Edited by Dynamic Dave on 26/11/2007 at 00:30
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Thanks for your advice, but I have not had any response from posting the problem on the Vectra C forum either.
The latest news is that the car has been tested by an independent assessor who says that the problem still exists. It is now back with the dealer and discussions are going on with Vauxhall about what to do next. It is a leased car, so the leasing company in involved and is talking about rejecting the car as the problem cannot be fixed.
For me this is very sad. It was a great car and the autobox worked very well for the first 24000 miles. I am also disappointed that nobody appears to have any interest in the problem. Perhaps cars are becoming a mass-produced commodity (like televisions, computers, etc.) so when they go wrong you just throw them away, or sell them so that somebody else can have the problem.
My other complaint is that good old fashioned engineering seems to have taken second place to computers and software in cars. For this particular problem my own thoughts are that it is a heat-soak problem affecting the mechanical operation of the gearbox which "playing" with the gearbox software will not fix. But then I am only the driver!!
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Before changing gear, the gearbox should signal its intention to do so. The engine controller should then reduce torque for a while - giving a smooth shift. Then once the shift is over, the gearbox should tell the engine, and the engine torque should be re-instated. In short, there's almost a handshaking procedure between engine and gearbox during a shift, to make the shift as smooth as possible.
So, the question I would be wanting to find out is - does the gearbox actually send this message onto the CAN bus before these dodgy shifts? Going just a little further, as this will be on the high speed CAN bus, the integrity and terminations of the entire high speed CAN bus are worth checking - on some Vactras, there have been problems with corrosion in the high speed CAN bus wiring near the ABS unit.
Number_Cruncher
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On a similar note.... I have an old soldier Vectra B 2.0 XEV with auto box. I know its all different, much older etc, and mine actually works very well & changes smoothly. But it was much improved after gearbox oil was flushed & changed prophelactycally (?). The engineer I go to "does" auto boxes and says he has resolved a few puzzlers by changing or flushing & changing auto gb oil.
Worth a mention as Vauxhall dealers have never recommended gb oil change for my heap, despite it going every year, wheraes the service book lists a gb oil change.
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I think NC is on the right track. You car has had a new TCM and two new gearboxes - I would start looking at the engine management system and particularly the communication between ECM and TCM. It could be the CAN or it could be some other problem, but the workshop should be able to diagnose by looking at live data from the engine during gearshift.
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>>You car has had a new TCM and two new gearboxes
Yes, that was the info that made me think that looking elsewhere might be worthwhile!
Number_Cruncher
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I am surprised after TWO gearboxes that they have not thought along these lines. I once had a turbo problem on my 1.8T Passat (on delivery) and the garage insisted on changing the gearbox.
I don't think garages have that many staff who can trouble shoot things properly and go for the "swap the part" especially as they claim the time on the warranty repairs.
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It may not be a lot of consolation to rapb but I have had exactly the same problem. Same car, about 32k miles. It lost drive completely on the motorway and I had to have the car recovered to a Vauxhall garage. They replaced the ECU and returned it but the same thing happened after 10 miles. They then replaced the gearbox. It took about 3 weeks under instruction from Vauxhall.
It works now but occasionally (about once every few hundred miles) it gets a gear change wrong. Either it goes into neutral and then finds the gear with a sharp thump or just changes unexpectedly.
The trouble with something like this is it's bound not to happen if the Vauxhall garage take it out for a test drive and now its just out of the 3 year warranty.
Someone at Vauxhall HQ knows about this weakness and isn't telling us!
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