14CUX ECU Variants

[markgreen]

OK - So I fried my ECU.

Now I need a new one and the question is: Can I buy any 2nd hand 14CUX and put in my EPROM (which is hopefully OK)?

Car: 1996 Griffith 5.0 HC
ECU: Land Rover AMR2175 14CUX 80405 A Date COde 3496 ( Hand writing ??1965?? 5.0 Neil )

If my EPROM is fried too will a Range Rover one drive the car while I wait for a new one?



So now here's the story:
Car wouldn't start, traced no power to fuel pump. Tested pump relay out of car - not working.
Went to buy new relay and got sold the wrong one. The diode in my replacement is parallel to the coil not in series.
Smoke comming from ECU :-(
So I guess the diode in the relay has allowed WAY TOO MUCH curent and burned out the power circuit on the board (not opened it yet to look.)

[blitzracing]

Any 14CUX ECU from around 1992-3 onwards will do, they are all plug compatable. The cases are different depending on its origional mounting, but you can just swap the PCB across into your case. The pre ECU 1992 wont run the TVR catalysts fuel map correctly if you swap the chip. You could run the Range Rover map as a get you home, but some of these maps run very lean at higher RPM

[markgreen]

Winner - What would I expect to pay for a 2nd hand....

I need to pick something up while I'm home this weekend - the car is in Ireland at the moment.

[DarkMatter]

You could probably pick up a 14CUX for upwards of £50 but note that some (Land Rover ones) have the EPROM chip soldered in - this will have to be de-soldered and replaced with a socket into which the TVR EPROM is plugged. It's quite a delicate job desoldering the old EPROM and soldering in the socket because the PCB tracks are very fine and can be easily damaged. It would be easier to source a TVR 14CUX which should already have a socketed EPROM.

[blitzracing]

As the man says above, but I think sockets are fitted from around 1993 onwards as standard. If you do get one without a socket you MUST cut the old chip out by cutting all the legs, and then having removed the chip body, then carefully remove each chip leg one by one with a solder sucker and soldering iron. To make matters worse its all covered in laquer, but it comes off with some white spirit. Its not impossible, but needs a steady hand. You can get sockets from Maplin for about £1. Price wise I payed around £25 for ECU's (2 off) but I think I got lucky on Ebay.

Edited by blitzracing on Friday 2nd July 21:00

[dnb]

I have done a fair amount of PCB rework in previous jobs and as part of a hobby. If you're careful there is no reason why you can't remove a socket from an older style (ie with big tracks and PTH) circuit board with relative ease. You aren't talking about ball grid arrays! If you're really struggling with TVR eeproms or board rework email me.

[JKY]

The handwritten 1965 is you build number - you should also find it handwritten in various place all over your car if you do any dismantling (behind door trim etc).

[spend]

markgreen said:

Went to buy new relay and got sold the wrong one. The diode in my replacement is parallel to the coil not in series.
Smoke comming from ECU :-(
So I guess the diode in the relay has allowed WAY TOO MUCH curent and burned out the power circuit on the board (not opened it yet to look.)

Doesn't seem right to me, diode is not significant like that. Sounds more like you got a completely different relay where the coil goes across the adjacent terminals rather than the opposing ones. I'd check the wiring very carefully before risking your replacement.

[markgreen]

I have had a chance to test things properly on the bench now.

The original fuel pump relay was faulty. Mechanical fault on the moving contact.
The replacement that I bought (yes I did check the pin configuration before I fitted it) is faulty and provides a direct short accross the coil.

I have a new ECU to fit and a new genuine Bosch relay.

I will update more details and progress with the repair of my old ECU on the engines and drivetrain forum.