Ecu Replacement...

[zena ellie]

Hi all i have a 2006 citroen c4 vtr plus 2lt that has stayed throwing up lots of problems with the ecu. To the point where the car will no longer start.had auto electrician check car out and he said the ecu was not working right.. codes were p1621 ecu level 2 module 1,3,5,8,16 and that I would need to replace the ecu

so I am looking for a second hand unit with keys and fuse box and locks alarm. but I do not know how to remove fuse box in car or where the alarm is to remove this. Any help welcome..

[paul.h]

Welcome to the forum.

 

Is your car a petrol or diesel and is the battery in good condition (I would expect the electrician would have checked this) ? Did you try your Citroen dealer before the auto electrician ?

 

There are companies that test and repair ecus rather than having to replace everything and then you would know if it was faulty and I think this would be a better option. BBA reman have often been mentioned in the Car Mechanics magazine as one such company but I have not used them so this is not a recommendation.

 

If you do end up replacing the ecu , then the radio may also need replacing to match the ecu and the fuel injectors may need programming to the ecu. You will be able to use the key blades from your existing keys in the replacement key fobs to save having to change the car locks and ignition lock - just need to push out the small roll pin that holds the blade to the remote fob - or fit the immobiliser chip and electronic circuit board from the replacement fobs in to your existing fobs.

[zena ellie]

It's a 2lt petrol..

since the auto spark had a look the car will not start at all the battery is only a few weeks old.but the car now says it's in anty theft mode. Car turns over but will not start...

[paul.h]

I do not know how far you have got with this but if the ecu is replaced then the bsi fusebox may not need replacing - there is a C3 topic where the bsi was replaced but there is no mention of the ecu so you could ask homerv6 if this was needed http://www.citroen-owners-club.co.uk/citroen/topic/21672-u0028-vehicle-comm-bus-a/ . Hence if the ecu is replaced, then possibly you may only need the key fobs, radio and alarm from the other car but also I would note its VIN and then maybe the fuel injectors programming into the ecu.

 

A search on P1621 (Control Module Long Term Memory Performance/ Immobilizer Code Words Do Not Match) did not come up with anything and seem to be given with other faults but did not seem to prevent a car working. Your description appears to show the car is immobilised so possibly you could try the spare key in case it is an immobiliser fault. I would also contact your Citroen dealer and such as BBA Reman and see what they suggest but a check with a Citroen diagnostic tool (Lexia) may help, unless that has already been done. Was the fault code cleared by the electrician and if so did it come back again ?

 

Sometimes disconnecting/reconnecting a battery can help with odd electrical problems but you say the battery has been replaced so if the problems started before this then it may not help. The following is copied from the C3 Common Problems pinned post:

20. Odd electrical problems caused by wrong battery disconnection procedure.

If you need to disconnect the battery and not do a BSI reset procedure, I have found the following has not given me any problems on a 2004 and 2007 C5 and a 2003 C3:

- remove the ignition key from the car

- open the bonnet

- wait a few minutes for the BSI to shut down

- disconnect the battery negative terminal

 

When reconnecting

- ignition key out of the car

- reconnect the battery

- wait a few minutes

- insert the key in the ignition and wait a minute

- turn the key to the first position and wait a minute

- turn the key so the dash lights come on and wait a minute

- start the engine

- take the windows down and up to reset the anti pinch

- reset the clock (and radio on the C3).

[zena ellie]

Hi I have tried what you have put in the post but it did not work... How do I do a

BSI RESET... When turning the engine over with fuel line disconnected from injectors no fuel is pumped out..I have also tried all 3 keys the mater key says anty theft activated ..

[paul.h]

It sounds as if the immobiliser is preventing the car starting and why the fuel is not being pumped. A search on C4 anti theft suggests it could be a key problem or some other part of the immobiliser that is not being recognised and you are likely to need a Citroen dealer to sort it. The immobiliser consists of the key fob, the aerial transponder which is the plastic bit around the ignition lock and detects the chip in the key fob, the bsi fusebox, the ecu - of these the aerial is only a few pounds but without the diagnostic check it is not possible to easily know what is wrong.

