I've a Mk7.5 Fiesta ST which I've had since new from April 2015.

Yesterday evening I made a couple of short drives to my local supermarkets. After the second stop I started to head back home when I felt a loss in power and I had to change down gear to get some power/speed back.

A service message came up on the Sync 1.1 display but the power never completely died so I managed to slowly get back home over the last mile or so.

I had bought a FORscan adaptor but had never used it up till now and after plugging it it, I got the P0106:62-6 and P123A:62-6C codes.

Looking online I found that cleaning the MAP/MAF/Boost sensors might be things to check, so after a few YouTube videos, I managed to clean the MAF and Boost sensors with some WD40 specialist contact cleaner. I couldn't get to the MAP sensor underneath so that's still to do/check.

After cleaning the MAF and Boost sensors, I cleared the error log and fired the car up and went for a quick drive around the estate, and so far things appear to be ok. No loss of power, no service warnings, and (only last night) no error codes have returned.

I've got to make a few motorway journeys soon and with this issue, and the age of the car, I wanted to see if it's worth pre-emptively getting things checked/parts replaced sooner rather than later. I dropped into the local Ford garage (which is really close and also allowed me to have another mini test drive) and have left a message with the P fault codes and will wait to get a call back in the week.

Any thoughts or ideas on why things happened as they did and if it's worth pre-emptively replacing the sensors (if it's just a sensor problem) with them coming up to 10 years old. I did for one moment last night also have a low fuel pressure sensor error, but I didn't save that log and accidently cleared it. It never came back before I cleaned the sensors (the others did) so I'm not sure if that was just a one-off with the other apparent issues.

Forscan error log P Codes only.txt

If you have FORScan check the Live Data for the MAP, Boost Pressure Sensor if that Engine has one and the Barometric Pressure if that car has a separate one as well with the Ignition on, they should all be the same as each other and around 100 kPa. 

That would be my starting point and take things from there.

 

Hi @Tizer I'll check in a short while.  As I've only used FORscan since last night, I did see that there was a Live Data option but I didn't have the car running at the time so everything was blank. If I turn the engine on and idle, do I need to enable any settings or should the live data be pre-configured to report back data for the sensors installed?

Hi @Zico assuming you have the Windows version, have a read here  https://forscan.org/documentation_13.html  especially from the Dashboard heading. It is not as complicated as it looks when you actually use it.

In short you need to look for PID's in the PCM. You can do that either by scrolling or using the Search Function, bring them across and press play.

Best to do it with the Engine running unless your Battery is good but the ones I mentioned should be checked with just the Ignition on because if the Engine is running the MAP will be below 100kPa.

The Freeze Frame Data logged the Code at 2000 rpm so maybe something happened at that speed but if the readings without moving are not the same the as each other then one of the Sensors is reading incorrectly.

Hi @Tizer,
To confirm I am using the Windows version of FORscan. Thanks for the pointer on the site, I loaded the page up and read the Dashboard section and hopefully I managed to select the relevant options.

I added the battery state to the list of options and noted that when I turned the ignition on it was ~18% so I decided to take the car for a drive so both check things out and build up a little charge. I managed to get a few miles away from home and started to feel the car acting odd, and it was at the ~2000rpm mark as you mentioned in the earlier log.

Within a few minutes of noticing this, the service warning came on again and so I pulled over. I plugged in FORscan again found new warnings for the Fuel Pressure Regulator P0089:62-64 and Fuel Pump P2636:64-64.  I have attached some logs and snips both before a set off, and after I got the warning back on the dash. I also have the livestream log files and took snips of them.

I also took snips of the Dashboard setup also, both with only the ignition on and engine running.

After Forscan error log fuel pump eng run.txt After Forscan error log fuel pump.txt

The MAP/Boost/Baro codes may have been a red herring. The MAP and Baro with the Ignition on are the same as each other, if the Boost is shown in Psi or kPa as well as Voltage then check that as well.

