VW Passat 2004 MPH display incorrect

[z786]

Hi, i have a passat here, TDI, The MPH needle does not go above 30MPH no matter what speed you do, ABS sensor readings seem to be fine but cant check them above 24km/h because abs module locks out due to safety

the mileage does not go up as normal, eg a 40 mile journey wil clock maybe 12 miles

anybody got suggestions please

thanks

[oldford]

Try reading the vehicle speed somewhere else: engine, gearbox, instrument panel.
Any fault codes anywhere?

[z786]

no fault codes mate, iv tried evrywhere esle for mileage reading and i can get any, only rpm data.
, mph i can only get from ABS

[Liteace]

Hi, i have a passat here, TDI, The MPH needle does not go above 30MPH no matter what speed you do, ABS sensor readings seem to be fine but cant check them above 24km/h because abs module locks out due to safety

the mileage does not go up as normal, eg a 40 mile journey wil clock maybe 12 miles

anybody got suggestions please

thanks

Dont hold me to this cause I cant remember BUT I think I read somewhere a long time ago (or maybe I was dreaming) that someone had a similar problem and it was to do with the resistance of the brake light bulbs !!!!!!!!!!!!!

[z786]

Dont hold me to this cause I cant remember BUT I think I read somewhere a long time ago (or maybe I was dreaming) that someone had a similar problem and it was to do with the resistance of the brake light bulbs !!!!!!!!!!!!!

nope, you wasnt dreaming

http://www.digital-kaos.co.uk/forums...2005-a-160758/

i'l have a check

[Meat-Head]

24km/h because abs module locks out due to safety

eg a 40 mile journey wil clock maybe 12 miles

anybody got suggestions please

so if you do 20km/h for one hour (whatever that is in Inglish) does it add
"20 km" to the MILES?

1) can you download an ossisyscope and drive/slow frame down.

2) see if the wiring is rotten b abs?

3) unplug each sensor one at a time, see if just one sensor is driving the speedo - only go slow

4) as it is, if you do 150 MPH and slam the anchers on as hard as you can
do you crash, shit yourself or abs work?

[Liteace]

3) unplug each sensor one at a time, see if just one sensor is driving the speedo - only go slow

Dont these new ~~~~ing stupid all electronic crap cars read all 4 wheels then the ABS ECU works out the speed

[Meat-Head]

Dont these new ~~~~ing stupid all electronic crap cars read all 4 wheels then the ABS ECU works out the speed

pass, in that case it would suggest the car is ~~~~ed, you need a new one.

Does the engine ecu show miles. Then again drive at 20KM/h for 1 hour see if that is incorrect.

can your autoboss do a gauge check?
auto or manwell?

[teuton]

Hi, i have a passat here, TDI, The MPH needle does not go above 30MPH no matter what speed you do, ABS sensor readings seem to be fine but cant check them above 24km/h because abs module locks out due to safety

the mileage does not go up as normal, eg a 40 mile journey wil clock maybe 12 miles

anybody got suggestions please

thanks

Hi M8,

did you check the vehicle speed sensor? Had a couple of different vw models with same fault. the sensor should be
on the tranny.

[Meat-Head]

the sensor should be
on the tranny.

21st centuary technology - expect to be off abs - if has sender then *THINK* it's white/blue wire

[super jumbe]

The Passat has a wheel speed sensor in the front and the rear. The position of the wheel speed sensor determines where you place the jack.

The anti-lock brake system on the Passat helps improves the ability of the car to stop quickly without locking the brakes. In an anti-lock system, the wheel speed sensor calculates the speed of the wheels by determining how quickly the wheel completes a full rotation.

I have always taken out old speed sensors and cleaned then with wire brush and most of them worked perfect.

[raf0468]

[QUOTE=Liteace;1004294]Dont hold me to this cause I cant remember BUT I think I read somewhere a long time ago (or maybe I was dreaming) that someone had a similar problem and it was to do with the resistance of the brake light bulbs !!!!!!!!!!!!![/QUOT

that was the findings from customer feedback for the astra h...
for your problem on passat if its still the same as the 2000 model ,speed sensor on the gearbox in engine bay....
had a faulty one customer drove car to me it was working had speedo adjusted and drove home, rings back no speedo and miliage not running up, after investigating lose plug on speedo sensor, later admits had an engine change and car just came out of workshop.......

[digi-dash]

this car HAS a vss in gearbox. the fault you have is caused by the vss drive cog in the box will be at fault or if your lucky the vss. remove vss and move car to turn cog and look for missing teeth or damage, regards steve

[Meat-Head]

remove vss and move car to turn cog and look for missing teeth or damage, regards steve

if you are unable to find any damage, jamb a screwdriver down the hole and give it a wiggle

[teuton]

Hi z786,

what is the outcome of this one?