2002 (Mk1) C3 Abs Fault

[alanhatter]

I have a 2002 C3 1.4i petrol. It has covered 120,000 since we bought it new. It has just failed its MOT due to a seized abs pump (the dashboard warning light won't extinguish even after the ecu has been reset). So there are 3 options open to me. 

 

1: Get Citroen to supply/fit and code a new pump. 

2: Scrap the car. 

3: Locate a secondhand unit and have my garage fit it.

 

1 is never going to happen as the cost is greater than the value of the car. 2, I would hope would not be the case as it would be a terrible waste. So that leaves 3.

 

So the question is this. If the pump and ecu are specifically coded to my vehicles chassis (so say Citroen), I know its possible to obtain a secondhand unit off of Ebay lets say. Therefore can my garage separate that pump from its own ecu, do the same with mine and refit the replacement pump to my ecu and then reinstall it into the car, thus resolving the problem and avoiding a 1400 bill from Citroen or indeed scapping the car?

 

It appears now that we are not throwing cars away because they rust to death anymore, but rather that their electronics fail them!

 

Many thanks

 

alanhatter

 

[paul.h]

Welcome to the forum.

 

Citroen's procedures show the abs ecu can be unbolted from the hydraulic block, so it would appear you can re-use your old ecu on a replacement pump - assuming your ecu is not faulty. The battery should be disconnected first, then undo the electrical connector, the ecu bolts and then it should remove. On the mk60 pump (up to RPO 9423) there are 2 bolts (5-6 Nm) through the top of the pump to undo to release the 47 pin ecu  and on the mk70 pump (from RPO 9424) there are 3 bolts (2-3 Nm) under the 26 pin ecu to undo. Refitting is a reversal but it says to apply grease to the electrical terminals using Total N4128 and to use new bolts. No coding is needed, just fault codes checking/deleting, unless a replacement ecu is used.

 

A replacement pump will need to be bled of air and this needs it to be connected to a Lexia type diagnostic equipment, so if your garage does not have this or something similar that can be used, it will need to go to a dealer.

 

To get the right replacement pump, you need to use your vin in the parts diagrams since there are about 6 different ones but this could be so the ecu is the right one since some cars have esp - but it may just be a case of getting one with the same no of pins on the ecu since apart from mk60 or 70 block, the hydraulic blocks may be the same but the ecu being a bit different. If it is your ecu that is at fault, then ask Citroen if a used one can be coded to your car, if not Citroen sell the ecu separate to the pump.

 

Under the C3 technical section there is a list of common problems that includes a procedure for disconnecting/reconnecting the battery to avoid electrical problems.

[alanhatter]

Thankyou for this. However I have 2 other questions? Is changing the pump over, the same as changing the ECU, or can the ECU be swapped more easily?

 

And secondly, why not just disconnect the faulty abs, have the dashboard light extinguished and just rely on a set of brakes (h&s accepted). After all, the best car we ever owned was a 1990 Citroen 2cv and that didn't have abs!

[paul.h]

Without the abs working the car will not pass the MOT test and may make the insurance invalid, but the brakes should work as though the car did not have abs installed. If your car has esp, then this also would not work if the abs is faulty.

 

From what I read, the abs ecu can be replaced on the pump with the pump still in place on the car - but the new ecu will need to be coded to the car. The pump part if replaced without changing the ecu for a different one, would not need the ecu to be coded to the car but would still need the pump and brakes to be bled of air and this needs the valves in the pump to be opened and probably the pump to run - which require the diagnostic equipment. If you can get a pump that is full of brake fluid without any air in, and air does not get in to the brake pipes while disconnected, then there may be a possibility the brakes can be bled without needing the diagnostic equipment. If at all unsure though, I would get the work done at a dealer or garage with the correct equipment - or possibly fit the parts yourself and get the dealer to bleed the brakes. If you used a garage without the equipment and then had to use a dealer to bleed the brakes/code a new ecu, then I suspect this would cost more than going to only the dealer.

 

In your place, I would ask the dealer to quote for fitting a used pump with its used ecu (unless I thought the ecu was ok) supplied by myself. On ebay used pumps are about £40. A new pump from Citroen, depending on your vin, is about £600 already configured, plus 1 or 2 hours to fit. A new ecu configured is about £400 but is included with a new pump but the pump is not listed without the ecu.

[alanhatter]

Citroen quoted £937 + vat just for the pump+ECU. Then there is the labour charge for fitting/recoding hence you might as well scrap the car!

 

So, now I know which way to go, I'll get a second hand unit and get my garage to sort it. I will advise you how it all turns out. Alanhatter.

[paul.h]

The prices I used were from these people but I did not know which exact part no to use but the second hand option is going to make the repair worth doing. http://www.citroencarparts.net/ - to get a price you enter the part no. in the top left search box. The part no. you get from the service.citroen site , register/join as another professional, member of the Citroen Owners Club and the parts diagrams are a free service http://service.citroen.com/do/changerParametres

[alanhatter]

Fantastic. I will let you know once the job is done.