FL1 TD4 5 Door 2001 CCU

Central locking, all windows, rear door latch and all other numerous CCU associated functions stopped working about a week ago ( I only have a key as the remote fob stopped working some time ago even after fitting with a new battery ). Ignition still worked ok and all other non CCU functions seemed to work, in essence car continued to drive fine but for the seemingly CCU related issues. After reading quite a lot here ( my thanks to everybody for their input, much appreciated ) about the CCU function and location I checked the fuses in the cabin fusebox and they all seem ok. I got a secondhand CCU from ebay (YWC000030 / YWC500211E) that was listed as being compatible with my TD4 2001 AWD I L314. My Haynes manual made it sound easy to replace the existing CCU but for a 72 year old laying upside down half in the footwell just to locate and remove the three bolts holding the fusebox mounting plate was a little challenging let alone disconnecting insitu the three plugs on the side of the CCU and finding and pressing the release tags in order to separate/unplug the CCU from the fusebox. So I was really pleased with myself when I finally managed to fit the replacement CCU and thought I won't refit the three mounting plate bolts just in case I have to put the old one back in again. Then it all goes pear shaped - after reconnecting the battery negative lead I put the ignition key in and turned to start the engine and heh presto no ignition, all display warning lights came on, horn going like it's trying to wake the dead. Is this indicating a) the ebay CCU is malfunctioning or it's the wrong part supplied b) I haven't refitted the two, smaller but seemingly the same, CCU side plugs in their right sockets or c) does the whole CCU/Fusebox assembly rely on the mounting fixing bolts to provide an earth connection. Any help would be much appreciated as I've had my TD4 since 2004 and it's been very reliable with only 125k on the clock so far.

Have you compared part numbers of the old and replacement CCU?
I can't remember exactly, but I'm sure the CCU has something to do with the immobiliser and alarm system, presumably it'll pass the key recognition code to the alarm module, and send the vehicle unlocked command to the alarm too. Normally when the CCU is swapped, it's best to swap the alarm module and ECM at the same time. There are sellers on ebay that sell kits of everything needed, often including a fob or two in the kit.
Using the door key all the time isn't ideal, as the lock is designed for emergency use, so they wear and fail eventually.

Nodge68 said:

Have you compared part numbers of the old and replacement CCU?
I can't remember exactly, but I'm sure the CCU has something to do with the immobiliser and alarm system, presumably it'll pass the key recognition code to the alarm module, and send the vehicle unlocked command to the alarm too. Normally when the CCU is swapped, it's best to swap the alarm module and ECM at the same time. There are sellers on ebay that sell kits of everything needed, often including a fob or two in the kit.
Using the door key all the time isn't ideal, as the lock is designed for emergency use, so they wear and fail eventually.

Click to expand...

Thanks very much for responding so quickly, I think the numbers were the same when I checked but I'll take it out again to be sure as it's no good as it is anyway as I can't even drive the car now. You're right, I just checked the Haynes manual and it does say the CCU controls the immobiliser and the alarm system among a host of other features. Perhaps I misunderstood from other threads previously, from what I read I thought it was just a 'plug and play' swap over as long as it was the right replacement CCU, ( I wonder if it's a different CCU for a 3 door model of that year and is that what I've just fitted on my 5 door TD4 and causing the electronics mayhem ?) I didn't read anything about the need to swap the alarm module and the ECM, if that's the case I need to get a better understanding of what's actually involved before going down the road of buying more perhaps wrong or insufficient parts. Thanks for your view on using just the key as I don't have a fob, I've avoided buying another fob for over 18 months as I was told they cost over £120 each (plus programming ?) Do you know how the CCU gets to recognise a key recognition code if the key itself doesn't have any electronic parts in it as far as I can see. I've now had a quick look at the kits on ebay you refer to that come with fobs but some are saying programming required which I don't have the capability to deal with, my 'speciality' before I retired was Building Services installation and contract management

I wasn't aware of the CCU having any immobiliser function. I have changed a CCU over and only thing that needed changing was to reprogram the fobs.

I would think with the symptoms you give, that either the new CCU is faulty or there is another wiring fault which made the original CCU fail. The 5 door and 3 door are different but only because of the roof switch which drops rear window on a 3 door when you take the roof off.

The immobiliser is almost impossible to remove without taking dash out.

andyfreelandy said:

I wasn't aware of the CCU having any immobiliser function. I have changed a CCU over and only thing that needed changing was to reprogram the fobs.

