Help! Part number / price required

**chrisdownes** · 8th July 2008, 15:40

I have a problem in that my number plate lights and high level brake light are not working....

I have done all the bulb checks etc and they are all ok.
On the numberplate lights, I am getting 9v to both lights and no current, which is why they not lighting up the bulbs.

Looking through the Haynes manual both these systems are controlled by the Rear Electronic Control Unit. With this in mind does anyone know a part number / price for this unit as I believe it to be where my fault lies

Any help much appreciated.

**chrisdownes** · 8th July 2008, 16:32

Possibly sorted via MegaVaux.....

They have one in stock out of a car breaking for £50

Ordered it, should be here Thurs so fingers crossed I will have working lights again!

**Gsi3.2** · 8th July 2008, 16:42

lets hope it won't need programming as the REC is part of the canbus net..

**chrisdownes** · 8th July 2008, 16:48

Oh your kiddin me

Hopefully it wont need programming then, else I will not be happy!

**Duncan** · 8th July 2008, 17:23

Originally Posted by chrisdownes

I have a problem in that my number plate lights and high level brake light are not working....

I have done all the bulb checks etc and they are all ok.
On the numberplate lights, I am getting 9v to both lights and no current, which is why they not lighting up the bulbs.

Huh? How can you be getting a voltage but no current? How are you taking your measurements?

Are you sure it's not elsewhere the problem lies? - before you off changing the REC. It's very unusual for them to go, can't recall anyone having had one need replacing, and you then face the problem of maybe needing it re-programmed into the car.

**chrisdownes** · 10th July 2008, 14:58

I have put on the replacement REC today, and now have working number plate lights and voltage to my high level brake light (I just need to fit the new light now).

I now cant open my boot though! Im assuming the REC I have fitted has come off a car that didnt have the electronic boot opening thingymajig.

How can I get it working, is there a key / button sequence I need to go through?

Grrrrrr........ cars......... how annoying!!

**Ben Humphrys** · 28th October 2008, 19:45

I had exactly the same problem as Chris, 9.5V which vanishes when the bulb is connected. 55 Diesel version.

Yes, it's the rear ECU. Thanks very much Chris, this thread gave me confidence to look at the job myself. There are a few additional bits of information which may help others:

You have to take the lining out of the hatch compartment passenger side, to get to the box. Don't worry it's easy- one plastic clip, remove the black plastic bit at the back, pull back the rubber seal then the liner comes out.

The retail price from Lookers for the box is £284 plus VAT.

I had a quote for £94 and a quote for £55, I went for the £55 one and although it looked the same as mine it had several differences in fuse, relay & plug configuration so I guessed it wouldn't work- take care you get the exact same model!

My background is electronics so I decided to trace the circuit back through into the box, and got to a chip called a VND830SP, dual high level driver. Data is available on this link You can get these from RS components for a couple of quid, but the RS web site said none in stock until January 09.

So I decided to attempt a risky transplant, desoldered the broken one and resoldered one from the scrap box. Can I just say that this isn't easy because the chip is lacquered over, is a surface mount device and has a heat sink tab too.

But it worked.

I fell for the trick of letting the hatch drop shut, so had to crawl over the back seat to re-install the box. What on earth goes through these people's neanderthal minds that makes the boot access require a working computer in the boot and CAN bus link to drive a servo lock open????

I disconnected the battery when re-installing the box, didn't want to risk scooping connections and blowing the card again.

I have a couple of photos I have tried to upload.

Good luck!

**meccano** · 27th January 2009, 15:18

EXCELLENT post on trouble-shooting and replacement of the electronic relays on the rear ECU panel and your advice that this task is only for those with the necessary skills! I would add that simple d.c. voltmeter tests are inadequate to prove some of the relay outputs.

Re the problem of accidentally closing the hatch when the electronics are disabled or the ECU removed (and not being able to reopen it), there is a hatch lock release (see below) behind the rubber bung above the lower edge of the hatch. Jiggling this with a screwdriver (about 11 mm blade) will release the opening spring in the lock. Access via passenger compartment with torch!

My hatch lock has occasionally got itself into a fault condition when the hatch lid is open: lock closed and does not respond to unlock button or remote, with hatch open warning in display, possibly due to an intermittent fault on the lock-motor switches.
In this state the hatch cannot be closed and the motor does not rotate when the hatch button pressed. Again a quick jiggle with a screwdriver is all that is required to release the lock.