T350 Speedo Problem

T350 Speedo Problem

Author
Discussion

pb450

Original Poster:

1,302 posts

160 months

Monday 19th October 2020
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Don’t know if anyone’s had this problem before. Ignition on and needle jumped violently to 4 o’clock position and now no longer works. Digital readout still works so I guess not a sensor problem. It now buzzes and vibrates for 1 second each time the key is turned. No flippy stuff like the Rev counter.
Tried to upload short vid. Hopefully it works.


Gladers01

592 posts

48 months

Thursday 22nd October 2020
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pb450 said:
Don’t know if anyone’s had this problem before. Ignition on and needle jumped violently to 4 o’clock position and now no longer works. Digital readout still works so I guess not a sensor problem. It now buzzes and vibrates for 1 second each time the key is turned. No flippy stuff like the Rev counter.
Tried to upload short vid. Hopefully it works.

Asssuming it's the same set up as a Tamora, try a hard reset at the dash Ecu situated in the drivers footwell next to the gas pedal, unplug for a few minutes and re connect, the other thing you can try is to jog the needle up and down via the speedo zero ref values in the set up menu, this may be enough to budge it, failing that the dash clocks will need to be pulled forward to check the power/data cables at the rear, Good luck smile

jev

384 posts

260 months

Thursday 22nd October 2020
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Strange, mine has been doing exactly the same thing for the last couple of weeks. Perhaps a case of TVR-Covid?

But I'll give Gladers' suggetion a go - let me know how you get on.


pb450

Original Poster:

1,302 posts

160 months

Friday 23rd October 2020
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Thanks Gladers, appreciated. I tried the set-up menu adjustment last night without success. frown

I'm a little wary regarding hard reset of the ECU as I haven't had the car for very long. I'm told that electronics problems can be quite common and I don't really want to 'fiddle' when I don't know what I'm doing. My speacialist is on the case so I'll see what he comes back with for now.

jev

384 posts

260 months

Friday 23rd October 2020
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Do keep me informed as my issue sounds identical. Goes 'mad' during the boot up routine with 'speedo zero' error. But the digital speedo is unaffected.

I suspect its a pod issue, maybe a dry joint? I vaguely recall having something similar a few years back.




MK_tamora

513 posts

283 months

Saturday 24th October 2020
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My Tamora has been doing that almost since the day I bought it 13 years ago! It was "fixed" twice under warranty in the first 2 years (by sending the pod away to a specialist) and was "fixed" again a few years ago by changing one of the ribbon cables.
It will work quite happily for many months and then one day will just go mad again. Usually it zeros itself at start-up and then starts going the wrong way round to about the 200mph mark and then waggles around randomly til the end of the journey. Other days it refuses to zero at start-up (with the associated dash warning) and just sits happily pointing at some random number.
I have given up messing around with it as I find it far easier to use the digital speedo anyway.

Only once has the virus spread across to the tacho dial but it zeroed again next time I started the engine.

Mine was built back in 2002.

One day I might look into it again - but then again, maybe not. I prefer to drive it than fiddle around with it.

TVRJAS

2,391 posts

129 months

Saturday 24th October 2020
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I had the same on mine 16 months ago.

This was what was described on the invoice. " new sensor,reset air gap,trace wiring loom connection."

Not had a problem since.

Edited by TVRJAS on Saturday 24th October 12:38

pb450

Original Poster:

1,302 posts

160 months

Saturday 24th October 2020
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Hmm... sounds like it’s not uncommon then.
My specialist has diagnosed a new ribbon cable as this is relatively inexpensive. On order now so will report back when fitted.

pb450

Original Poster:

1,302 posts

160 months

Saturday 5th December 2020
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By way of closure on this one, new ribbon cables fitted this morning and normal service is fully resumed.
Those cable wires are so fine, they’re made for computers not to be bounced down the road in a car. Consequently they have a life.

