Hi All,

I'm having problems with my Australian 2003 2.1 litre "poverty pack" sedan. It's giving me the P1603 code and I have a transmission warning light on as well as a HO2S warning and a knock sensor fault. The car is a sympathy job,
was on the side of the road for 12 months and I couldn't bear seeing it rot away.
The knock sensor and H02S codes I'll get to later, but the TCM worries me. I've changed the battery cables (as directed in here ) and have checked for anything else suggested in the forums.
It seems to be somewhat intermittent, I clear the codes and go for a quick drive and it's ok but when
I start it again I get the code. I did find some white fluff corrosion on the current TCM but it looked good after cleaning, but I'm still thinking that it may be the unit. I've found a replacement on ebay,
but the part number is 2X43-72401-JB whereas mine is 2X43-72401-JA.
Would these units be interchangeable and if so are they plug and go or do I need to get some form of recoding done to the car to get it to work?
Thanks in advance for your advise.

 

Hi,
I am not sure on the TCM parts coding. I believe from other postings about TCMs that you need to stay exact or very close to your original coding to avoid having to get it re-programmed for the car.
Thermo might have the answer to this particular question within his treasure trove of information.
I know there are two types of TCM, a 16 Bit version that has a single large 54 pin connector and a 32Bit version that has two 24 pin connectors.
I am also aware that within those two distinct product versions there are spawns during the production resulting in the suffix changing.

What I am intrigued about in your description is the re-occurrence of the fault once cleared when you start the car again.
Is your TCM error light coming up immediately upon ignition prestart (position 2 of key), or engine starting (and simply standing and idling), or only once it has started and you try to move the selector out of park into a gear selection, or when you actually start moving?
Understanding at what point of operation the error light returns may help eliminate some perpherals.

Also, unsure if you have physically opened the TCM to look for signs of internal corrosion, or was the corrosion you described found on the external connector pins of the TCM.
If you have just cleaned the exterior pins and socket, then you probably need to open the TCM to check for what may have seeped in as well.
Moisture reaching the TCM often comes from the heater assembly due to incorrectly fitted cabin air intake filter or blocked drainage and debris in the air intake area.

Also what did you clean the corrosion off with?
IPA (Isopropyl Alcohol) and a small clean paint brush or an old tooth brush are good for scrubbing off contaminants on PCB and connectors depending on bristle length needed.
If you have any remaining residue due to the first cleaning product purity, then you might want to repeat the cleaning process with something more pure just in case.

 

Hi Mr H2o2stream,
Thanks for responding. Only minutes ago I did find a thread and an answer from Mr Thermo who said as you did, part numbers are the same but the suffix JA and JB refer to software versions. My current TCM has the one 54pin (not that I counted them ) connector. The light comes on again during the key turn on, before the engine start so I'm reasonably sure at position 2. I did open the box, white fluff corrosion was present on the main ic pins on one side. I used Isopropyl as you suggested and a delicate cleaning brush (same sort as a toothbrush but a bit softer). All the corrosion came off but there were several discoloured pins and lands. There was also some corrosion on the rear of the board but that came off quickly. I had a good look at the plug and pins and could not see any obvious discolouration or growth. I do think that I have the cabin filter kit mod done, there is a piece on plastic attached to the left hand side on the cabin filter housing which doesn't look as though it was part of the original design. I haven't seen any water ingress to the cabin yet but I haven't driven it much as I'm working to revive it before I can get it registered for the road.

 

I'll not dive into the murky waters of compatability for the very good reason that I don't know but can offer this extract from JEPC (Jaguar Electronic Parts Catalogue) showing the many changes in TCM part numbers for the 2.0:






Disregarding the superseded ones (rotating arrows symbol), it looks like there's three different TCM's depending on VIN.

Graham

 

I did a google search for your exact part and got =
1. Britain = €85 Used = out of stock
2. Netherlands = New €302.50 = in stock
3. Britain = €42 Used = in stock
4. Ukraine = 869 rph Used = in stock
5. Poland = 79.99 zloty Used = in stock

 

Hi mderrett,
Further to my first reply, the 2.1 model was the more frequent engine option here in NZ as well.
FYI, the predominant local public online auction trading site for most everything here is NZ is www.trademe.co.nz if you were trying to find things across the ditch.
In saying that, I don't often see individual car parts being listed as it is a small market here, but the wreckers generally list the vehicle being wrecked by make and model and then offer up a token auction for one bolt for $1, just so you can find their listing and then ask questions via the auction about any specific parts you might want.

It sounds like the corrosion you found may have damaged some components. The solder does get eaten by water, and the presence of voltage and current creates an electrolysis action that promotes the creation of that corrosion.
IC legs can off, copper tracks can rot through and surface mounted resistors and capacitors can have their ends eaten away.

If the error is coming up as soon as you turn on the ignition, then it is likely a comms problem between the TCM and ECU and instrument cluster.
Sounds logical to conclude it is the TCM adn unless you are going to a compenent level electronic repair, a replacement module is likely the best 'plug and play' option for you.

Would you like me to see if I can locate a TCM of the same part number/suffix here in New Zealand?
If you want me to look for you, I can make some inquiries and let you know what I find and how much they are asking for it.
Depending on where the seller is, if locally I could pick it up or get it sent to me and then I could send it across to you.

 

Hi mderrett,

Hope you are well.
How have you got on?
Do you need some additional help with this at present, or are you on pause at the moment due to CoVID lockdown?

Sorry to be seeing that NSW has been plunged into general lockdown and Sydney is looking to be the hardest hit area there.
Your State and city has carried the bulk of the quarantine burden for tens of thousands of returning Australians - and has done it darn well.
Bloody shame as it seems an idiot shuttle driver has screwed it up for you by defying direct medical orders.

 

HI,

Thanks to all for your replies. I went ahead and purchased the JB unit based on Mr Turbo's information, it would only be one revision up from my original and as there was a TSB that talked about reflashing the TCM I figured it was probably a safe bet.
I opened it when it arrived and it's in absolutely pristine condition, not a mark on it. I've finished my bit on the car (interior, new radio, rear vision camera and sensors, sound proofing and so on ) and it's now in my trusty mechanic's shop getting the air conditioning fixed and a good check over before registering it for the road. Being an old Queensland car being transferred to NSW, never say governments don't miss an opportunity to rip a few more dollars off you.
Mr H2O2steam, thank you for the kind offer. If it all goes to hell in a handbag, I may take you up, but I'll wait and see how the JB unit goes. I can always sell it on if it doesn't work.
As for covid, I would be one of the lucky ones, I'm up on the north side of Sydney quite a way from the epicentre, I actually walk to work which is still open for us (I work in the disability support business so I'm classed as an essential worker) but I'm free to work from home if I want (and I do). I must be one of the weird ones, I actually looked at the evidence for the AstraZeneca vaccine and didn't fall for the media bull, I've had my first shot and am just waiting for the second so all is good here. Hardware stores and takeaway still open, I can live with that.
Mind you, no one in Sydney will admit now to driving a limo.....

 

Hi all,

Happy to report that it's back and running perfectly with the 2X43-72401-JB part number unit fitted in place of the original 2X43-72401-JA. New air con, new rear O2 sensors and other minor bits. Just waiting for rego (and covid lockdown ) to end.
Thanks again to all for your assistance.