I would think with the symptoms you give, that either the new CCU is faulty or there is another wiring fault which made the original CCU fail. The 5 door and 3 door are different but only because of the roof switch which drops rear window on a 3 door when you take the roof off.

Click to expand...

Hi and thanks for responding. Just reread the Haynes Manual for 1997 to 2002 Chapter 12 page 19 and it states - Depending on the market the vehicle was intended for, the CCU is responsible for controlling the following functions, one of which listed is Anti-theft alarm system - the CCU is responsible for controlling the central door locking and alarm/immobilisation functions. Haynes lists 18 separate functions in total. If I've understood correctly the CCU's for the 3 and 5 door variants are different then, I guess I need to recheck the part numbers on both the original and replacement CCU to make sure I've got a 5 door one. If they are the same then I think I'll need to hand my car over to my local auto guy, who has proven very capable over the last 8 years, for interrogation and fix if I can't sort it myself.

andyfreelandy said:

The immobiliser is almost impossible to remove without taking dash out.

Click to expand...

Noted, thanks. I thought I was going to have to cut the driver's side glove box out when trying to swap over the CCU's but managed to get my hands in and 'remove and replace' almost in situ after removing the two relays to the side of the fuses and the three CCU wiring plugs. I think I also need to check the wiring diagrams in the Haynes manual to make sure I've put the two smaller CCU plugs in the right way round. 31/08/23 Update - plugs were located correctly and fully inserted.

Might be worth trying to provide an earth to the CCU metalwork before you pass it on. I think if you had a 3 door CCU it would only affect the rear window. As said, there was no coding or changes required when I swapped a CCU. Just the fobs to recode to the CCU. If the CCU controls immob functions then they are passive and don't affect coding.

Fobs can be bought secondhand for 10 or 15 quid. Reprogramming is simple with the kit, which I have.

RAVE Manual lists the CCU as this:
Central Control Unit (CCU)
The CCU is plugged into the back of the passenger compartment fusebox below the fascia. Two connectors provide
the interface between the CCU and the passenger compartment fusebox and three connectors provide the interface
between the main harness and the CCU. The CCU is responsible for controlling the following functions:
l Transit mode.
l Anti theft alarm.
l Windscreen wipers.
l Courtesy lamp delay.
l Door open warning lamp.
l Key in alarm.
l Rear fog guard lamps.
l Lights on alarm.
l Seat belt warning.
l Handbrake warning.
l Rear screen wiper.
l Tail door window.
l Heated rear window.
l Heated windscreen.
l Tail door latch.
l Window lift.
l Seat heating.
l Daytime running lamps.

The vehicle locking and alarm system is controlled by the central control unit (27VT) located on the back of the
passenger compartment fusebox below the fascia.
The immobilisation system (EWS-3D) is essentially a stand alone system with its own controlling ECU located
centrally behind the fascia.

Immobilisation System - General
The function of the immobilisation system is to prevent unauthorised starting of the vehicle. The ECU operates in a
secure interface which cannot be by-passed or copied. Re-mobilisation is achieved through a transponder in the
vehicle key which is energised by a transponder coil surrounding the ignition switch when the ignition is turned to 'AUX'
position I. When energised the transponder data is read by the immobilisation ECU which will confirm the validity of
the start request.

So it looks like the chip held in the key connects through the transponder coil around the key and then direct to the immob ECU.

Good to know, thanks. How much would reprogramming cost ?

andyfreelandy said:

Might be worth trying to provide an earth to the CCU metalwork before you pass it on. I think if you had a 3 door CCU it would only affect the rear window. As said, there was no coding or changes required when I swapped a CCU. Just the fobs to recode to the CCU. If the CCU controls immob functions then they are passive and don't affect coding.

Click to expand...

Sorry if this sounds daft as I'm far from being an electrician but much much better with plumbing and heating. Do you think putting the three fusebox mounting plate bolts back in will provide a required earth to the plugged-in CCU (and fusebox ?) According to Haynes these three bolts connect the mounting plate to the steering column support bracket and the vehicle body)

It might need the bolts to provide ground. If it is missing a ground then it won't work properly. I can't recall if the bolts are electrical ground or just mounting bolts. You can wire the metal leg on the CCU to the car body as a temporary test.

Programming takes 10 mins. But would need car and all fobs.

andyfreelandy said:

So it looks like the chip held in the key connects through the transponder coil around the key and then direct to the immob ECU.

Click to expand...

