2009 fiesta zetec s 1.6 petrol

[Archiedeemis]

Hi guys 👋 I have a 2009 fiesta zetec s 1.6 petrol and my electric power steering and rev counter are not working and engine management light is on.
Iv replaced the battery, and crank sensor, as their was a fault code on forscan when plugged in on laptop for the crank sensor ( sorry I can't remember the code🙈🙈) there was also a DTC code U0401- invalid data ŕecieved from engine control module.
-no symtoms
-intermittant.

that was 4 days ago and all was great, the car never missed a beat. It is intermittent 100% as when outside temps are above 15 degrees or warm ish it will start and drive perfect everything works fine 🤷‍♂️🤷‍♂️ but this morning I got up and it was raining and 12 degrees outside and my heart sank as I knew the electric steering wasn't going to co operate and sure enough started the car and the steering was rock solid with power steering light on,the rev counter stopped working with engine management light on aswell.
Please help folks any advise will be very much appreciated 🙏

 

[Archiedeemis]

I forgot to mention the loss of power when the rev counter stops working 🙈 this was why I replaced the crank sensor 4 days ago.thought that fixed it but no luck lol thanks folks😁👍

 

[Archiedeemis]

Iv just been out to the car and wiggled the wire from the crank sensor up the harness to the connector (roughly sits in between the drivers headlight and altonator) wires look fine no splits or brakes and pins look in good condition, start the car power steering works with the eps light out now but still no rev counter and management light is still on drove the car no issues at all apart from having no rev counter and a little loss of power.
Switched engine off and Went into the house for a brew went back out to see if all was still OK and eps solid again🙈🙈

 

[Handy Andy]

Lot of times, when you wiggle a connector, that's fine, but in many cases the connector BODY can mate to offer a tight seal...

But the ELECTRICAL connections within it - are not making complete and constant contact.

So that means you'll have to investigate and do some minor surgery on the contacts.

Nothing big, (use caution though for it can become one big Mess) just a careful use of a pick or awl and strong glasses, to reform or reshape the OLD connector side to fit the new connector side.

IN some instances - why old? Well, due to the sizing on the new connector those wires and connector tab points are of a different size - of standard pin, but the OLD pins used the OLD connector size so they need to be refitted to re-establish reliable connections.

This problems is similar to when you have an old lamp for the headlight, you swap out the old headlight only to find the bulb now works, when it wants to. This indicates the connector is ok, but the connection is not - usually you'll have to re-bend the tabs on the old socket so the new one on the bulb can firmly press-fit it.

 

[Archiedeemis]

Lot of times, when you wiggle a connector, that's fine, but in many cases the connector BODY can mate to offer a tight seal...

But the ELECTRICAL connections within it - are not making complete and constant contact.

So that means you'll have to investigate and do some minor surgery on the contacts.

Nothing big, (use caution though for it can become one big Mess) just a careful use of a pick or awl and strong glasses, to reform or reshape the OLD connector side to fit the new connector side.

IN some instances - why old? Well, due to the sizing on the new connector those wires and connector tab points are of a different size - of standard pin, but the OLD pins used the OLD connector size so they need to be refitted to re-establish reliable connections.

This problems is similar to when you have an old lamp for the headlight, you swap out the old headlight only to find the bulb now works, when it wants to. This indicates the connector is ok, but the connection is not - usually you'll have to re-bend the tabs on the old socket so the new one on the bulb can firmly press-fit it.

 

[Archiedeemis]

Hi andy😁 thanks for taking time to reply👍👍I am taking the car to my mechanic again today and dropping it off as I'm away for 10 days. I'll show him the reply you sent to me and get him to investigate all connections, wires and plugs👍👍
Can I ask what would be the likely cause of the problem? When my electric steering does decide to work, the rev counter also starts working again and the engine management light will go out and the car doesn't run rich or lumpy anymore while restoring all power to the engine🤷‍♂️🤷‍♂️ also why does the change in weather ie hotter or colder make a difference as to wether everything work or not?
Again thanks for your time, stuart😁

 

[Handy Andy]

IT's when one connector mates with another - when they are all the same - over time they develop a memory of the contact points - even when the seal and vibration outside doesn't change their "aspect" or orientation - but the SURFACES that make the connection point for electrical - are the ones that develop the tensile memory and can forget to "spring back" to original shape - it needs a little help by re-bending so the tensile hold and connection can be made.

So when the new connector side is tried to mate with the other - the plastic tabs can align and even the electrical can be made, but remember the older connection side developed the memory of the other mated partner - now separated - different broken, and you're trying to put a new one on - it's not exactly the same fitment - even though most other indices show it works, the intermittent results of the connection are what is telling me the old connector and the new replacement are not getting along.

Why? The old one has developed a memory of the other mated partner - hence the issues of point contacts.

It is exacerbated and the connection is deprecated, with acceleration, when heat and environmental impacts of the elements are added in.