Live data logging - which parameters to monitor?
Discussion
I have a virtually new Ford Fiesta ST which has suddenly shut down the engine twice when the car is moving. The car re-starts and drives fine and no fault codes are present.
Can anyone suggest which parameters I should log to try to diagnose the cause? I have the FORScan Ford compatible diagnostic tool.
Thanks.
Can anyone suggest which parameters I should log to try to diagnose the cause? I have the FORScan Ford compatible diagnostic tool.
Thanks.
stevieturbo said:
If it's virtually new, then it's under warranty so datalog it right down to the dealers
I bought the car from one of the major car supermarket chains. It turns out the car was rejected by the original owner when it was a few days old. The big mistake I made when I bought it knowing it was pre-owned was to assume that the manufacturer's warranty would cover any issues but Ford can't find any fault codes and have washed their hands of the problem. My legal recourse is with the dealer I bought it from but they've refused to accept my rejection of the car under the Consumer Rights Act due to lack of evidence of any current fault. I've started the formal legal process against them but my fall back if the legal process stalls is to start driving it again and get my own diagnostic evidence if the fault happens again.
If you bought it on finance engage the finance company immediately, if not, park it on the main access road to the dealer with the biggest sign you can where nobody can get past to enter/leave & they will soon sort it out when they are losing money/customers because of it's position.
DRH986 said:
My legal recourse is with the dealer I bought it from but they've refused to accept my rejection of the car under the Consumer Rights Act due to lack of evidence of any current fault.
That's an unreasonable position. What evidence do they expect of a car occasionally cutting out?Have you looked for an alternative dispute resolution (ADR) scheme? This might be easier than court action.
Gov.uk says: The regulations do require almost all businesses which sell directly to consumers to point the consumer to a certified ADR scheme – where they cannot resolve a dispute in-house – and declare whether or not they intend to use that scheme.
E-bmw said:
If you bought it on finance engage the finance company immediately, if not, park it on the main access road to the dealer with the biggest sign you can where nobody can get past to enter/leave & they will soon sort it out when they are losing money/customers because of it's position.
I didn't finance it but I paid a deposit by credit card so am waiting a decision on a Section 75 claim. Indication so far is that the CC provider is taking the same line as the dealer, i.e. please provide evidence of the fault. The dealer is 180 miles away so the visible protest option is not really practical.
GreenV8S said:
DRH986 said:
My legal recourse is with the dealer I bought it from but they've refused to accept my rejection of the car under the Consumer Rights Act due to lack of evidence of any current fault.
That's an unreasonable position. What evidence do they expect of a car occasionally cutting out?Have you looked for an alternative dispute resolution (ADR) scheme? This might be easier than court action.
Gov.uk says: The regulations do require almost all businesses which sell directly to consumers to point the consumer to a certified ADR scheme – where they cannot resolve a dispute in-house – and declare whether or not they intend to use that scheme.
My preference all along has been to get the problem diagnosed and fixed. I informed the supplying dealer immediately the first time it cut out less than 24 hours after collection but it took my local Ford dealer over 3 weeks to investigate. With hindsight I should have rejected it within their 7 day exchange period but they haven't even offered to extend that period.
I've provided them with written evidence from the AA and the original supplying Ford dealer that the first owner suffered loss of power 13 miles before I bought it and rejected the car to Ford, who changed the brake pedal switch and sold it through trade auction.
If I can do some DIY data logging and get some insight into the cause, I can go back to Ford to get it fixed under manufacturer's warranty or extra evidence to support my rejection of the car.
So any data logging tips welcome!
as no one appears to be answering the question, I'll give it a go.
I'd look at fuel related data, fuel pressure specifically, and also look at fuel trims and any throttle related data. After that I'd look at spark and or injectors.
However if you car is faulting with a complete shut down then it's likely to be fuel cut off, or spark cut off. At a complete guess your ECU has some sort of heat based short in it, that when present (i.e. hot) is cutting the circuits to fuel or spark. But you probably need to send the whole car to either Diagnose Dan or Pine Hollow Autodiagnostics.
I'd look at fuel related data, fuel pressure specifically, and also look at fuel trims and any throttle related data. After that I'd look at spark and or injectors.