The Battery State of Charge reading may be a mistake in FORScan, I would be surprised if the car started if the Battery was really that low. You could easily check the resting Voltage to rule out a problem with the Battery. There may also be PID's for Voltage and Module Voltage too.

There does seem to be a problem with the Fuel Pressure. There may be PID's for Fuel Pressure Desired and Actual in FORScan that you can monitor. with something like that you can switch to the Graph view in FORScan to make more sense of things. I don't have any Idea what is wrong though.

As a general rule when Live Monitoring things with FORScan I like to also bring up PID's for VSS (speed), RPM and Accelerator Pedal Position as well so when looking at things afterwards I have an Idea what triggered things. Also if there is an Actual and Desired for anything I would always bring that up too.

Thanks for the help Tizer.

I'll have another check tomorrow and see what other options show up for the dashboard.

I think that the only one that showed up with "boost" in the name is the BAP one that I had added at the top of the list.

As for the battery state, other than the short hops between the two supermarkets the other day (~12 mile round trip) I hadn't driven the car for about a week. It's still on it's original Ford/Varta battery from 2015 so it might be due for a change.

I forgot to add, that when I got back earlier this evening, as I was sat in the parking space with the engine idling for a few minutes while I got some more readings, the engine just stopped without me turning off the ignition. I did turn the engine back on within ~30 seconds and it started up again. I didn't leave it running for too long after that and came back inside.

If it's fuel pump related, having a quick check online appears to show it's going to be ~£300 for the part alone.

Found this on YouTube and will check if this might be what's going on with mine (if it's got the same sensor which I'm guessing it should do):

https://j-w-racing.co.uk/product.php/11818/0/genuine_ford_lowside_fuel_injector_pressure_sensor_mustang_ecoboost_2015_2018

https://whooshmotorsports.com/products/motorcraft-low-side-fuel-pressure-sensor-2014-2019-fiesta-st-free-shipping

 

1 hour ago, Zico said:

Found this on YouTube and will check if this might be what's going on with mine (if it's got the same sensor which I'm guessing it should do):

https://j-w-racing.co.uk/product.php/11818/0/genuine_ford_lowside_fuel_injector_pressure_sensor_mustang_ecoboost_2015_2018

https://whooshmotorsports.com/products/motorcraft-low-side-fuel-pressure-sensor-2014-2019-fiesta-st-free-shipping

 

Good find, hopefully that is what the problem is.

I've been out again and tried doing the same as the video I linked to above. Livestreamed the same items with the engine running and pulled the fuse out. Unlike in the video, my low pressure voltage reading did drop and eventually dropped  to less than 1v before the engine cut off after running out of fuel.  If this was the expected behaviour as seen in the second part of the YouTube video, then I got this first time round, and therefore my issue doesn't appear to be the low pressure sensor by that check.

I've uploaded a few screen shots from earlier, and the livestream files if they can be played back by others.  I'm well beyond my depths (was out of my depth the minute I plugged in FORscan 😄 ) so I'm going to have to rely on a garage diagnosis (I would have to do so for any probably repairs as I'm no mechanic and could only do very basic things if I had guides and the right tools).

Sunday22nd-fuel-01-ig-only.txt Sunday22nd-fuel-02-eng.txt FORscanLiveStreams rename-zip.txt

5 hours ago, Zico said:

and the livestream files if they can be played back by others

As far as I know Livestreams of FORScan data can only be played back via the FORScan programme although a very Tech savvy person may be able to do so.

I have done Screen Records of FORScan data on my Phone App before where I wanted to keep a record outside FORScan.

Well a mini update for now.  Took my car into a local garage for a diagnostic check and after them having it for 4 days, I am no closer to knowing what's wrong. Apparently they couldn't find anything wrong with the codes present. Collected the car earlier today, drove the short distance back to the flat and by the time I literally pulled up to park, the service light came on. Didn't even turn the car off, went back to the garage and they checked the codes again, couldn't see anything different so reset them and that's about all.  They are booked up until 11th November for any proper garage time, so for now I've made a booking, but am still not able to do any proper car journeys without the issue provisionally re-occuring.

