UCH Question

[tomhunt85]

Had the 172 in at Renault because of an issue with the lights. The uch has been found to be faulty and when they tried one from another clio it worked fine. Do I need a uch unit from another 172 or will one off a similar age clio of any spec/engine work?

Thanks in advance.

 

[bmh.01]

Hmm, i'm not 100% sure but iirc you can't just try another cars UCH like that as their coded to the car and part of the immobisiler and once they've been coded they can't be uncoded or swapped about. Having said that the basic functions of it still might work just the car wouldn't start.

You need a new UCH from renault (about £200 iirc) and then an hours labour or someone with a CLiP to code it to the car.

 

[Da]

What Ben said, they're coded afaik and cannot be 'swapped' easily.

 

[tomhunt85]

They're quoting £300 fitted inc diagnostic time so it's about right then.

 

[Dan@SJM]

as above they're coded and lock them selves out if thy're tried somewhere else.

 

[edde]

A new ones £180 or so.

Not worth the hastle looking at a fix just get a new one.

 

[bmh.01]

They're quoting £300 fitted inc diagnostic time so it's about right then.

Yeah i'd say thats about a good ballpark figure.

 

[DrR]

Whats a UCH?

 

[bmh.01]

Whats a UCH?

Look under the passenger side of the dash, the black box with several relays and lots of wires going to it is the UCH. Its a PLC pretty much (basic computer) that controls pretty much all of the auxaillary electrical systems (ie. lights, wipers, climate control). The stalks and switchs are connected to the UCH which is then connected to the devices to give the desired function and allows for things like the auto wipers and lights to the controlled (when it works! lol).

Its also an essential part of the 2nd generation renault immobilser.

In short a very important piece of the car.

 

[edde]

Whats a UCH?

Its the computer which runs all the other computer and runs the electrics in the car.

 

[tomhunt85]

^ and it's broken ^ :-(

 

[DrR]

Ok thanks, i won't kick it in the future then

 

[Da]

Shameless...

UCH


The UCH (Universal Car Harness) is an electronic control module that is fitted to many late model Renaults (early 2000's onwards.) It is responsible for controlling many of the non-engine related functions of the car, such as central locking, electric windows, and even some of the lights (e.g. indicators.)

A brand new UCH is supplied with a blank memory. This must be coded (using the Renault Clip computer) to match the serial number of the ECU and key/card before it will work with the car. The memory can only be written once, so a used UCH cannot be taken from a donor vehicle to be used in another unless the ECU and keyfobs/cards are also transferred.