TVR T350 dash/starting woes

[Ian Abel]

Hi people
I recently purchased a T350 after 7 years ownership of a Chim. On the journey back from picking the car up the heater stopped working and I noticed the trip and mileage was 000000. Car drove ok otherwise. Got the car back in the garage and the light switch light and dash stayed on when ignition key was taken out. Left the car on trickle charge. Tried to start the car today and now have Fram 148 message and car won’t start. Battery low as said 11.8 on charger.
The ECU that I’ve read about is the metal box in drivers footwell on right hand side, behind a cover? If I remove the 3 connectors (?) from the top of the box I guess the ecu will come out? If I then replace the CR2032 battery will that solve the dash staying on and draining the battery? Will I do any other damage to the electrical system in the process? It’s booked in to see Colin but he is a 1 1/2 hour drive away so I need to be able to drive him.
I just don’t want to make things worst, as electrics aren’t my thing, but at the same time I’m happy to try and replace the dash battery if that helps me.
Many thanks in advance
Grateful new 350 owner Ian

[maxkressbronn]

Hi Ian, looks like some bad luck you are having here. I am not sure the battery in the dash ECU is linked to the light issue. However, changing it you should keep the ECU connected to the main battery for not loosing the entire memory. Hopefully only the ribbon cables are playing up or came adrift.
Regarding the light issue it might probably a sticking relay in the Relay and Splice unit under the center console trim, Jody from Python can fix this. In the meantime just pull the main light relay or fuse to save your battery, refer to your handbook.
Good luck, Markus

[alex_gray255]

Unfortunately the dash ECU is separate from the engine ECU. If the dash ECU starts acting up and it does not reset then it is usually a trip off to a place like Python Racing.

[Ian Abel]

Update...........was fiddling with the dash ecu (?) in drivers footwell. Before deciding to disconnect I wrote original post. While waiting to see answers before doing anything else I put it back where I found it. Dash no longer stays on when I remove the key and the heater is working again!!! Light on light switch still stays on tho. Still no mileage or trip.
Got to love tvr electrics

[pb450]

Try replaciong the 2x delicate ribbon cables. They're not expensive at £15 the pair. Can cure a multitude of problems. Ask how I know...

[TV8]

pb450 said:

Try replaciong the 2x delicate ribbon cables. They're not expensive at £15 the pair. Can cure a multitude of problems. Ask how I know...

Hi Peter, how is the T350 - you pleased with it? Look forward to seeing it sooner rather than later!

[Gladers01]

Ian Abel said:

Update...........was fiddling with the dash ecu (?) in drivers footwell. Before deciding to disconnect I wrote original post. While waiting to see answers before doing anything else I put it back where I found it. Dash no longer stays on when I remove the key and the heater is working again!!! Light on light switch still stays on tho. Still no mileage or trip.
Got to love tvr electrics

Try pressing the brake pedal to get the dash/light switch off as a temporary fix, could be a problem with the alternator rectifier diodes short or low resistance back feeding the dash, the ignition relay 33 can also cause this if slow to unlatch or stuck on, swop with fan relay 23 to test.

The mileage and trip resetting to zeros after every drive was the dash pod battery that needed replacing on mine, at least the heater's working, turned colder than a witch's tit !

[Granturadriver]

FRAM stands for Ferroelectric Random Access Memory. It is a memory in the ECU. Such memory errors mean that nothing can be stored. However, I am not clear what fault 147 means.

I had in the car once fault 247. only sending to a specialist for repair was helpful. It was not the battery for the clock nor any of the ribbon cables.

[s3dave]

Sounds like a Dash ECU problem, speak to Paul Smith, he helped me with fault diagnosis over the phone and then repaired the Dash ECU; turned it around in a day and simply charged me time and materials. Paul worked for TVR, you can even see his name at the bottom of some of the original wiring diagrams. PM me if you need his number.

[Granturadriver]

Paul helped me with my FRAM fault as well. He runs his homepage http://pselectronicsolutions.co.uk/about.html

[TR4man]

Did you buy from a specialist?

If so, can’t you get them to investigate the faults and fix them under warranty?

[Ian Abel]

TR4man said:

Did you buy from a specialist?

If so, can’t you get them to investigate the faults and fix them under warranty?

It’s booked in to see tvr dealer as has 3 month warranty luckily but I’m just worried I will get stuck somewhere not being able to start the car

[Ian Abel]

pb450 said:

Try replaciong the 2x delicate ribbon cables. They're not expensive at £15 the pair. Can cure a multitude of problems. Ask how I know...

Where’s the best place to buy them, eBay????
Do they just push in the light switch and ecu like a computer and printer?

[Ian Abel]

Well that lasted long then......dash lit up again as per light selector switch so draining the battery again . Getting peed off now.

Edited by Ian Abel on Tuesday 29th December 21:38

[Ian Abel]

Ian Abel said:

Well that lasted long then......dash lit up again as per light selector switch so draining the battery again . Getting peed off now.

Edited by Ian Abel on Tuesday 29th December 21:38

[Targarama]

From memory, this could be 2 separate issues. The battery in the dials and something else. First I would check and replace the inline fuses from the alternator (under airbox) and in the footwell), and then check the earths are all tight. TVRs like other modern cars throw up all kinds of funny behaviour with bad earth connections (happens to McLarens too!).

[pb450]

Ian Abel said:

Where’s the best place to buy them, eBay????
Do they just push in the light switch and ecu like a computer and printer?

I believe mine came from Racetech Direct. I wouldn't go for the cheap ebay ones, false economy in my opinion. Give them a call to ensure you get the correct ones. Push fit between the back of the spddeo pod and the ECU on the right side of the driver's footwell.

[pb450]

TV8 said:

Hi Peter, how is the T350 - you pleased with it? Look forward to seeing it sooner rather than later!

Hi Graham, yeah, really loving it. Although the chance to drive it has been limited since I've had it. Totally different from the Chimaera but so far I'm reallly pleased I've made the change. Ask me again after next summer, when I've been some paces in it.

Yep, look forward to showing it off when we can all meet up again. Vive la Vaccine!

[Gladers01]

Ian Abel said:

Ian Abel said:

Well that lasted long then......dash lit up again as per light selector switch so draining the battery again . Getting peed off now.

Edited by Ian Abel on Tuesday 29th December 21:38

My advice would be to charge the battery and take it back to the dealer who supplied it if under warranty - nothing worse than being 'spotted' on a low loader during the festive period

[robsco]

I had a similar issue with one of my T350s. The dash stayed on permanently, unless the brake pedal was pressed. It turned out to be alternator failure.