I'm just repairing my instrument cluster to fix a fault in the mileometer (The LCD has failed.) I'm presuming that there is an ECU in the instrument cluster where the vehicle's milage is stored? Is there any other ECU in the vehicle that stores it as well, in effect does the mileage run go with the instrument cluster rather than the vehicle?
Technical Is mileage data only held in the ECU in the instrument cluster?
- Thread starter RedPeril
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Technical Is mileage data only held in the ECU in the instrument cluster?
oldmanhouse
Member
My understanding is that the Body Computer (BCU) is the main unit which stores the mileage, and it communicates it to the Instrument Cluster. I believe the cluster stores the mileage, but I'm not sure if that is just whilst the car is on or if it is saved to memory and "remembered".
Are you swapping just the LCD over, or the whole cluster? If you're doing the whole cluster i'd be interested to know if your car's mileage gets displayed or the mileage of the car it came from (assuming it is from a breaker)
Are you swapping just the LCD over, or the whole cluster? If you're doing the whole cluster i'd be interested to know if your car's mileage gets displayed or the mileage of the car it came from (assuming it is from a breaker)
Thanks for your post oldmanhouse.
I'm at the point of decision now! I think that I have two options:
I'm at the point of decision now! I think that I have two options:
- I could swap the LCD only between the cluster that I have from a dismantler and the cluster in the car. A bit of fiddly work but I think that it is relatively straightforward to do. The risk as I see it is that if the LCD is faulty, I will have probably compromised my warranty by dismantling the cluster. Low risk. I think as it was an eBay seller with a good score and a warranty was offered but you never know. I could plug in the scrappy cluster into my car but being a wary sort of person, I am suspicious that the car might read this and replace the existing genuine mileage, which would get me into all sorts of unwelcome problems to put right (Hense your question,)
- I could put the scrappy cluster into the car as a permanent replacement and spend £50 to get the MES software and adjust up the milrage to be in line with that from my last MoT (The seller told me the mileage on the donor car, which was lower than my cae's mileage.) Again. Mr Cautious steps in again and says "what if you accidentally go way past the desired mileage with the software, then there is no way it will let you go backwards."
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I've just completed a swap of the LCD, as in my option 1 above. All went well, with the most fiddly part being persuading the small plug on the LCD to come out of its socket on the back of the donor cluster, without damaging it. It wasn't too easy to then plug it in to the cluster from my car. My wife's crochet hook proved very useful in pulling it out! A mileage popped up which looks like the car was counting miles during the period the LCD wasn't working. Just got to hope that my "used" replacement LCD keeps working.
The route that I have take was the cheapest. Sending it away to be done gets you a warranty but is significantly more expensive and the car will be out of action whilst the unit is sent away. I couldn't find a UK based supplier for the LCD and import regulations make it non cost effective to buy on the Continent.
Asking a few question (about the Punto) it looks like the storage of mileage data is on the odometer, i.e. within the cluster. The Body Controller Unit apparently does not store mileage data. So if this is correct, when a replacement cluster is put into a vehicle it will only show the mileage record that it carries within it.
Does this make sense to Forum members?
The route that I have take was the cheapest. Sending it away to be done gets you a warranty but is significantly more expensive and the car will be out of action whilst the unit is sent away. I couldn't find a UK based supplier for the LCD and import regulations make it non cost effective to buy on the Continent.
Asking a few question (about the Punto) it looks like the storage of mileage data is on the odometer, i.e. within the cluster. The Body Controller Unit apparently does not store mileage data. So if this is correct, when a replacement cluster is put into a vehicle it will only show the mileage record that it carries within it.
Does this make sense to Forum members?
The Panda Nut
Nutty about Pandas Infected by Panda virus and OPD
On the Panda the mileage seems to be in the speedo AND in the ECU they dont match exactly on any of the ones I have seen either.
Glad you got it sorted.
My understanding is that the mileage is stored in both the dash/dials. The body computer and the engine ECU. So if a car has been clocked its often not changed in all three places and possible for someone with the right kit to discover.
Generally if you replaced the cluster you use software to adjust the mileage on the cluster up to the car's original mileage but if you just fitted a 30k cluster to a car that had done 100k the cluster would read 30k unless you adjusted it. Plug the car into diagnostics and you'll see the true mileage, in fiat's its stored in KM on the computer then badly converted to miles for the dash which is why there can be a slight mismatch sometimes between the gauges and the dash I also believe fiat use a pre-delivery mode in the factory which doesn't increase the mileage on the dash when its being moved around the factory but can result in the body/engine ecu seeing a few extra miles.
As you only replaced the little LCD screen and nothing else, no problems with the mileage and nothing to worry about which is the route I'd have probably taken.
My understanding is that the mileage is stored in both the dash/dials. The body computer and the engine ECU. So if a car has been clocked its often not changed in all three places and possible for someone with the right kit to discover.
Generally if you replaced the cluster you use software to adjust the mileage on the cluster up to the car's original mileage but if you just fitted a 30k cluster to a car that had done 100k the cluster would read 30k unless you adjusted it. Plug the car into diagnostics and you'll see the true mileage, in fiat's its stored in KM on the computer then badly converted to miles for the dash which is why there can be a slight mismatch sometimes between the gauges and the dash I also believe fiat use a pre-delivery mode in the factory which doesn't increase the mileage on the dash when its being moved around the factory but can result in the body/engine ecu seeing a few extra miles.
As you only replaced the little LCD screen and nothing else, no problems with the mileage and nothing to worry about which is the route I'd have probably taken.
