Hello all, should have joined this forum ages ago being a Peugeot nut and having had loads of them.
Would be very grateful if anyone could help with a weighty problem. Just bought a 1998 406 automatic and noticed very early on that occasionally the sport and winter lights flashed simultaneously. Unfortunately not konwing anything about this particular box I didn't know how serious it might be.
A transmission specialist has scanned it and said the gearbox oil is black/knackered (although has no 'bits' in it), and it has fault codes 48 (Park Neutral switch), 68 (Pressure Control) and 28 (Output speed signal).
Specialist A reckons it will definately need a new valve body at £795 but should be OK after that, specialist B said he wouldn't spend a penny on it as the box is probably shot. Strange thing is it drives beautifully and has only done 60,000.
I'm tempted just to change the oil and see if this will stop it flashing, anyone here offer me any advice? Having just spent £800 on a car I can't face the fact it may be useless!
Cheers
406 automatic AL4 gearbox problem
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OnlineCitroJim
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Hi Carlo14 and welcome to the forum 
Specialist A is clearly not one and Specialist B may be nearer the mark but may not be. There are things to check and do first.
Oil in the AL4 will look horrible after a while and as long as it has no bits in it and does not smell burned, the 'box will live for a while longer.
The fault codes suggest your gear position switch needs a clean-up, the code 68 that the oil pressure is a little low and the third may be a red herring. How did he read these codes as I suspect they were not read using the pukka Pug DIAG2000/ Cit Lexia diagnostic kit which will tell you far more in text and not by fault numbers.
Change the oil soonest but note there is a special procedure to do this and not all of it can be drained as the torque convertor holds a large quantity that cannot be drained.
The guide on how to do this is in a post in the Citroen forum but here it is again:
AL4 Oil Change Guide
Note very carefully that this operation must be carried out at 60 degrees C and even more importanly, you must only use ESSO LT71141 oil. NEVER use ordinary Dexron ATF as this WILL kill the 'box! Esso LT is golden in colour and looks like ordinary engine oil.
Esso LT71141 looks like liquid gold and costs roughly the same. It is expensive and best bought in a 20L drum, especially if you do a succession of partial changes.
As it's impossible to fully drain the 'box. I'd carry out at least three partial changes in reasonably quick succession.
It's not a bad idea to replace the oil filter but that's a gearbox off and strip apart job. Not trivial at all.
After the oil is changed, you must then have the oil wear indicator reset and this can only be done using a DIAG2000 or a Lexia. If the oil wear indicator trips, the sport and snow lights will flash and the gearbox will enter "limp Home" or "emergency 3rd" mode where the only gears available is third and reverse.
The AL4 is verty similar to the ZF 4HP20 and much the same applies. there is plenty written in this forum on the 4HP20, including how to strip one!
If you want to delve further into the wonderful world of autoboxes, I have a load of valuable information on the AL4.
Specialist A is clearly not one and Specialist B may be nearer the mark but may not be. There are things to check and do first.
Oil in the AL4 will look horrible after a while and as long as it has no bits in it and does not smell burned, the 'box will live for a while longer.
The fault codes suggest your gear position switch needs a clean-up, the code 68 that the oil pressure is a little low and the third may be a red herring. How did he read these codes as I suspect they were not read using the pukka Pug DIAG2000/ Cit Lexia diagnostic kit which will tell you far more in text and not by fault numbers.
Change the oil soonest but note there is a special procedure to do this and not all of it can be drained as the torque convertor holds a large quantity that cannot be drained.
The guide on how to do this is in a post in the Citroen forum but here it is again:
AL4 Oil Change Guide
Note very carefully that this operation must be carried out at 60 degrees C and even more importanly, you must only use ESSO LT71141 oil. NEVER use ordinary Dexron ATF as this WILL kill the 'box! Esso LT is golden in colour and looks like ordinary engine oil.
Esso LT71141 looks like liquid gold and costs roughly the same. It is expensive and best bought in a 20L drum, especially if you do a succession of partial changes.
As it's impossible to fully drain the 'box. I'd carry out at least three partial changes in reasonably quick succession.
It's not a bad idea to replace the oil filter but that's a gearbox off and strip apart job. Not trivial at all.
After the oil is changed, you must then have the oil wear indicator reset and this can only be done using a DIAG2000 or a Lexia. If the oil wear indicator trips, the sport and snow lights will flash and the gearbox will enter "limp Home" or "emergency 3rd" mode where the only gears available is third and reverse.
The AL4 is verty similar to the ZF 4HP20 and much the same applies. there is plenty written in this forum on the 4HP20, including how to strip one!
If you want to delve further into the wonderful world of autoboxes, I have a load of valuable information on the AL4.
Jim
Runner, cyclist, time triallist, duathlete, Citroen AX fan and the CCC Citroenian 'From A to Z' Columnist...
Runner, cyclist, time triallist, duathlete, Citroen AX fan and the CCC Citroenian 'From A to Z' Columnist...
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OnlineCitroJim
- A very naughty boy
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- Joined: 30 Apr 2005, 23:33
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- x 6182
- Contact:
Carlo,
One other thing i meant to mention is that if you have a proper DIAG2000/Lexia diagnosis carried out, it will tell you if any faults are permanant or intermittent. I reckon you'll find yours are intermittent and hopefully will clear and not return..
You may find this post interesting and useful. I meant to post it last night but the old brain was feeling a bit addled after a long day at work...
One other thing i meant to mention is that if you have a proper DIAG2000/Lexia diagnosis carried out, it will tell you if any faults are permanant or intermittent. I reckon you'll find yours are intermittent and hopefully will clear and not return..
You may find this post interesting and useful. I meant to post it last night but the old brain was feeling a bit addled after a long day at work...
Jim
Runner, cyclist, time triallist, duathlete, Citroen AX fan and the CCC Citroenian 'From A to Z' Columnist...
Runner, cyclist, time triallist, duathlete, Citroen AX fan and the CCC Citroenian 'From A to Z' Columnist...
Cheers Jim
One thing I have noticed on mine is that when the sport and winter lights are flashing I still have use of all 4 gears, whereas I thought that also meant reduced functionality, i.e. 3rd gear only.
Also looking at this thread am I wrong to assume that this flashing can mainly indicate the oil just needs replacing, or am I misunderstanding something?
http://www.savewalcotlibrary.co.uk/foru ... &view=next
Am getting the oil changed next week anyway.
One thing I have noticed on mine is that when the sport and winter lights are flashing I still have use of all 4 gears, whereas I thought that also meant reduced functionality, i.e. 3rd gear only.
Also looking at this thread am I wrong to assume that this flashing can mainly indicate the oil just needs replacing, or am I misunderstanding something?
http://www.savewalcotlibrary.co.uk/foru ... &view=next
Am getting the oil changed next week anyway.