Scary things happening with my 406 auto

[Dan the Man]

I've combed the web looking for answers, and can’t even find a similar fault description, hope someone here can help. I drive an auto ’98 406 that seems a little temperamental. Every time I drive her after she has been sitting for 5 hours plus, the gearbox spits the dummy. Usually within the first minute or so it will suddenly shudder like I’ve just dropped both front wheels into a ditch, the revs will jump to around 3500, and the sport and snow lights begin to flash. If I drive her for a few minutes like this, then switch the electrics off and back on again, the gearbox resets itself, and she gives me no grief for the rest of the trip.

I’ve had a few different gearbox companies give me their diagnosis, and I’ve been told everything from “It’s a $2 switch and a half hour job” through to “we’ll have to re-build the gear box and it’ll cost around $3000” As you might be able to tell, I’m a little confused.

Anyone got any clues as to what it is and what is required to fix it?

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[68 404]

There's a thread from a Pug site in the UK. Might find some follow up there.

http://www.peugeot406coupe.com/phpBB...hlight=problem

Dave

[SLC206]

Would that be a 2.0L petrol or a 3.0L V6?

[steve V6]

Dan,
When the snow/sport light flash that indicates a few things. Could be low oil level. Or just the g/box needs an oil change. The g/box ECU has an oil counter in it. When the counter recahes a preset count it will flash the two lights to indicate oil change time.

First have the oil changed. Pug oil is about $30/L (ouch). Or Castrol Transmax Z can be used at around $15/L.

Does your car have a 2 ltre motor or the 3 ltre V6. The 2 ltre motor uses the AL4 auto not very reliable. The V6 uses the 4HP20 g/box that is much more relaible. Has your car travelled less than 100,000kms or more than 150,000kms?

If your car has less than 100,000kms and is the V6 the g/box should still be ok. If it is the 2 ltre auto then the auto could need to be overhauled.

Withe the 4HP20 auto if the ECU detects a major problem the ECU limits the motor to 2,000 revs. Is this happening?

[Alan S]

Apparently, there is an ECU attached to a 4HP20
If so then a trip to a dealer for a software update is the starting point.

FYI, from the ZF service manual.

Control
This is provided by:
• the hydraulic unit,
• the ECU,
• the control cable.
Points of note
• Lock-up of 2nd, 3rd and 4th gears with controlled slip.
• Electronic management of all regulation and gear changing functions.
• Multiple programs: auto-adaptive (DSP) - Sport-Snow.
• Gears and programs displayed on dashboard.
• Possibility of manually selecting one of the first three gears:
1 - 2 - 3.
• Cannot change up a gear when in no load position (foot off accelerator).
• ECU with auto-adaptive "Flash EPROM".
• Downgraded mode operation in the event of a fault.
• Closed loop operation.
• Autodiagnostic and downgraded mode.
• SHIFT LOCK* and KEY LOCK** functions
* Shift lock: impossible to leave position P without having pressed brake beforehand

Hanging on, shuddering etc have all been detected in transmissions that have had incorrect oil in them and this is a common problem here in Australia; overseas, owners tend to read the service manual and not just drop the first oil in that comes to mind.

Again, from ZF Service manual:

V - SPECIFICATIONS - MAINTENANCE
A - INTERVALS - CAPACITIES
XANTIA
Engine ES9J4L3
Transmission capacity 7.7 - 8.3 litres
Draining capacity between 2.7 and 3 litres
Exclusive oil ESSO LT 71141
Draining interval lubricated for life
Top-up interval 60 000 km
Transmission lubrication pressurised
Final drive lubrication oil splash
Weight 88 kg with oil and electronics
Torque capacity 330 mN at 3500 rpm

Personally, I'd start by doing an oil cjhange and seeing if that makes any difference at all particularly if you find in the service records that it had had a transmission oil change and more particularly if the oil used either isn't stated or is different to the above. I understand that Penrite now "may" have a substitute, but be guided by the manufacturers and not by the local greasemonkey on this.
If that makes no difference, then I'd be looking for someone (possibly a Pug dealer) who can upgarde the software in the ECU.
Cit C5s had similar weird things when they came out at first and a trip to get the software sorted usually fixed it.


Alan S