MK_tamora

513 posts

283 months

Saturday 5th December 2020
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pb450 said:
By way of closure on this one, new ribbon cables fitted this morning and normal service is fully resumed.
Those cable wires are so fine, they’re made for computers not to be bounced down the road in a car. Consequently they have a life.
Did you replace both cables or just one? I've bought just one but don't know which one to change.

pb450

Original Poster:

1,302 posts

160 months

Saturday 5th December 2020
quotequote all
Replaced both cables Nick. They’re cheap enough and I figured if one was dud, the other one wouldn’t be far behind.
Plus the faff of getting to them, it seemed like a no brainer. My specialist had the job done inside 45 mins.


Edited by pb450 on Monday 7th December 15:33


Edited by pb450 on Monday 7th December 15:36

rfisher

5,024 posts

283 months

Friday 11th March 2022
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Not sure if I have the same issue, but my speedo needle is moving to 120mph on its own with the car sat in my garage on a trickle charger.

I can reset it to zero by turning on the ignition, but it then moves back at some point during the week.

There's a drain on the battery once it has moved position as well.

Any ideas?

rfisher

5,024 posts

283 months

Friday 11th March 2022
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Thanks for the links.

If I can work out what the cause is I'll probably fix it myself.

Anyone had this specific fault before?

Remember how it was fixed?

LucyP

1,698 posts

59 months

Friday 11th March 2022
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Maybe contact one of the companies that I suggested and ask them if it's an easy fix that you can do, or whether you need to send the instrument pack to them. I have a great guy who I phone up when the gates go wrong at home. If it can be fixed over the phone, he asks me what fault codes are showing, and then talks me through what to press and change in what sequence to fix the problem, or if the code shows that it can't be fixed over the phone, he comes out and sorts the problem. Good technicians are like that when they run their own business.

On here, you will get 300 different responses, and before you know it, once you have tried a few of them, your instrument panel will be scrap.

MK_tamora

513 posts

283 months

Friday 11th March 2022
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Sounds like a subtly different fault to me.
By coincidence I pulled out the dash ecu this afternoon to see if there were any dry joints on the D-type connectors. I can't see any but I did find that one of the PIC carriers has been cracked - probably by somebody trying to lever it out with a screwdriver!
I'll be getting it replaced as soon as the parts are available, but none in the UK at present apparently.


TVR Tommy

613 posts

225 months

Friday 11th March 2022
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rfisher said:
Not sure if I have the same issue, but my speedo needle is moving to 120mph on its own with the car sat in my garage on a trickle charger.

I can reset it to zero by turning on the ignition, but it then moves back at some point during the week.

There's a drain on the battery once it has moved position as well.

Any ideas?
When it does it try unplugging the speed sensor (in the boot left hand side of my T350). See if it goes back to zero. If it does it’ll point towards a faulty sensor.

LucyP said:
On here, you will get 300 different responses, and before you know it, once you have tried a few of them, your instrument panel will be scrap.

LucyP making more friends in the TVR community. That’s very useful advise about fixing your electric gates right there.

Edited by TVR Tommy on Friday 11th March 20:39

LucyP

1,698 posts

59 months

Saturday 12th March 2022
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It's true though. Someone on here spent 2 weeks and 3 pages of posts fixing his fuel gauge sender. Another have-a-go hero. The garage would have fixed it in 10 minutes, whilst he waited.

Sometimes this forum cannot see the wood for the trees. Because it's a TVR, they somehow feel that they have to have-a-go. If it was their Fiesta, they would just go to a garage.

It's called being sensible, as my gates example demonstrated.

GaryF

970 posts

253 months

Monday 14th March 2022
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My Tuscan had a similar problem, but I only noticed it whilst driving - the speedo would go ballistic and bouce round to the 120 lepton region and fluctuate all over the shop, reporting every speed other than that actually being travelled at. It was the speed sensor.

Having it do it whilst on a charger and with the ignition off, well I suppose it could still be the same problem. Hope you get it resolved and can report back.

Edited by GaryF on Monday 14th March 20:50

rfisher

5,024 posts

283 months

Tuesday 15th March 2022
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Think I need a nice long test drive to see if the speedo behaves all the way up the dial driving

The fault hasn't come back since I reset the dials a week ago.

No excess drain on the battery either.

She was probably just letting me know that it's time to hit the road, now that the weather is improving.

TVRs get bored during their winter hibernation.