speedometer calibration

[Scorpius]

Originally Posted by SMG

Scorpius: The speedo error is built in so the car is ALWAYS travelling slower than the speedo indicates as long as you're not running oversized tires. No worries about a ticket as long as you and your family obey the speed limits.

I think I mis stated my issue, I'm going faster then the speedo says by 10 MPH.... if the speedo says 60, I'm traveling 70 MPH, if I'm driving 50 by the speedo, then I'm traveling 60 MPH, so @ 10 MPH over, might be a target for ticket. I try and drive 10 less then the speedlimit, but thats a pain, and under 40 MPH is off by 5 MPH... I would not mind if it was slower then speedo, but faster to me seems an issue.

[SMG]

Wow and you've checked this with GPS?

[dmbluebeetle]

Originally Posted by Scorpius

I think I mis stated my issue, I'm going faster then the speedo says by 10 MPH.... if the speedo says 60, I'm traveling 70 MPH,

on another note I also notice the odometer is slow by .8 or so then my GPS, my trailblazer was right on both speed and mileage with the GPS, would the speed being slower on the speedo then reported effect my odometer, I thought I read these are separate.

If the Speed reading and the odometer are both slow, then you are possibly not getting the correct signal from the sensor, both the speedo and odo use the same pulse from the sensor. I would start at the other end of the system for this problem, you should start at the transmission first.

[Scorpius]

Ok ordered a new Speed sensor for 38 bucks online. worth a shot tho start there. was on a long drive today and calulated the Odometer is off by .2 per mile, so @ 10 miles, I really travel 12 and @ 100 miles its more like 120.

Basically I take the miles driven divide by 5 and add the result to the total. Made a big differance in MPG, more in line to what it should be now. So odometer is for sure off with the speed issue.

On another note, I pulled an idiot thing and left the light switch pulled out and the parking lights stayed on all night and the battery was dead (I know, I know) anyways jumped it off and eveything seems ok, but now the cruise Control does not work.... any quick suggestions on this, I may post a new thread on this....

Thanks everyone for all the advise, will let you know how this turns out, sensor should be here by the weekend, looks at detials to replace, going to be a chore, but looking forward to the challange.

[Turbomania]

Cosmo.... Why are running such a high tire pressure??? Tire pressure for our cars has carefully been researched by VW on their tracks and is posted several places on our cars. I run 215-55/16 tires and run the recommended 28 to 29 in the front for around town driving and 27 for the rear. It provides the best ride and handling. For High speed driving with a load I bump that up to 30-32 front and 28 to 29 rear. It is always good to run less air in the rears on a front wheel drive car due the weight bias toward the front. With 35 PSI you will wear out the middle of the tread on your tires before the edges catch up. For even and long tire wear follow the VW suggested pressures. It's worked for me very well. JK

[noR]

I usuually run 32-36psi with no noticable wear-pattern problems on my tires.

There's quite a bit of wiggle room there.

[dmbluebeetle]

Originally Posted by Scorpius

Thanks everyone for all the advise, will let you know how this turns out, sensor should be here by the weekend, looks at detials to replace, going to be a chore, but looking forward to the challange.

See if you can get a look at the part in front of the sensor too, and make sure there is nothing wrong with it also.

I wish my other computer was running so I could look at my Bentley service manual

[Scorpius]

Ok, new Speed sensor is installed and........................

Same issue

Good news is, exchanging the sensor was not that bad, few cuss words and some very dirty hands and arms, but took about 20 min and did not have to undo the tranny mount.

I have a VDCS kit coming in today as well. so going to see if it can tell me anything, plus I think the Cruise control is off in the computer as it has not worked since I killed the battery the other day, I read by defualt its disabled in a New ECS, can not hurt to find out.

New symptoms also to reports, sometimes the speed is only off by 5 MPH when just getting going, then as speed increases so do the gap till its a constant 10 over for anything above 35.

The Bently forum replied that it sounds like the internal wheel inside the tranny and thats its cracked or damagaed, which is a very labor intensive job with special tools, I would think i would be getting erractic behavoir if that was the case, like a bouncing needle , or it jumping at times. Its steady and true just off by +10 to 20%.

will post again after I play with the VDCS software and cable and see what it reports back.

[dmbluebeetle]

Originally Posted by Scorpius

Ok, new Speed sensor is installed and........................Same issue

The Bentley forum replied that it sounds like the internal wheel inside the tranny and that its cracked or damaged, which is a very labor intensive job with special tools, I would think i would be getting erratic behavior if that was the case, like a bouncing needle , or it jumping at times. Its steady and true just off by +10 to 20%.

If the internal wheel is cracked it may be slipping on the shaft which would cause the speed sensor to not receive speed pulse correctly. I was hoping you might have looked at it while you had the sensor off if that was possible.

Can you post a picture of the old sensor? I am curious to see what it looks like......if possible the side that fits into the transmission.

[Judee]

I don't like that Nubz' speedometer and odometer spin faster than they should... that means I'm accuring mileage (and depreciation) faster.

I tested this with one of those roadside Sheriff's speed-warning trailers with the bright yellow speed displays, and a GPS. When my needle is pointed at 33-34, I'm really only doing 30. Which means it's spinning 10-13 percent too fast!

I plan to fix this with oversized tires... pics coming soon .

