Speedometer Needle Jumps About Erratically

Anyone had this problem or knows of the potenial causes. I have had the wheel speed sensor cleaned and aligned and the ring itself cleaned but the problem persists.

Just to add to the problem it will occasionally run perfectly but only for short periods of time before returning to being erratic. Its not a violent movement - more of a “bobbing” if that makes any sense.

Steve

It’s lack of use, so it’s forgotten what it’s supposed to do

PS & I’m not referring to my own libido either

lol…I guess I deserve that - it justs seems like there has not been that many “nice” days to roll it out the garage and go for a blat. Taking the Disco to Norway this summer also deprived it of several thousand miles, but planning a long tour of Spain and Portugal in it this summer so that should do it some good.

Dodgy connection to the wheel speed sensor. How does the wiring look?

Dodgy connection to the wheel speed sensor. How does the wiring look?

I guess I’m going to have to chase the cabling and see if there is any problem with it.

Well, it’s most likely to be dodgy at the sensor end I’d have thought, given it’s exposure. May have corroded or be getting a bit brittle.

Dodgy connection to the wheel speed sensor. How does the wiring look?

where is that then?, as mine can be a bit like that a times

Dodgy connection to the wheel speed sensor. How does the wiring look?

where is that then?, as mine can be a bit like that a times

Electronic sensor located on right hand side rear hub.

Electronic sensor located on right hand side rear hub.

If it’s S1 were talking about, Is it not the overun sensor on the right rear hub and the speedo sensor on the left rear hub?

Dave

Oops, I must have been on “automatic pilot” - it’s usually the overrun sensor which is playing up

We’re both correct on the location of the sensors. However, I completely ignored the thread title in my reply, so that was total bollox - thanks for pointing it out.

I rang a dealer up today to ask for the price of the wheel speed sensor and he tells me you can’t get it as a separtae part - it comes as part of the hub assembly…“oh hear we go”, I thought, sit down for the price and then he quoted me �57.95 + VAT. I couldn’t understand why the sensor is not a separate part and then wondered what hub assembly he was looking at for less than �60.

My parts list does not quote any part number for either the sensor or a hub assembly - anyone know a little more than me?

As an aside, in reading the service manual it states that the 340R only has a single wheel speed sensor on the left hand side and the signal is split to go to both the speedo and the ECU. It must not have worked right if they then swapped to having two sensors on the Exige?

Question then: is the left hand sensor different from the right hand one or can they be swapped over?

Steve

Tell your dealer to on a training course - the Stack sensor part number is A910E6939F …

I’m not 100% but I think the connectors are different on each side …

I am a little confussed buy this. what does each one do? If unpluged what will happend. My drivers one is very loose!

thanks Andy

I am a little confussed buy this. what does each one do? If unpluged what will happend. My drivers one is very loose!

The left hand one feeds a signal to the speedometer and so give you the mph/kph reading; the right hand one feeds the ECU and does… other things including shutting off fuelling on the overrun.

I don’t understand what you are saying is loose - the sensor itself is bolted in through a flange in its base (I think). If its loose, you need to tightened the bolt but be careful. I had a problem when I tried to undo said bolt and the head sheared off! Had to tywrap it back on as a temporary repair.

There is also the connector block a few inches back from the sensor head. I don’t think this can be loose unless the sliding metal locking piece is not slid across far enough to lock, or is missing. It is worth taking the connector apart and checking the terminals inside for corrosion. Mine was full of verdigris (blue-green coating caused by water getting into the block) and on the right hand connector can cause the 5.5k rev limiter to kick in as the ECU detects a fault.