However if you car is faulting with a complete shut down then it's likely to be fuel cut off, or spark cut off. At a complete guess your ECU has some sort of heat based short in it, that when present (i.e. hot) is cutting the circuits to fuel or spark. But you probably need to send the whole car to either Diagnose Dan or Pine Hollow Autodiagnostics.
Dynion Araf Uchaf said:
as no one appears to be answering the question, I'll give it a go.
I'd look at fuel related data, fuel pressure specifically, and also look at fuel trims and any throttle related data. After that I'd look at spark and or injectors.
However if you car is faulting with a complete shut down then it's likely to be fuel cut off, or spark cut off. At a complete guess your ECU has some sort of heat based short in it, that when present (i.e. hot) is cutting the circuits to fuel or spark. But you probably need to send the whole car to either Diagnose Dan or Pine Hollow Autodiagnostics.
Yes, complete and sudden shut down with no prior indication of any issue. I've done 350 miles in the car, of which 180 were motorway return journey from collecting the car when it behaved perfectly. The remaining miles all local. Both shut downs have been within 10 minutes of cold start. It then immediately starts and runs fine so I agree, fuel or spark cut off. I'd look at fuel related data, fuel pressure specifically, and also look at fuel trims and any throttle related data. After that I'd look at spark and or injectors.
However if you car is faulting with a complete shut down then it's likely to be fuel cut off, or spark cut off. At a complete guess your ECU has some sort of heat based short in it, that when present (i.e. hot) is cutting the circuits to fuel or spark. But you probably need to send the whole car to either Diagnose Dan or Pine Hollow Autodiagnostics.
I'm wondering which PIDs to keep an eye on that might trigger this. But just logging a shut down, even if the cause is not obvious, will be a start as the push back I'm getting is due to lack of any evidence of a fault. At least that would support my legal case though I'd actually prefer to fix it and keep the car.
Sadly Diagnose Dan and Pine Hollow are a bit too far away!
really your best option is to take the car to your local dealer and pay them some money to do a proper diagnostic. If it does fault everytime, or if you can provide them the details of when it occurs then they should be able to replicate the problem. If so, you won't have to pay for the diagnostic and the repair will be carried out under warranty.
It doesn't matter that you bought it from a car supermarket, the warranty is still valid, but you might have a bit of an effort to get a Ford dealer to look at it.
It doesn't matter that you bought it from a car supermarket, the warranty is still valid, but you might have a bit of an effort to get a Ford dealer to look at it.
Sudden shutdown with no prior warning followed by immediate restart without issue would steer me away from fuel pressure / pump towards an electrical issue.
If the engine ecu is losing power / has an internal issue then nothing will be logged anyway as the logging tool will lose comms.
Could be a plug not properly home, intermittent relay or fuse etc. You may end up rigging led indicators across supplies to see what disappears.
Could also be a faulty ignition key switch (if it isn’t keyless) - do have a heavy bunch of keys hanging from it?
If the engine ecu is losing power / has an internal issue then nothing will be logged anyway as the logging tool will lose comms.
Could be a plug not properly home, intermittent relay or fuse etc. You may end up rigging led indicators across supplies to see what disappears.
Could also be a faulty ignition key switch (if it isn’t keyless) - do have a heavy bunch of keys hanging from it?
So elaborate as to this "sudden shutdown".
Is just an engine stop ? power reduction, or complete vehicle power shutdown, nothing at all works, no lights, no nothing ?
Be specific.
Although from an evidence to a dealer point of view, a simple video of this happening should be sufficient for them to then take it. Along with specifics as to the circumstances as to when it happens.
Is just an engine stop ? power reduction, or complete vehicle power shutdown, nothing at all works, no lights, no nothing ?
Be specific.
Although from an evidence to a dealer point of view, a simple video of this happening should be sufficient for them to then take it. Along with specifics as to the circumstances as to when it happens.
stevieturbo said:
So elaborate as to this "sudden shutdown".
Is just an engine stop ? power reduction, or complete vehicle power shutdown, nothing at all works, no lights, no nothing ?
