C5 Automatic Gearbox Flare/neutral Problem

[Pat Clancy]

I have a 2006 Citroen C5 diesel automatic that has done 75,000 miles, which has an AISIN AM6 automatic gearbox.  The gears go into neutral between all upward gear changes.  If the throttle is backed off, then it will change gear ok, or if the car is driven very gently, then it will avoid the problem.  The more power being put through the gearbox then the worse the problem gets.  I have been told by 2 independent automatic gearbox specialists that this is a common problem with this gearbox and the valve body will need replacing, at a cost of around £1,500.  (This gearbox seems to be fitted to several makes of car, not just Citroen).  The local Citroen garage investigated the problem for 2 hours, but could not find the fault and suggested a transmission fluid change, but they weren’t too hopeful that this would fix the problem.  I have looked at a web site for a company called Sonnax who are gearbox specialist in the USA and they strongly recommend using a scan tool or pressure gauge for valve body diagnosis.  This is a link to their article 

 

http://www.sonnax.com/articles/137-AW-6-Speeds-Valve-Body-Diagnosis

 

The closest Citroen garage I can find with scan equipment is in Coventry, (I live in Ipswich).  So my questions are….

 

1) Has anyone else had this problem or am I just unlucky?  (I have found some problems on the internet for Citroen C6's).

 

2) Does anyone know of a garage that can do diagnostics while the car is being driven, (i.e. has a scan tool), that is closer to Ipswich than Coventry?

 

 

                                    Thanks,

 

 

 

[paul.h]

Welcome to the forum.

 

cfryve was the forum expert on auto gearbox problems but he has not been on the site for over a year. A search using cfryve comes up with a few posts such as this one http://www.citroen-owners-club.co.uk/citroen/topic/9382-gearbox-valve-control-unit/?hl=cfryve

 

I would think any Citroen garage or Citroen specialist would have the diagnostic equipment - should be the Lexia for Citroens. Copies of this are also available on-line to install on a lap top for about £100 and some members have these. This post contains members who are able to help others with diagnostics but I do not know if any are near enough to you http://www.citroen-owners-club.co.uk/citroen/topic/20345-diagnostic-help/

 

The Citroen parts diagrams can be seen as a free service if you register as another professional and a member of the Citroen Owners Club on the service.citroen site. Use your VIN (VIS) in the top left to find your car http://service.citroen.com/do/changerParametres

 

 

 

I have moved your post in to a subforum since ones outside of one do not show after a few days and are then difficult to find.