Speedo Problem

[jacko16]

I have a Toyota Aurion Peseara,03/2007. The speedo is giving innacurate readings. For example, on my car GPS, it shows 100kmph, the speedo shows 92kmph. I checked with Toyota and they said they will have to change the instrument pannel to fix this problem. Has anyone elese come accross this problem?

[SCOOTA44]

Yes it is a common problem, but if you know the difference in speed you can adjust your speed to suit. or as I sometimes do quick check on the GPS. I presume the presara has the same dash as the sportivo range ?

[DJKOR]

When designing a speedo, there can be anything up to 10% error (optimistic) in the readings given. Here it appears your reading is in the opposite direction though. To correct this though, they can either replace the speedo, or you can fit an aftermarket speedo corrector which modifies the input speed signal.

One thing to remember as well though is that your GPS isn't 100% accurate when giving your speed. I wouldn't rely on just the GPS alone to give you an indication of how much your speedo is off by.

I believe the Presara uses the speed signal as well to calculate it's speed (which is the same one that the speedo receives), but there is always the possibility that the nav unit may also be in error. There is no guarantee that changing your speedo will completely fix your issue.

[adventurer007]

Get it changed. The current ADR prohibits under-reading.

http://www.trafficlaw.com.au/speedos.html

[private number]

how accurate are the GPS readings for your speed though?

[czaja74]

I would like to know about it too. My Touring reads 4-5 km undr. I drove 95km/h on cruise control for about 7 min. Gps was steadily showing 100km/h. I used this GPS in my '04 Altise and speedo was exactly same as GPS. Therefore I can safetly asume that Aurion speedo is out. Asked the dealer about it and was told that it was ok and within guidlines. However reading this article it seems that it is not. I'll try to ak to the dealer again and get whole thing changed.

[mr_grumble2010]

Mines the opposite. Cruise set to 100km/h and GPS reads a steady 95.5km/h

You can play with tyre profiles to correct the speed difference which I successfully did with our Pajero, gave me an additional 4km/h but it did effect the pick-up of the vehicle as well as fuel eccomony.

However if your displaying a lesser speed than what your actually travelling, as joelau007 stated, the Australian Design Rules dictate that

The current ADR prohibits any under-reading:

"5.3. The speed indicated shall not be less than the true speed of the vehicle. At the test speeds specified in paragraph 5.2.5. above, there shall be the following relationship between the speed displayed (V1 ) and the true speed (V2).

0 ≤ (V1 - V2) ≤ 0.1 V2 + 4 km/h."

This formula means that the vehicle's actual (true) speed must not be greater than the displayed speed. (Displayed speed minus true speed must be greater than or equal to 0, and less than or equal to 4kmh plus 10% of true speed). This means that if your vehicle's actual speed is 100kmh, the displayed speed is permitted to be anywhere between 100kmh and 114kmh.

Steve

Edited April 17, 2010 by mr_grumble2010

[Silver-Aurion]

Under reading is definitely something that should not happen and does need to get fixed. Mine overreads by about 6KM/h. So if my speedo shows 60KM/h I'm really doing about 54Km/h.

I'm not complaining though(I love it like this, it keeps me from getting a fine), I rather it overstates.

[00UCH]

your speedo is always under, covers the dealers my gps says 100km/h my speedo says around 93-94km/h. hence when i drive in 100 or 110 zones i sit on 109 in the 100 zone and 118-119 in the 110 zone :) i do this past mr police man all the time have been since i started driving never a problem.. Police also allow a 10% margen as well.

[Adamsy]

Guys Toyota's by nature always read under usually by a margin of about 6%, you'll find pretty much all Toyota's will read between 4 and 6kms under whatever your Speedo is displaying. My car with 19's reads about 6 kms under and the Hilux's and Hiace's at work read about 5kms under. :)having a few kays margin can be a good thing though?

[DJKOR]

your speedo is always under, covers the dealers my gps says 100km/h my speedo says around 93-94km/h. hence when i drive in 100 or 110 zones i sit on 109 in the 100 zone and 118-119 in the 110 zone :) i do this past mr police man all the time have been since i started driving never a problem.. Police also allow a 10% margen as well.

The part I've put in bold is the type of issue the OP is stating. You have stated one thing then said the opposite. The OP is having a case where he believes his speedo is showing a speed under what his actual speed is. The scenario you have stated in the following sentences is when the speedo shows a speed over what your actual speed is.

[00UCH]

iv stated my car dose the same thing along with my mums hilux, I fix the problem by adding about 7km/h ( on my speedo ) when i drive, but only in 100 + zones... how have i stated anything else???

In a 100 zone i sit on 109km/h on my speedo gps says about 102km/h, 110 zone i sit on 118-119 on my speedo gps says 112km/h...

Edited April 22, 2010 by 00UCH

[GSV40R]

i have yet to see a toyota in australia that UNDER reads. They all OVER read.

the speed signal sent from the ecu to the speedo unit can be read the the IT2 and in most cases it is within 1 or 2 klms to a gps. The speedo unit is adjustable by the manufacturer (flexdrive i think). If you have an issue that the vehicle is slower than the actual speedo reading , then your local dealer has a form it can send of the the manufacturer and get a replacement unit that is closer to the correct speed (if it is still within warranty). Note these vehicles are built in victoria , dont quote me , but the government's wipe off 5kph campaign has sway vehicle manufacturers to errr on the conservative side , not that hey will admit it though.

as stated earlier there is an Adr that states speedo inaccuracies , but if the vehicle is "standard" ( without 20inch rims)i doubt you will see a toyota speedo under read .

[00UCH]

mine reads under when i have my standed 17" on put my 20" on and it may change 1km/h but still under by about 6km/h to what the gps says.

[DJKOR]

iv stated my car dose the same thing along with my mums hilux, I fix the problem by adding about 7km/h ( on my speedo ) when i drive, but only in 100 + zones... how have i stated anything else???

In a 100 zone i sit on 109km/h on my speedo gps says about 102km/h, 110 zone i sit on 118-119 on my speedo gps says 112km/h...

No you haven't stated the same thing. Yes I'm being picky, but for the discussion here, it's the difference between a valid problem, and something that can be disregarded.

You state your speedo says 109km/h, and your GPS states about 102km/h...

The OP states his speedo says 92km/h, and his GPS states about 100km/h.

Those are complete opposites. Notice how your GPS shows a speed lower than your speedo and the OP's GPS shows a speed greater than the speedo?

Read the post again if you don't believe me.