Jump to content
Click here if you are having website access problems ×

CSR odometer/mileometer under-reading...


Shortshift

Recommended Posts

  • Leadership Team

2005 CSR260, just fitted with a new speedo pick-up/sensor by the offside rear wheel prior to me getting the car.  Speedo works fine (well, a bit of needle wavering at low speeds, but rock solid from around 50mph up) giving accurate mph readings.

But the odometer is under-reading.  I'd say its about 33% out - so it increments by 2 miles when the true distance traveled is around 3 miles (I haven't had a chance to check this accurately, yet, but it's there or thereabouts). 

Strange, surely, that the speedo appears to be accurate but the odo is out by that margin.

Anyway - any ideas for me, please?

James

Link to comment
Share on other sites

  • Member

Yes, it is strange.

  1. Have you checked the speedo against a GPS device?
  2. Do you have the manual with the settings so that you can check that they match your gearing and wheel size?
  3. Can it be set so that speed reads in kms and distance in miles or something similar?
  4. Check that you're not dropping any pulses by watching the telltale light as you turn the wheel by hand.

Jonathan

Link to comment
Share on other sites

  • Leadership Team

Thanks Jonathan:

1.  Not yet - but the error is sufficiently gross for this not to be relevant at the moment

2.  No change in wheel and tyre size...  but what's this about 'settings'?  That's the sort of thing I'm keen to know more about.

3.  On the to-do list, but I suspect that errors originating from this would affect speedo as well as odo?

James

Link to comment
Share on other sites

  • Member

2.  No change in wheel and tyre size...  but what's this about 'settings'?  That's the sort of thing I'm keen to know more about.

You have to input a factor that matches your wheel size. That can be done from a table in the manual or experimentally. I'd like to know that the current factor is what you'd expect. (Please ignore the comment about gearing, it's been a long day). 

3.  On the to-do list, but I suspect that errors originating from this would affect speedo as well as odo?

Me too. But there's a relevant Sherlock Holmes quote... 

Jonathan

PS: I added another thought to post #2.

Link to comment
Share on other sites

  • Leadership Team

I'm familiar (and reasonably adept) with the 'settings' menu on a car fitted with the Stack instrument pack, but I've got 'swoopy dash' in this CSR with conventional circular dials.  I'm not aware of any settings to be inputted (nor where, or how) for this type of dash and instrument set-up but if  there are settings to adjust then it would sound like the way to go!

Anyone know more?

James
 

Link to comment
Share on other sites

  • Leadership Team

Thanks - this thread (from '1' above) sounds promising, and refers to one of the points you made earlier:

Untitled_0.jpg.dbee768440bea49d9d44a9f66ba7a137.jpg

Looks like revisiting the sensor installation and checking gaps, etc, is probably next on the list.

James

Link to comment
Share on other sites

Hi James, I had the same reading issues on my 2018 car and it was cured by sensor gap adjustment. The LED indicator is not easy to see . Its a low strength green coloured LED that glows from the end of the sensor, where the wires attach. I recall that the nominal setting was 1mm but mine worked best at 0.9mm, My speedo and milometer now read exactly as my GPS.

 

  

Link to comment
Share on other sites

Hi James,

WN572 sent as requested.  But looking at your original post, I suspect the problem may have more to do with the sensor air gap than electrical interference.  Or it could be a combination, of course!  Follow the link in JK's post #7 for info on how to fix both.

(I'm assuming a 2005 CSR has the same sensor set-up as the S3/SV cars.)

JV

Link to comment
Share on other sites

  • Leadership Team

Thanks John - I replied by PM to thank you for the WN, and also your directions (as originally pointed out by Jonathan) to the Technical Guide that you have co-authored and placed on the site.  I'll work through methodically - though slightly more in hope than in confidence, given that the speedo is working properly and it's just the odo that is out.

I'll report back here when I eventually get it resolved (car not here to work on at present).

James

Link to comment
Share on other sites

Just had this problem myself and the fix was down to making sure that the light went off all 43 times for each notch on the drive shaft. On mine, it was only reading 33 of the 43 so creating the same error as yourself. The 10 it wasn't reading, or more to the point reading as one, were all in one area. Moved the out a tad and rotated the hub to get the count right and hey presto. Odometer spot on, speedo slightly high according to sat nav.

Link to comment
Share on other sites

  • 10 months later...
  • Leadership Team

Just to close this off, even though it has taken 10 months or so. 

Firstly, I can confirm that working through the set-up instructions as per John V's excellent guide means that the speedo and odo work now consistently and reliably, so taking the time to check the alignment (my sensor was not anywhere close to tracking the centre of the toothed wheel) and the air gap between sensor and wheel is worthwhile.

I was then left with speedo readings that looked to be around 8% optimistic (comparing the instrument reading to GPS speed) so a quick adjust of the speedo calibration (sequence of ignnition key and odo reset button pushes) and that is now fine as well.

Just love it when a plan comes together.  Very satisfying!

James

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...