I am going to try and get under the car at the weekend to get the MAP sensor off and cleaned, but that is about all that I could do IF that has anything to do with the issue at hand.

I've had a quick search of any specialist ford garages and found one (https://www.brcperformance.co.uk) which are nearby so I might try to contact them and see if they can help.

Out of interest, what codes are you getting now, is it the Boost or Fuel Pressure ones or both?

Not sure at the moment, will have to check a little later.

Forgot to check earlier, but the only error code now showing is:
 

===PCM DTC P123A:62-6C===
Code: P123A - BARO - Turbocharger/Supercharger Boost Sensor 'A' Correlation

Additional Fault Symptom (:62):
 - Signal Compare Failure

Status (-6C):
 - DTC Maturing - Intermittent at Time of Request
 - Malfunction Indicator Lamp is Off for this DTC
 - Test not complete

Module: Powertrain Control Module

 Freeze Frame  #1:
-LOAD: 12.94 % - Calculated Load Value
-ECT: 214 °F - Engine coolant temperature
-RPM: 895 1/min - Engine Revolutions Per Minute
-FUELSYS: OL - Drive  - Fuel System Status (Open/Closed Loop)
===END PCM DTC P123A:62-6C===

 

Took the car for a short drive around the estate for about 10 minutes and the turbo noise isn't "normal" but no service flag came up any time.

Small update (well not so small as it looks like I have written war and peace ).

I took the car to BRC last week who had it for a few days and done a few checks (smoke/leak checks) and a few other things, but they said it was running ok. They changed over a couple of the sensors (I think the boost and map) and the guy I was speaking with on Friday said that the values were slightly different than expected, but both my sensors and the ones they swapped over for testing, seemed to report the same values, and everything appeared to be ok when they test drove the car.

The one thing that I did before I took the car to BRC was that I charged the battery up a night or so beforehand (this was after I had watched/read something where the low battery might have been causing the odd codes to flag up).

Since I picked up the car Friday afternoon, on driving back I had no service warning flash up, and seemingly the car drove as normal (under both normal and enthusiastic driving where I could put my foot down).

Saturday afternoon I swapped out the battery for a new one, making sure that was 100% charged beforehand, and took it for a short but scenic test drive from one side of town and back round, both on the short bit of motorway, dual carriageway and town roads (so I was covering various speeds and driving styles) and again everything seemed to be ok.

I forgot to reset the BMS before taking the test drive, so Saturday evening until this morning, I hooked the battery charger up again to fully charge it, and then reset the BMS.

As I hadn't checked FORscan since I had picked the car up from BRC, I hooked up my laptop and found the following codes were flagged:

Quote

 

===PCM DTC P2636:64-64===
Code: P2636 - Fuel Pump 'B' Low Flow/Performance

Additional Fault Symptom (:64):
 - Signal Plausibility Failure

Status (-64):
 - DTC Maturing - Intermittent at Time of Request
 - Malfunction Indicator Lamp is Off for this DTC
 - Test not complete

Module: Powertrain Control Module

 Freeze Frame  #1:
-LOAD: 11.76 % - Calculated Load Value
-ECT: 135 °F - Engine coolant temperature
-RPM: 1168 1/min - Engine Revolutions Per Minute
-FUELSYS: Closed Loop  - Fuel System Status (Open/Closed Loop)
===END PCM DTC P2636:64-64===

