STX 550 speedo error

[blackpete]

My stx 550 speedo reads high 7km/hr so if its says you are at 100kms/hr you
are really doing 93kms have checked with GPS . Has anyone else had this ? seems to be about the same at all speeds maybe a bit more out over 110 ...

 

[nuthanav]

ST-X 550 speedo error

Yep, mine too. As far as I know the vehicles speed is taken from an ABS sensor at the right front wheel. (Someone else may be able to correct me on that). As far as I know there is no way of adjusting the ABS signal to the speedo to correct for the speed shown. (I can be corrected on that too). As I understand things, the only way to correct for the indicated speed is to change to a larger tyre size. That's what I will do when the time comes. In my view, anything with something like a 7% error is pretty sloppy engineering, particularly when it can't be be "field corrected".
Only good thing is it might save a few $'s on speeding tickets!

 

[bods]

I think you will find this has been mentioned numerous times across all models. It is a speedo needle error and they don't have to fix it, as according to the australian design rules it can show "up to 10%" faster than the vehicle is travelling, but may not indicate a speed slower than the vehicle is travelling. If you hook up one of those bluetooth adapters and use an obd2 program, you will find the ecu is pretty close to spot on with a gps speed. It is the needle accuracy that is a problem. Fitting bigger tyres will correct the speedo, but then your odometer will be incorrect

 

[blackpete]

Yes it is a speedo needle error. I have a al619 scan tool and reads road speed which is correct.
all the way, so the ecu is good. I think they must do this on purpose and not just Nissan.
I know Jaycar have a speed corrector module at about $40 which you can put on speedo to adjust indicated speed. I don't know how easy it is to get dash out to do this maybe someone else has done that if so let us know.

 

[Old.Tony]

It's definitely a speedo needle error. The ECU is quite accurate on standard tyres, it's purely in how much the needle is deflected.

The Jaycar unit is useful if the speedo uses the gearbox revolution sensor, but the D40s all use an aggregate of the 4 ABS sensors to provide the input to the ECU and the ECU sends a steady voltage (not pulses that could be adjusted by the Jaycar unit) to the instrument cluster.

So, long story short: if you want an accurate speed reading, a GPS is the best source.

 

[nedm1989]

mine was 7% out too, since then I've fitted 265/70/17's and it is pretty much dead on maybe 0.5% out now but still under

 

[JLA]

if you want an accurate speed reading, a GPS is the best source.

My feelings too. I went to eBay a while back and purchased a heads up GPS speed display. Described as accurate etc.etc. Well guess what it overreads by 5klm - much the same as the speedo.
I sent that one back and replaced it with a heads-up Polaris. You can set an offset. If you want exact speed or if you want a safety factor of a few klms/hour then you can set the offset.
The Polaris cost a bit more but a great solution.

I have the built in D40 550 Navara navigator with maps that have never been updated - not giving Nissan $700
Also a Tom Tom GPS which gives me map speed. The overspeed warning auto adjusts to suit whatever the speed limit is. Mpas are free update.
Polaris heads-up GPS speed indicator.

One day a car manufacturer will get it all together.
Nissan must be the only Manufacturer that does not have free or reasonably priced map updates. I don't know who or why anyone would pay the $700.