Hi all,
I’ve recently developed an ABS sensor fault on the front left wheel, now I’m aware that this unit is also a wheel speed sensor. After doing some reading on the Internet i’m led to believe the speed reading on my 2002 1.8 svt sport is electronic with an average of all four sensors providing a speed reading on the speedometer.
Can 1 failed sensor cause my speedo to read an inaccuracy of +10mph on average or am I seeing a deeper problem?
thanks as always.
Maybe these people do not understand what this part is for.
After a lot of reading there are 5 parts to this electronic system, the speed sensor located in the gearbox turret & 4 ABS/Wheel speed sensors…
Before I spend out on different parts I’d like some advice based on experiences people have had or genuine technical knowledge, has the issue always been the sensor in the gearbox or will an open circuit malfunction of a failed ABS/Speed sensor cause my reading…
My speedo is working, it never drops suddenly, it’s just inaccurate and it started running +10mph a week or so after my ABS light came on perminantley.
It appears to be linked but info on the Internet suggests the part you posted, hence my question.
The wiring diagrams indicate that the speed sensor feeds into a separate micro-computer (location of that not shown) which also has no feed from the ABS unit. The actual speedometer and the Tach. get readings from the Micro-comp. so any information you’ve read doesn’t hold water as far as the electrics are concerned.
Averaging readings between all four ABS sensors and the speed sensor are illogical, what happens when you brake, go round corners, the diff kicks in, etc? Speed readings will fluctuate (they don’t)
My impression - as often happens, people make assumptions, in this case seemingly way off base. If you’ve downsized the wheels, and got the tyre selection wrong, then speed readings may be affected, (a problem I had*) but a constant read of +10 mph (across the speed range?) would indicate a speed senor fault.
Great information Gerryn, thank you.
I had another thought this morning - whats the static reading on your speedo? Is it reading zero, or 10 mph? Even one section reading will add to apparent speed, which may be exaggerated when you reach Legal motorway speed.
Not a usual circumstance, but if you (like some) have had the needle off to paint it, then it’s possible it wasn’t zeroed after replacing it. You’ll probably say “No - haven’t done that!” - But it was a passing thought.
The static or resting position is indeed zero, (sitting on the pin) and nope, I’ve not removed it. Good thought though.