Be specific.
Although from an evidence to a dealer point of view, a simple video of this happening should be sufficient for them to then take it. Along with specifics as to the circumstances as to when it happens.
temporarily mount a dashcam inside the car watching the dashboard and also showing the view out of a window?Is just an engine stop ? power reduction, or complete vehicle power shutdown, nothing at all works, no lights, no nothing ?
Be specific.
Although from an evidence to a dealer point of view, a simple video of this happening should be sufficient for them to then take it. Along with specifics as to the circumstances as to when it happens.
It's keyless ignition.
It's the engine that has shut down, the other electrics were still working as far as we could tell. Both times with my wife driving (the only 2 times she has driven the car) and me in passenger seat. Most info on the digital dash disappears apart from a central message box stating something like "Engine Shut Down" (I wish I could be more certain about the exact message but both our attention has been on avoiding an accident and restarting the car). There has also been an amber warning light on the dash.
I did a forced engine shut down when driving (press and hold the Stop/Start button) but the dash response was completely different - just like a normal engine shut down.
The first owner called the AA out on the day the car was registered but I don't know what the reason for the call out was. They diagnosed DTC P0504 - brake switch A/B correlation error, and a dash warning light, but brake lights were working. Three days later the AA were called out again, this time due to loss of power but no fault codes were found. The AA recovered the car to the Ford dealer who apparently diagnosed P0504 and replaced the brake pedal switch. The owner rejected the car without driving it again after the switch replacement and I bought it 3 months later with only 13 more miles on it since the AA recovery and switch replacement.
The pedal switch assembly has 2 separate switches - one activates the brake lights via the Body Control Module and also sends a 12V signal to the Powertrain Control Module when brake applied. The other switch connects a separate PCM terminal to earth when brake is not applied (switch closed) and opens when brake applied. I thought I might have found a potential issue when monitoring the brake PIDs in FORScan as only one of the BCM brake PIDs responds when the pedal is operated. The two brake PIDs in PCM don't change state. But unfortunately when I did the same tests on another identical car, that gave the same results as mine.
Checking voltage at the switch pins for the switch connected only to the PCM suggests the switch and wiring are working as expected.
I have set up a dash cam to record the dash display but at the moment on legal advice I haven't driven the car for 2 months due to having formally rejected it. If the legal process stalls, the dash cam and data logging are my fall back.
It's the engine that has shut down, the other electrics were still working as far as we could tell. Both times with my wife driving (the only 2 times she has driven the car) and me in passenger seat. Most info on the digital dash disappears apart from a central message box stating something like "Engine Shut Down" (I wish I could be more certain about the exact message but both our attention has been on avoiding an accident and restarting the car). There has also been an amber warning light on the dash.
I did a forced engine shut down when driving (press and hold the Stop/Start button) but the dash response was completely different - just like a normal engine shut down.
The first owner called the AA out on the day the car was registered but I don't know what the reason for the call out was. They diagnosed DTC P0504 - brake switch A/B correlation error, and a dash warning light, but brake lights were working. Three days later the AA were called out again, this time due to loss of power but no fault codes were found. The AA recovered the car to the Ford dealer who apparently diagnosed P0504 and replaced the brake pedal switch. The owner rejected the car without driving it again after the switch replacement and I bought it 3 months later with only 13 more miles on it since the AA recovery and switch replacement.
The pedal switch assembly has 2 separate switches - one activates the brake lights via the Body Control Module and also sends a 12V signal to the Powertrain Control Module when brake applied. The other switch connects a separate PCM terminal to earth when brake is not applied (switch closed) and opens when brake applied. I thought I might have found a potential issue when monitoring the brake PIDs in FORScan as only one of the BCM brake PIDs responds when the pedal is operated. The two brake PIDs in PCM don't change state. But unfortunately when I did the same tests on another identical car, that gave the same results as mine.
Checking voltage at the switch pins for the switch connected only to the PCM suggests the switch and wiring are working as expected.
I have set up a dash cam to record the dash display but at the moment on legal advice I haven't driven the car for 2 months due to having formally rejected it. If the legal process stalls, the dash cam and data logging are my fall back.
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