Technical Multiple earthing type issues low fuel pressure random failure help please!

[wad2502]

Fiat Tipo Easy + Multijet 120 start / Stop 2019 32,000 miles.
issues
Lights up like a Christmas tree. Tyre pressure, ABS failure, Engine failure, Low fuel pressure, Start / Stop disabled.
Codes
P0087 over and under pressure
P025B-00
B1029-64
U1001-87-C2-Can
C1221-86
C-130-86
and more
Sometimes fails to start when warm with Start / Stop but starts on key.
Sometimes will not start on Key, hot or cold.
Tried both keys same result so unlikely to be key / security problem?

Fitted new earth leads from battery to engine and Car frame on top of existing earth cluster of connectors.

Still doing it.

Can be running on tick over and just stop randomly, and can do this while driving also... not good.. we have the stupid dangerous 4 lane no hard shoulder M6 around where I live. When error code not cleared (sometimes it is only P0087 low fuel pressure) the engine runs rough and occasionally rattles for a second or two (not extreme) before running smooth again.

So where the hell do I start?

Battery is the correct spec and new.

ODB port loose and hanging down so looks like someone has had a lot of go's at it before selling it.
Bought from a Car Supermarket so no warrantee worth paper it is written on.
Any idea where to start on this one?
Had it recovered to a mechanic who put the key in and it started 1st time after 4 days of refusing to start, no error codes were showing when he checked it.
I had cleared the codes but it still refused to start left it 4 days before it was towed then it started 1st time..
My suspicion is it is an earthing issue but having already put cables from Neg battery terminal to a good earth on the engine and also to the car frame.. where else might the earth break be taking effect?
I am going to disconnect the cluster of earth leads on the frame of the car and check each cable to earth or for continuity I cannot think what else to try?

 

[chris3234]

Any signs of water ingress in the fuses boxes?

And green terminals or anything like that?
Not that I recall seeing any evidence of any such issues in the Tipo

Give the main wiring loom a wiggle as much as you can around the ECU under the bonnet while the engine is running see if you get anything happen

 

[Barkydog]

Are you sure the battery is ok? When battery is faulty or low it nearly always throws loads of warning lights like these. I had it on a 500X and on my Tipo. First time it was a dead cell second time on Tipo low battery. If not possible faulty ECU?

 

[wad2502]

Are you sure the battery is ok? When battery is faulty or low it nearly always throws loads of warning lights like these. I had it on a 500X and on my Tipo. First time it was a dead cell second time on Tipo low battery. If not possible faulty ECU?

It is a new RAC battery. the car is ex Motability and they sort out all the breakdown problems. I have watched the vehicle fail to restart and the voltage never drops below 11.7 volts on cranking which is good. that side looks fine. I checked the resistance to earth and found even with my two added pure copper earth straps added it was still 0.021 Ohms. So I striped it all off and had another go and now have the resistance down to 0.001 Ohms Which is as low as my meter will measure. So maybe I have cured that issue time will tell.

 

[wad2502]

Any signs of water ingress in the fuses boxes?

And green terminals or anything like that?
Not that I recall seeing any evidence of any such issues in the Tipo

Give the main wiring loom a wiggle as much as you can around the ECU under the bonnet while the engine is running see if you get anything happen

No none, the vehicle looks damn near brand new under the bonnet. Clearly someone has had the connector to the ABS sensor off at some time. The factory locking black cable tie is missing on two connectors that one and the loom to the top of the engine.

 

[wad2502]

Fiat Tipo Easy + Multijet 120 start / Stop 2019 32,000 miles.
issues
Lights up like a Christmas tree. Tyre pressure, ABS failure, Engine failure, Low fuel pressure, Start / Stop disabled.
Codes
P0087 over and under pressure
P025B-00
B1029-64
U1001-87-C2-Can
C1221-86
C-130-86
and more
Sometimes fails to start when warm with Start / Stop but starts on key.
Sometimes will not start on Key, hot or cold.
Tried both keys same result so unlikely to be key / security problem?

Fitted new earth leads from battery to engine and Car frame on top of existing earth cluster of connectors.

Still doing it.

Can be running on tick over and just stop randomly, and can do this while driving also... not good.. we have the stupid dangerous 4 lane no hard shoulder M6 around where I live. When error code not cleared (sometimes it is only P0087 low fuel pressure) the engine runs rough and occasionally rattles for a second or two (not extreme) before running smooth again.

