VIN:- JTEHH20VX00239182
2.0 ltr

This has an intermitent loss of Vehicle Speed Sensor signal. There is a good 12 volt refernce & ground at the sensor (sensor is new too). When I scoped the sensor output yesterday when the fault wsa preesent I witnessed a very small square wave output in the region of 150 - 350 mV. The voltage on the signal wire with the sensor unplugged was 400 mV.

Whilst I was trying to put a signal up wire with a sensor simulator, I noticed that the voltage shifted from 400 mV to battery voltage. At this point the speedo started working (with a good full scale square waveform) & has done ever since.

I really need a wiring diagram to go further. Autodata & vivid dont have it. We have traced the blue wire with black tracer back & it doesnt go to the Engine ECU.

Any help would be most appreciated.

Thanks in advance

Dave

Sorted!

Found a bad connection in a junction box on the drivers side A pillar.

Sorry for wasting your time.

Cheers

Dave

Dave,

At least you've posted the fault/fix as it may be a common fault. Strange how it suddenly started working when forced with a sensor simulator though.

Hi Dave,
A bit off topic but what sensor simulator have you got,where did you get it & is it good.Been after one but not sure which.

Cheers
Matt

Hi Matt

It's a Sykes Pickevant DSS (Old model) that came bundled with the workshop equipement when we bought the business. It serves its purpose though. I expect the latest Sykes unit will do what it says on the tin also.

I find it is most useful when you find a faulty component & you want to prove that the light will go out after you spend 150 quid of your customers money.

Cheers

Dave

i've got the sensor simulator built into my old smart unit but the problem i've found is the resistance range doesn't have enough varying range.

When i was trying to test a Fuel filler cap operation on a Citroen C8 the range wasn't enough to test it. Resistors from Maplins was the answer
(15 ohms & 150kohms).

http://www.rwmotortec.com/sensor/

Try this link i bought one of these from china before they were being imported and has worked well so far.

ATB
Nev

Hi Dave
Sorry it's a bit late but Ive had same problem on RAV4 before. The connector block in the drivers kick panel had corrosion in caused by a non genuine windscreen leaking. Apparently the non genuine screens cause this fault often.
Mark M