Speed incorrect on speedometer

[Deanojones]

Is the bus a rwd 5 speed ?
Not the tdci with 6 speed?
Or a 5 speed originally,with a 6 speed fitted ?

If it’s all the same drivetrain as it left factory
The PCM is going to be the issue,it’s either got the wrong software completely,or the axle ratio / tyre size setting configuration is wrong for that vehicle
You need someone who knows what they are doing with a laptop.

If it was a 5 speed from factory,and someone’s converted it to 6 speed you may have same issue.

5 speed rwd all same as left factory, as stated in original post that I put a snippet from previous owner he changed fuel pump and had ecu sent off

The speedo originally worked so it’s not a diff change or anything like that.

Not long after I purchased the van it would only fire up intermittently so I spoke to the guy I bought it from and he’d had issues with a fuel pump sensor before and a company called autotronics had fixed it.

So I sent it there and it didn’t resolve.

I then tested a different ecu and that didn’t fix it either

Finally I purchased a reconditioned fuel pump (about £900!) and used the reconditioned pump sensor and while it worked fine since then the speedo was out.

I then sent the pump, sensor and ecu back to autotronics and they were sh*t and as I’d already spent a fortune on the pump, the work to be done and a recon ecu thought I’d live with the speedo

[Frag]

If it’s all the same drivetrain as it left factory
The PCM is going to be the issue,it’s either got the wrong software completely,or the axle ratio / tyre size setting configuration is wrong for that vehicle
You need someone who knows what they are doing with a laptop.

[Deanojones]

If it’s all the same drivetrain as it left factory
The PCM is going to be the issue,it’s either got the wrong software completely,or the axle ratio / tyre size setting configuration is wrong for that vehicle
You need someone who knows what they are doing with a laptop.

Thankyou

[Deanojones]

If it’s all the same drivetrain as it left factory
The PCM is going to be the issue,it’s either got the wrong software completely,or the axle ratio / tyre size setting configuration is wrong for that vehicle
You need someone who knows what they are doing with a laptop.

Thankyou

Got a friend coming tomorrow with his forscan, but today iv received a message from a guy from canada saying he can fix it remotly via forescan for £50…. Seems dodgy to me…. When we plug in tomorrow is there anything i can look out for what can help me thanks
Dean

[Frag]

It will be listed in PCM,configuration
Axle ratio / tyre size and when you enter those it will calculate the revs per mile and write it to the pcm
So you do need to know the rear axle / diff ratio………


Also,
In the vans door frame (passenger side usually)
There should be a sticker with a number on it like for example ;
6c11-12k532-hj

This is the pcm software the van left the factory with.
You may have to reflash the PCM with this(or its update) to fix the fault,if changing tyre size and axle ratio does not fix it.

I wouldn’t be happy letting someone do this remotely (from Canada) as he will have to use team viewer or similar and remotely take over the laptop to do this..

If your mate with forscan can’t do it,the man to talk to is vantuner / martynx on here.
He may be able to fix it via the postal service where you send him you ecu
Or you go see him depending where you are in the country

[Deanojones]

It will be listed in PCM,configuration
Axle ratio / tyre size and when you enter those it will calculate the revs per mile and write it to the pcm
So you do need to know the rear axle / diff ratio………


Also,
In the vans door frame (passenger side usually)
There should be a sticker with a number on it like for example ;
6c11-12k532-hj

This is the pcm software the van left the factory with.
You may have to reflash the PCM with this(or its update) to fix the fault,if changing tyre size and axle ratio does not fix it.

I wouldn’t be happy letting someone do this remotely (from Canada) as he will have to use team viewer or similar and remotely take over the laptop to do this..

If your mate with forscan can’t do it,the man to talk to is vantuner / martynx on here.
He may be able to fix it via the postal service where you send him you ecu
Or you go see him depending where you are in the country

Thankyou for your comment, we will have a look tommorow and if no joy il try find someone local to Hull or East yorkshire to try fix it, iv asked about 30 mechanics/technicians and they all seem confused and cant commit to fixing it

Thanks

Dean

[Deanojones]

Sorry to be a pain but where would I find the rear diff ratio please?

It will be listed in PCM,configuration
Axle ratio / tyre size and when you enter those it will calculate the revs per mile and write it to the pcm
So you do need to know the rear axle / diff ratio………


Also,
In the vans door frame (passenger side usually)
There should be a sticker with a number on it like for example ;
6c11-12k532-hj

This is the pcm software the van left the factory with.
You may have to reflash the PCM with this(or its update) to fix the fault,if changing tyre size and axle ratio does not fix it.

I wouldn’t be happy letting someone do this remotely (from Canada) as he will have to use team viewer or similar and remotely take over the laptop to do this..

If your mate with forscan can’t do it,the man to talk to is vantuner / martynx on here.
He may be able to fix it via the postal service where you send him you ecu
Or you go see him depending where you are in the country

[dumper]

On older transits they used to have a tag on the diff pan cover or the ring of bolts that hold diff unit in axle tube depending on type

[knobby1]

Sorry to be a pain but where would I find the rear diff ratio please?

Unless you have a TDCi 6 speed or a tipper, recovery, motor home or a Dana type dual wheel axle you'll have only one of 3 ratios, 3.63:1, 5.13:1 & 5.14:1.

What rpm are you doing at ~60mph.?? That will give you the answer.

Lord Knobrot (Smithy)

[Deanojones]

Sorry to be a pain but where would I find the rear diff ratio please?

Unless you have a TDCi 6 speed or a tipper, recovery, motor home or a Dana type dual wheel axle you'll have only one of 3 ratios, 3.63:1, 5.13:1 & 5.14:1.

What rpm are you doing at ~60mph.?? That will give you the answer.

Lord Knobrot (Smithy)

Found the tag, was a bit rusty but identified a 5,3 and a 1so looks like a 5:13:1
We plugged the forscan in but couldnt identify where to look for ratio settings on there, had it plugged in and went for a drive as we thought its possibly set up in kph not mph but still showed 50mph on forscan when doing 20mph, il try get it booked in somewere but struggling to find anyone local where i can take it.
Thanks for your help, im determined to get it fixed before i head for spain in august

[metalworker0]

if forscan can read the speed .. then not at all the set up i thought it had .. as things have to go digital for forscan to read it, its just the drum type mileage counter that made me think it was all analogue.

all the best.mark