Ducato speedo (1 Viewer)

[mickyb]

Can anyone shine any light on a problem with my 2003 swift sundance (ducato based) speedo fault. When starting engine from cold & running at idle with vehicle stationary, the speedo fluctuates anywhere between 0-80mph as soon as I touch the throttle speedo returns to zero. Then when I start to move even just creeping from rest the speedo goes haywire fluctuating as above then after a couple of miles all seems to settle down to normal, no other gauges i.e fuel,temp & rev counter are not affected & all read normally, the only thing that has occured at the same time & has only happened once is no engine speed response to throttle pedal position. I have read threads where the speedo doesn't register at all for a few miles, the part at fault for this syptom seems to point to a fault with the speed sensor in the gearbox.

 

[hilldweller]

I have read threads where the speedo doesn't register at all for a few miles, the part at fault for this syptom seems to point to a fault with the speed sensor in the gearbox.

I've read of cases of a nylon gear failing due to water getting into the gearbox oil from a drain for the scuttle. Bad news, it was an expensive fix. I had my gearbox oil checked to be sure.

 

[pappajohn]

not helpful at all but guaranteed to work

tape a beermat over the speedo and drive at the same speed as everyone else:Blush:

 

[sinbad1]

take your time and use satnav

 

[scotjimland]

Doesn't sound like a mechanical drive.. of course I may be wrong , but I had the same problem on my RV. , speedo was all over the place and didn't work occasionally, all down to a dirty connection at the speed sensor .. worth checking.

 

[tucker_j]

Ours did that too

When I collected our 2008 CI based on a Fiat from the dealer the speedo did exactly what you describe. About 3 miles into the journey under braking it suddenly settled down. I put this down to the fact the vehicle had been standing at the dealers for some time before we brought it.

Unfortunately I haven't driven it since :Blush:, but will be venturing out this Friday so will find out then if my theory is correct or not.

When I was speaking to Fiat about another matter I mentioned this to them, the guy said the speedo receives the information electronically from a sender and although he wasn't aware of an issue it was a relatively simple problem to fix.

I am aware of three such occurances of this fault, including mine. If it is still doing it on Friday I'll be phoning Fiat on Monday as luckily it is still under warranty.

 

[mickyb]

Thanks to everyone who replied, after checking wiring,fuses and much scratching of the head I took the plunge and purchaced anew speed sensor unit from Fiat it cost 61 pounds,ouch!!. very easy to replace just raised o/s/f, using axle stand of course, and crawled underneath sensor sited on differential housing where o/s drive shaft enters and is held in by one bolt,new one fitted and hey presto speedo works again.

 

[Baker69]

The older Fiat Ducato's have a speedometer cable which I assume is worm driven from the gearbox, i.e. does not have a sender unit.

My Swift Royale has a very erratic speedometer needle and it is constantly jumping +/- 10mph over/under. I know for a fact that it has had a new speedometer cable fitted about a year ago which was professionally fitted. Has anyone else experienced problems with these older Fiats, is it a cable problem? The only time I've come across this sort of sympton before was on a motorcycle and the cable which wasn't properly seated in the speedo head.

 

[Wall-E]

Hi Baker69,
Your speedo will be work via a couple of nylon cogs that are on one of the drive shafts where the cable enters the gearbox. one of these nylon cogs has some long pawls on it that get misplaced at times and causes the speedo to throw a tantrum.
A cure that I know to work is this, but with safety in mind needs a garage hoist. Raise the van. drain the gearbox oil, remove the gear box end plate, you will now be able to see the cogs and the indentations in the shaft that the pawl ends fit into. check that neither cog is damaged, if OK, put all the pawls in position and place a suitable CABLE TIE around the shaft and pawls and pull TIGHT to keep them there, cut off any surplus (Leave a bit sticking out). check again everything is in position. replace the end plate (Gasket?) and refill with NEW gearbox oil. If the cogs are damaged the drive shaft will have be removed to get the cogs out and will need some new drive shaft seals. but it is normally it's only the pawls becoming misplaced that is the problem. an hour or so work?. Not a lot of people know this!!.
Wall-E.

 

[Baker69]

Hi Baker69,
Your speedo will be work via a couple of nylon cogs that are on one of the drive shafts where the cable enters the gearbox. one of these nylon cogs has some long pawls on it that get misplaced at times and causes the speedo to throw a tantrum.
A cure that I know to work is this, but with safety in mind needs a garage hoist. Raise the van. drain the gearbox oil, remove the gear box end plate, you will now be able to see the cogs and the indentations in the shaft that the pawl ends fit into. check that neither cog is damaged, if OK, put all the pawls in position and place a suitable CABLE TIE around the shaft and pawls and pull TIGHT to keep them there, cut off any surplus (Leave a bit sticking out). check again everything is in position. replace the end plate (Gasket?) and refill with NEW gearbox oil. If the cogs are damaged the drive shaft will have be removed to get the cogs out and will need some new drive shaft seals. but it is normally it's only the pawls becoming misplaced that is the problem. an hour or so work?. Not a lot of people know this!!.
Wall-E.

Thanks Wall-E for your advice.

We don't have access to these sort of facilities at home unfortunately so it looks like a garage job (unless we put up with the fluctuating speedo needle!) :Sad:

With safety in mind, could the job be done from ramps or do you need to get unhindered access from underneath the vehicle?

 

[bikerman0346]

Can anyone shine any light on a problem with my 2003 swift sundance (ducato based) speedo fault. When starting engine from cold & running at idle with vehicle stationary, the speedo fluctuates anywhere between 0-80mph as soon as I touch the throttle speedo returns to zero. Then when I start to move even just creeping from rest the speedo goes haywire fluctuating as above then after a couple of miles all seems to settle down to normal, no other gauges i.e fuel,temp & rev counter are not affected & all read normally, the only thing that has occured at the same time & has only happened once is no engine speed response to throttle pedal position. I have read threads where the speedo doesn't register at all for a few miles, the part at fault for this syptom seems to point to a fault with the speed sensor in the gearbox.

Hi Ihave a 2006 Ducato lagan. The rev counter failed completely, took a chance and got a risky cheap replacement for under £7 . I know you shouldn't but it worked and made a big saving. You could consider it just to see if it cures it. I don't think its difficult to fit .
Cheers Mike Plymouth

 

[bikerman0346]

Can anyone shine any light on a problem with my 2003 swift sundance (ducato based) speedo fault. When starting engine from cold & running at idle with vehicle stationary, the speedo fluctuates anywhere between 0-80mph as soon as I touch the throttle speedo returns to zero. Then when I start to move even just creeping from rest the speedo goes haywire fluctuating as above then after a couple of miles all seems to settle down to normal, no other gauges i.e fuel,temp & rev counter are not affected & all read normally, the only thing that has occured at the same time & has only happened once is no engine speed response to throttle pedal position. I have read threads where the speedo doesn't register at all for a few miles, the part at fault for this syptom seems to point to a fault with the speed sensor in the gearbox.

Hi mine stopped working completely. Bought a replacement for under £7 on Amazon, not usually recommended I know but it worked for me with massive saving on genuine. It could be worth a try with little outlay to see if this cures it ? I didn't fit mine but the mechanic said it's not difficult.

 

[peterc10]

The thread is 12 years old. I suspect he will have sorted it by now