[Scorpius]

you can not see anything on where the sensor plugs in, attached is the end from the old sensor that plugs into the tranny, you see the little arm in the middle, that slided into a hole on the adapter on the tranny, so nothing to see.



On another note: I bought the VCDS software with cable and Bently DVD, ran the Instrument test and it failed on the Chime, buzzer test, would not do any of them. Also my Speedo failed the analog test, it only went 90% of the range then was correct at the 2nd part pointing to 65 MPH. I then drove down the road with the VCDS running on the laptop and it to is about 10 MPH off, so it seems I'm getting the right signal in, but the speedo is off.

I'm wondering of my instrument cluster is bad? No buzzer (From what I have read it seems these are in the cluster?) Speedo and Odometer off. Do not really want to spend the money on a new one if the old one is good and issue is elsewhere, finding more and more noticed the clutch switch does not work, car starts with the clutch in or not, switch at the clutch is good with ohm-meter. Its like its bypassed...

[Scorpius]

Oh, cruise control is working again, I ran the TBA procudres with VCDS and that seems to have corrected something, as its working now.

[Scorpius]

UPDATE, using Vag-com I adjusted the Distance Impulse Number from a 1 to a 4, and WHAM! Perfect reporting, and I mean dead on for the speedo, the Trip is still lagging but not as bad, it was .2 off for every mile, now more like .05 per mile thats 15 miles more accurate per 100 driven., ( 1 was adding 20 to every 100, now have to add only 5 to every 100 to be closer, I get paid per mile driven, so need this as close as possible)

Now the bad part: it through my Odometer from 83,000 miles to 98,800 miles. wondering what the normal Dsitance Impulse number is suppose to be and if it was dropped to roll the odometer back which caused the speedo errors, does any know what the deafult value from the factory is? Since I'm dead on, I'm betting its higher then 4, since it should be reports faster then driving and I bet this would fix my trip odometer reporting as well, not to mention I want to go back to the guy I bought this from 3 weeks ago and inquire to if he used Vag-com or similar?

[Scorpius]

OK, figured it out, correct setting is "2", Trip and Odometer are now dead on and the speed is reporting slightly higher then travel, which means its working the way its suppose to.

However this again played havoc with my Odometer reading which now read 102,000 miles, if I set it back to 1 it goes back to near where I bought it at, 82,000... So question is who changed it to begin with ?????????

No sure there is much I can so about it at this point, but 20,000 miles is a big differance, but love the car. Only thing not working now are any of the warning chimes and buzzers..

So if you test drive a NB, take you GPS along if your going 10 MPH slower then the GPS and your mileage is off by approx .2 per mile, then chances are someone fiddled with the codes and you might not have the correct odometer reading.

[dmbluebeetle]

Thank you for the picture. does the square shaft spin inside the housing?

I had no idea there was such a thing as a "Distance Impulse Number"

I'm sorry to hear about the Odo jumping miles, I don't know what to do about that.

[CoriBug]

Here's a related question - I watched my odometer and the trip meter turn over yesterday. The trip meter moved 1/10 of a mile (i.e. 436.2 to 436.3) and the odometer moved a full mile at the same time (i.e. 77789 to 77790). Shouldn't they both turn over a full mile at the same time?

[FarrisK]

Originally Posted by CoriBug

Here's a related question - I watched my odometer and the trip meter turn over yesterday. The trip meter moved 1/10 of a mile (i.e. 436.2 to 436.3) and the odometer moved a full mile at the same time (i.e. 77789 to 77790). Shouldn't they both turn over a full mile at the same time?

Nope. You can reset the trip meter at any time during the currently displayed mile in the odometer.

[Scorpius]

Originally Posted by dmbluebeetle

Thank you for the picture. does the square shaft spin inside the housing?

I had no idea there was such a thing as a "Distance Impulse Number"

I'm sorry to hear about the Odo jumping miles, I don't know what to do about that.

Yes the shaft spins and generates the voltage to send the signal out.

nothing to do about the mileage, my guess is its showing the correct mileage now since the speedo and Odo are correct, think I was mislead, not sure if by the dealer I bought from or before him. Have not questioned him yet, the car fax shows normal odometer reading for the life of trhe car, nothing wierd though. maybe the odometer was replaced at some point and it was reporgrammed wrong and the mileage set, so no telling how many miles it actuallly has. I know if you replace the cluster you have to reset the mileage to the current mileage or your suppose to, you can use Vag-com to increase that number but not decrease it for obvious reasons..


the setting should be a 2 which it is now, it was a 1, which makes the mileage the lowest on the odometer of the setting of 1, 2,3, or 4. 2 and 4 are the only recommededed setting, @ 4 the speedo was dead on, but odometer was off by .025 per mile. @ setting 2 speedo is slightly higher then actual speed, but Odo is spot on. and I do not might it being higher speed then traveling, just do not like it the other way around.

I guess I will leave it @ 4 till I need service and then change it back to 1 so it continues to show the previous reported range till my 24 month, 24,000 mile warrenty expires any way, then will just leave it @ 4.. its that or replace the speedo

[Judee]

So I fit some new (larger diameter 225/45ZR18) tires this past weekend, and it fixed the speedometer problem perfectly.

I verified with my GPS: 70 mph on the dial now means 70 mph on the GPS.

Judee's 2008 Yellow New Beetle

[CoriBug]

Originally Posted by FarrisK

Nope. You can reset the trip meter at any time during the currently displayed mile in the odometer.

Doh!

Thanks