That suggests to me then that the key wouldn't need to 'recognised' by the CCU and should not be causing the electrical mayhem that ensued after I did the CCU swap. Could it simply be the bolts need to go in to provide the required earth and/or is it that I've put the two small CCU wiring plugs back in the wrong sockets on the side of the CCU.

andyfreelandy said:

RAVE Manual lists the CCU as this:
Central Control Unit (CCU)
The CCU is plugged into the back of the passenger compartment fusebox below the fascia. Two connectors provide
the interface between the CCU and the passenger compartment fusebox and three connectors provide the interface
between the main harness and the CCU. The CCU is responsible for controlling the following functions:
l Transit mode.
l Anti theft alarm.
l Windscreen wipers.
l Courtesy lamp delay.
l Door open warning lamp.
l Key in alarm.
l Rear fog guard lamps.
l Lights on alarm.
l Seat belt warning.
l Handbrake warning.
l Rear screen wiper.
l Tail door window.
l Heated rear window.
l Heated windscreen.
l Tail door latch.
l Window lift.
l Seat heating.
l Daytime running lamps.

The vehicle locking and alarm system is controlled by the central control unit (27VT) located on the back of the
passenger compartment fusebox below the fascia.
The immobilisation system (EWS-3D) is essentially a stand alone system with its own controlling ECU located
centrally behind the fascia.

Immobilisation System - General
The function of the immobilisation system is to prevent unauthorised starting of the vehicle. The ECU operates in a
secure interface which cannot be by-passed or copied. Re-mobilisation is achieved through a transponder in the
vehicle key which is energised by a transponder coil surrounding the ignition switch when the ignition is turned to 'AUX'
position I. When energised the transponder data is read by the immobilisation ECU which will confirm the validity of
the start request.

So it looks like the chip held in the key connects through the transponder coil around the key and then direct to the immob ECU.

Click to expand...

Thanks for this, the Rave list agrees with the Haynes one by the look of it and good to know how the immobilisation System works, appreciated. I also need to check with LR online or a reputable site to confirm the correct CCU part number that I need to use if I find the replacement isn't correct for my TD4 2001 Diesel 5 Door manual transmission.

andyfreelandy said:

It might need the bolts to provide ground. If it is missing a ground then it won't work properly. I can't recall if the bolts are electrical ground or just mounting bolts. You can wire the metal leg on the CCU to the car body as a temporary test.

Click to expand...

Thanks very much, will try tomorrow morning if it's not pouring with rain. Hopefully it's just the ground needed, fingers crossed then.

IIRC Think the CCU does control immobilisation on early cars, but MY01 cars have the separate immobilisation module.

I may have made that up.

andyfreelandy said:

Programming takes 10 mins. But would need car and all fobs.

Click to expand...

Thanks

GrumpyGel said:

IIRC Think the CCU does control immobilisation on early cars, but MY01 cars have the separate immobilisation module.

I may have made that up.

Click to expand...

Thanks for this, is there a way that I'm able to confirm if I'm an 'early' or not ?

Nodge68 said:

Have you compared part numbers of the old and replacement CCU?
I can't remember exactly, but I'm sure the CCU has something to do with the immobiliser and alarm system, presumably it'll pass the key recognition code to the alarm module, and send the vehicle unlocked command to the alarm too. Normally when the CCU is swapped, it's best to swap the alarm module and ECM at the same time. There are sellers on ebay that sell kits of everything needed, often including a fob or two in the kit.
Using the door key all the time isn't ideal, as the lock is designed for emergency use, so they wear and fail eventually.

Click to expand...

Only just started to work on it again and heavy rain has arrived. I've attached an image of the original CCU showing part numbers etc, it shows as being YWC000031 would that be an issue if the replacement I fitted is YWC000030 ? I'll take the replacement out later and check the numbers on that and update here to suit. 31/08/23 - Seems like the YWC000030 needed to be replaced, see bulletin info below.

31/08/23 Update (I've copied this elsewhere in this thread) Fitted all the bolts and made no difference when turning the key, symptoms presenting same as my original post. I'm not sure whether I have read in this forum or someone told me recently but it now seems that my original keys have a cell inside them that communicates with the drivers door lock sensor and that communicates with the CCU/ECU ? the keys need to be synchronised/programmed to the replacement CCU/ECU ? to enable recognition of my keys and then maybe all the symptoms disappear hopefully. I've been searching for quite a few hours but can't seem to find any 'workarounds' so am I at a stage where I have to pass over to my auto engineer. FYI if anyone is interested a TD4 CCU 2001 bulletin I just found online - http://www.myfreelander.co.uk/Body/bodyprobs27.htm
sorry about the ads down the sides they seem to come with it.