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        General >> Problems >> Is this a VSS problem?
        
(Message started by: burmesepython on Apr 7^th, 2005, 9:00pm)

Title: Is this a VSS problem?
Post by burmesepython on Apr 7^th, 2005, 9:00pm

Hi,

The car is 95 2.9 12v ultima, the problems - many.

When it is cold - no problem.

But as soon as it warms up - idle gets erratic. As it gets hotter, speedo starts understating speed (changed instrument cluster - the same), gearbox won't change into top until 3500 revs (speedo says 40mph - real speed more like 70mph), stereo volume erratic, heater starts going cold then hot.

I'm leaning towards VSS, but would that account for all this?

Cheers,
Adam..

Title: Re: Is this a VSS problem?
Post by scorpio_man on Apr 7^th, 2005, 9:19pm

hi there

could be. everything you've said is connected. do an instrument reset and see what speed the vss is outputting http://www.fordscorpio.co.uk/instreset.htm

Title: Re: Is this a VSS problem?
Post by burmesepython on Apr 7^th, 2005, 9:27pm

thx for the tip - will try that out tomorrow

Title: Re: Is this a VSS problem?
Post by burmesepython on Apr 7^th, 2005, 9:52pm

Just did a quick round the block test.
At 25mph on speedo - digital readout says 40 and at speedo 40mph, digital says 60 mph.

Is the changeup on the box triggered by the speedo - not the vss? That is the only way I can think to explain why it does not go into top until speedo say over 40mph - but at this point vss would inducate over 60

Cheers,
Adam..

Title: Re: Is this a VSS problem?
Post by Snoopy on Apr 7^th, 2005, 10:34pm

Ther is one other thing to check before going down the route of the VSS .. Under the Idle controlvalve there is a vacum conncetion which does get knoocked off sometimesand if its disconected the ger changes on the 12 v become very erratic and the idle is awful. Otherwise clean the icv and then change the vss if all else fails.

Title: Re: Is this a VSS problem?
Post by Eric_R on Apr 8^th, 2005, 8:20pm

Adam,
Yes, the VSS signal is used by the Powertrain Control Module (EECIV on yours) to change into 3rd and Top - and it is used by the radio when the Automatic Volume Control is selected, and also by the steering rack where you have a speed-sensitive steering option.

From your description the VSS is certainly suspect - the manual is at http://www.fordscorpio.co.uk/manual/electrical/intbasic/VSS.pdf

Changing it is quite a simple job.