So where the hell do I start?

Battery is the correct spec and new.

ODB port loose and hanging down so looks like someone has had a lot of go's at it before selling it.
Bought from a Car Supermarket so no warrantee worth paper it is written on.
Any idea where to start on this one?
Had it recovered to a mechanic who put the key in and it started 1st time after 4 days of refusing to start, no error codes were showing when he checked it.
I had cleared the codes but it still refused to start left it 4 days before it was towed then it started 1st time..
My suspicion is it is an earthing issue but having already put cables from Neg battery terminal to a good earth on the engine and also to the car frame.. where else might the earth break be taking effect?
I am going to disconnect the cluster of earth leads on the frame of the car and check each cable to earth or for continuity I cannot think what else to try?

Update. Took it for a short test drive after clearing the codes. It behaved fine until I got back and the stop start kicked in. I put my foot on the clutch to restart the engine and it took 7 or 8 revolutions before it started. I was looking at the data stream and the pressure on the pump stayed low (16 to 32 Bar) then shot up to 189 and 400 bar when it started and settled down to 250'ish bar (240 / 254 bar) after ticking over for a min or two the pressure started osculating up and down a bit then it cut out. After showing a 180'ish Bar. It then restarted perfectly and stayed working on tick over. I then ran out of time today to dig any deeper. I got no error codes today from it cutting out which is very strange.

 

[wad2502]

Any signs of water ingress in the fuses boxes?

And green terminals or anything like that?
Not that I recall seeing any evidence of any such issues in the Tipo

Give the main wiring loom a wiggle as much as you can around the ECU under the bonnet while the engine is running see if you get anything happen

I will try shaking the connectors and the ECU to see if there is any problems there. Someone has had the fuse box under the bonnet out at some time in the past. I unbolted it and had a look for burnt wires of anything that looked like it has been getting hot. It all looked brand new. the connectors (two of them) that go onto the main ECU at the back of the engine compartment have both still got their cable ties on so have never been disturbed from new. I suspect these issues have been on this car from new.

 

[wad2502]

Fiat Tipo Easy + Multijet 120 start / Stop 2019 32,000 miles.
issues
Lights up like a Christmas tree. Tyre pressure, ABS failure, Engine failure, Low fuel pressure, Start / Stop disabled.
Codes
P0087 over and under pressure
P025B-00
B1029-64
U1001-87-C2-Can
C1221-86
C-130-86
and more
Sometimes fails to start when warm with Start / Stop but starts on key.
Sometimes will not start on Key, hot or cold.
Tried both keys same result so unlikely to be key / security problem?

Fitted new earth leads from battery to engine and Car frame on top of existing earth cluster of connectors.

Still doing it.

Can be running on tick over and just stop randomly, and can do this while driving also... not good.. we have the stupid dangerous 4 lane no hard shoulder M6 around where I live. When error code not cleared (sometimes it is only P0087 low fuel pressure) the engine runs rough and occasionally rattles for a second or two (not extreme) before running smooth again.

So where the hell do I start?

Battery is the correct spec and new.

ODB port loose and hanging down so looks like someone has had a lot of go's at it before selling it.
Bought from a Car Supermarket so no warrantee worth paper it is written on.
Any idea where to start on this one?
Had it recovered to a mechanic who put the key in and it started 1st time after 4 days of refusing to start, no error codes were showing when he checked it.
I had cleared the codes but it still refused to start left it 4 days before it was towed then it started 1st time..
My suspicion is it is an earthing issue but having already put cables from Neg battery terminal to a good earth on the engine and also to the car frame.. where else might the earth break be taking effect?
I am going to disconnect the cluster of earth leads on the frame of the car and check each cable to earth or for continuity I cannot think what else to try?

OK I took the vehicle to BS Mason in Newcastle under Lyme. They have diagnosed the problem having recently seen exactly the same sort of error codes on another vehicle. After 2 weeks they got help from Fiat themselves who pointed to the wiring loom under the rear seat. The problem is the electric fuel pump going high resistance and drawing too much current which burns out the wiring loom. So the fix they think is to replace the wiring loom and the fuel pump. They tried just replacing the loom on the other car and it burnt out again in short order. It will cost me £700+ but should be sorted.