Well a week after having the rear wheel bearing replaced I was driving to work last nite when as i went round a bend I got a beep "engine system failure" " acceleration limited" " speed limited" and the rev counter and speedo were going from 30 to 0 then back to 30 rev counter doing the same I pulled over switched off and on and all okay on the dad test I get d900 as the dtc plugged in my code reader no codes found I've ran a few checks and still no codes only those stored on the dash test any ideas guys it so far touch wood hasn't done it since

What code reader you using? Does it do abs dtcs?

A memoscan it does all codes used it on mums Citroen my sisters old Citroen and the fiesta focus and Vauxhall

Thats a good reader then if it does, may be coincidence with wheel bearing, if sensor or wiring to wheel bearing was at fault them im sure an abs dtc would trigger.

My memoscan does all cars but only pcm and tcm dtcs.

I would touch wood a bit more often.

Not something ive come across.

Well a week after having the rear wheel bearing replaced I was driving to work last nite when as i went round a bend I got a beep "engine system failure" " acceleration limited" " speed limited" and the rev counter and speedo were going from 30 to 0 then back to 30 rev counter doing the same I pulled over switched off and on and all okay on the dad test I get d900 as the dtc plugged in my code reader no codes found I've ran a few checks and still no codes only those stored on the dash test any ideas guys it so far touch wood hasn't done it since

I had this problem last year and you waxed lyrical about how it was the Ti-VCT and would cost £100s to replace! :-)

But anyway, this time last year, I started to get intermittent limp modes, no codes, had plugs and coil pack changed, came back a few weeks later. Threw up a code of pedal sensor, had this changed, then it came back again, so I took it too a electric specialist who diagnosed it was a problem with the loom into the coil pack, as Ford make the wires too short so it wasn't connecting properly. They made me a new one (ford charge £400!) and it hasn't missed a beat since.

I'll also say the engine became very sluggish and started misfiring after a while too. If the problem persists I'd definitely look at this possibility before throwing money at it.

Ti vct unit was all replaced no misfires car runs as it should apart from the weird fault coil and leads were new last year ford ones checked everything I can think of ill have to wait and see I it reoccurs and grab the code

Ti vct unit was all replaced no misfires car runs as it should apart from the weird fault coil and leads were new last year ford ones checked everything I can think of ill have to wait and see I it reoccurs and grab the code

But with mine it didn't give the right code, only false ones, which I had the garage sort, cost me a lot of money for nothing. There won't be a code to tell you the connector between the loom and the coil pack is loose. Take it to an autoelectrician, apparently it is a common problem on Fords and the misfires started a month after the first limp mode. My engine is the same as yours BTW.

Next to the generic DTC codes (descibed by European law) that can be read with any OBD code reader Ford also uses manufacturer specific DTC codes. Many universal code readers do not read/display the Ford specific DTC codes.

The best way to diagnose a Ford is by using a Ford specific diagnostic system. I have the original Ford IDS diagnostic system and the FoCom (Ford specific) diagnostic system and both systems read/display DTC codes that are not read/displayed by universal diagnostic systems.

d900 is a can comms issue which is all ive got when or if it happens again ill get the code my mistake was to switch the engine off then on which cleared the fault just never seen the rev counter and speedo bounce up and down like that at the same time

well ive got to the bottom of the issue and frankly you wont believe it

i stated the rear hub and bearing had been replaced well i kept getting the engine management light after cornering always high speed can fault and my tracking has suddenly gone out of alignment so today after i got home i got under the car to find that the torq bolts that hold the hub on are all loose the mechanic hadnt tightened them up ive only been driving along twisty roads at 60mph in it when i say loose finger tight one so loose its about 1mm of thread showing so clearly as im cornering the hub is moving throwing up the code oh and all the wheel bolts were put in but none were tight i could put two turns on them to tighten them up the code was d900 dash and u0001 on the reader ill be heading to the garage tomorrow yes ill have to drive as ive got work tonight

It has always amazed me how those 4 fasteners hold the stub axle to the hub carrier and all the loads they have to withstand.

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an update the manager just called on a sunday i know and claims that the hub bolts as they are the original have stretched and he was present when they were torqued up however they will order in new bolts tomorrow morning plug the diagnostics in clear all the codes etc and throw in a free service apparently its common on mondeos but he states that from now on they will refuse to do rear bearings unless all the hub bolts are replaced as well and my trackings out as the hub isnt sitting correctly on the rear

Did your car have the old type of bolts with an internal Torx head or the new type of bolts with an external Torx head?

Ford prescribes not to use the old type of bolts anymore. If the wheel hubs are replaced and the car still has the old type of bolts they must be replaced by the new type of bolts. if the car already has the new type of bolts they can be reused without any problem.

To prevent the wheel hub bolts from coming loose they must be installed with Loctite. On a new car the wheel hub bolts are also installed with Loctite. I installed dozens of these wheel hubs this way and never have seen any of them coming loose.

Personally I doubt the loose wheel hub being the cause of the "Engine System Failure" warning message. The wheel hub does only have an ABS sensor inside. A loose wheel hub does not affect the ABS sensor position in relation to the magnetic sensor ring so there should be no ABS fault as long as the wiring is not broken. Next to this a problem with an ABS sensor will activate the ABS warning light and no engine system failure.

The old type of bolts on mine seems stupid it didn't come with new bolts then as for the light its got to be the wheel nothing before the hub change it started at the same time the tracking went out which is when the rear hub has shifted and only comes on if I corner the car once cleared the car is perfect again

well all bolts replaced and its fine done 400 miles no issues no lights or faults