[coastline taxis]

p1621 is telling you that the four digit code on your key is not the same as or not getting to the imobiliser.

 

 

try replacing the transponder ring/ ariel that sits round the ignition lock. there cheap enogh to buy and will activate the anti theft mode. Youl also have economy mode running in the background which when active will disable many features on the car and unless you know about citroen you would think the ecu is gone because nothing is working. once fired up they will all come back.

[zena ellie]

so that means that when I arm/disarm the alarm with the key phob.is not actually working.. lights Flash etc . Doors lock and open but the car will not start..

[paul.h]

The key fob has 2 parts to it. One locks/unlocks the doors and the alarm and the other is a chip for the immobiliser which when the key is in the ignition lock is detected by the transponder aerial around the lock so the immobiliser can be deactivated to allow the car to start.

 

The transponder aerial part no. may be 6160C1 or 6160F0 and to check you need to use your VIN at the Citroen dealer. Costs about £5 new from Citroen (do not buy a used one from ebay since they seem to be asking about £25). Fitting time is about 20 minutes so will not be difficult.

[zena ellie]

Ok that's it going to replace ecu transponder lock etc fuse box any one tell me how to get plastics off strearing wheel so I can replace ignition lock and Transponder

[paul.h]

No need to change the lock, use your old key blades.

 

According to the Haynes manual the steering column shrouds are held by 2 screws in the lower shroud - remove these and the top and lower shrouds will lift off. It may help if the steering wheel is pulled out and raised up to give more room. The transponder aerial should just unclip from the ignition lock and slide off after undoing its electrical connector. Before going any further I would try your new aerial in case this is the fault and hopefully no need to replace the ecu, etc.

[zena ellie]

I have orderd a transponder.but I am bidding on a full system .fuse box . BSI

Ecu. Locks barrel . key ext.but only the Master key

 

Looking at the plastics I can only see what look like small nuts not screws and I cannot get anything to fit them

[paul.h]

The 2 screws are located at the underneath of the lower shroud, close to the steering wheel end. The Haynes manual shows a screwdriver being used to undo them so could be a cross head or torx head screw.

 

Citroen's parts diagrams show 8 different ecus, 14 bsi fuse boxes and 6 engine fuse boxes, so you need to be careful that you get the right ones for your car or you may find some things on your car will not work. You can see the parts diagrams as a free service by registering as another professional and a member of the Citroen Owners Club on the service.citroen site. Then use your car VIN (VIS) in the top left of the parts diagrams to see the parts for your car. http://service.citroen.com/do/changerParametres Note that Citroen part numbers are not the same as those on stickers on parts - these are manufacturer part numbers.

The ecu can be found under Mechanical, Air and Fuel Supply, Inj Calculator Sensor.

The BSI can be found under Electric Unit, General Points, Units/connector boards/kits, Electronic box MUX.

The engine fusebox can be found under Electric Unit, General Points, Units/connector boards, Checking stand and fusebox.

 

If you are only getting the master key (presume you mean the remote key fob), then you will only have one key with the immobiliser chip in it that will start the car and to get a spare you would need to go to Citroen so allow for this in your costs. Also you will need the VIN from the donor car and the key code from it - otherwise Citroen may not be able to provide a spare key with the immobiliser chip but there may be companies that can read the code from the master key to be able to provide one.

 

However, I can not help feeling you will be going to a lot of bother and expense when if the new transponder aerial does not work, you would be better going to your Citroen dealer for a diagnostic check to see what is wrong with the car.

[zena ellie]

The faults started to come up about 2 days after my car was broken into. Using a remote scanner.which searches for your alarm signal when it finds it you can open the door . But it dose not turn alarm ect off

it just unlocks the doors.but it cause a fault in the ecu . Have sent bbs two emails to see if they can fix ecu but I have not had a reply

[zena ellie]

Have tried transponder but still not starting.and I have bought a new battery but still nothing is there a separate ecu unit for the alarm off so dose anyone now where it is

[paul.h]

Please add replies to these posts to this topic http://www.citroen-owners-club.co.uk/citroen/topic/21921-ecu-replacement/?do=findComment&comment=80535