===OBDII DTC P2636-P===
Code: P2636 - Fuel Pump 'B' Low Flow/Performance

Status (-50):
 - Pending - malfunction is expected to be confirmed 

Module: On Board Diagnostic II

===END OBDII DTC P2636-P===

===APIM DTC None===
Successful DTC reading, no error codes found

Module: Accessory Protocol Interface Module

===END APIM DTC None===

===FCDIM DTC B119F:11-28===
Code: B119F - GPS Antenna

Additional Fault Symptom (:11):
 - Circuit Short To Ground

Status (-28):
 - Previously Set DTC - Not Present at Time of Request
 - Malfunction Indicator Lamp is Off for this DTC

Module: Front Control/Display Interface Module

===END FCDIM DTC B119F:11-28===

 

Not sure on the GPS error code (not noticed any issues with the satnav, and wasn't sure if this was just something that might have flagged up after I had changed the battery). Changing the battery was a minor faff needing what felt like 3 pairs of hands to lift the battery out, a set of rubber gloves and a new pair of boxers (the spark when re-connecting the ground wire surprised me to say the least 💩).

The fuel pump error is there for both PCM and OBDII codes.

Found another video while searching the P2636 code which also points towards the low fuel pressure sensor:

For now, I've cleared the codes, and I'm hoping that the weird behaviour is possibly linked to the original battery (was ~9.5 years old) being on the way out. With the new battery, touch wood, so far things have driven ok without any issues or warnings. I'm going to take a longer drive later today (~22 miles each way) and see what happens.

 

I'm likely going to curse myself now, but after my longer drive earlier this evening, and drive back, no issues.  I had a slight feeling something would happen on the drive out, but after getting back into the car a few hours later, the drive back was also event free.

I'm 90% sure now that the battery was the cause of all the weird issues. I'll hold out on the last 10% over the next week and see what else happens (or doesn't, fingers crossed).

After what seemed like ages, I was coming back from Tesco the other night and the damn car had the same problem.

Yet again the error log shows:

 

===PCM DTC P123A:62-6C===
Code: P123A - BARO - Turbocharger/Supercharger Boost Sensor 'A' Correlation

Additional Fault Symptom (:62):
 - Signal Compare Failure

Status (-6C):
 - DTC Maturing - Intermittent at Time of Request
 - Malfunction Indicator Lamp is Off for this DTC
 - Test not complete

Module: Powertrain Control Module

 Freeze Frame  #1:
-LOAD: 27.84 % - Calculated Load Value
-ECT: 194 °F - Engine coolant temperature
-RPM: 1418 1/min - Engine Revolutions Per Minute
-FUELSYS: OL - Drive  - Fuel System Status (Open/Closed Loop)
===END PCM DTC P123A:62-6C===

23 minutes ago, Zico said:

After what seemed like ages, I was coming back from Tesco the other night and the damn car had the same problem.

Yet again the error log shows:

 

===PCM DTC P123A:62-6C===
Code: P123A - BARO - Turbocharger/Supercharger Boost Sensor 'A' Correlation

Additional Fault Symptom (:62):
 - Signal Compare Failure

Status (-6C):
 - DTC Maturing - Intermittent at Time of Request
 - Malfunction Indicator Lamp is Off for this DTC
 - Test not complete

Module: Powertrain Control Module

 Freeze Frame  #1:
-LOAD: 27.84 % - Calculated Load Value
-ECT: 194 °F - Engine coolant temperature
-RPM: 1418 1/min - Engine Revolutions Per Minute
-FUELSYS: OL - Drive  - Fuel System Status (Open/Closed Loop)
===END PCM DTC P123A:62-6C===

I don't know if it is relevant or not but when this fault occurred the Engine was at full temperature but the Fuel System was in Open Loop, so maybe it was very shortly after starting an already warm Engine. 

One of your previous screenshots was the same, I'm not sure what that means unless there is another problem that prevents the car going into Closed Loop, or maybe it was in Closed Loop and the fault switched it into Open Loop. 

The first time the issue occurred, I was quite literally just leaving the supermarket and stopped at the junction a few hundred metres up the road. The car had been driving for a few miles beforehand but had probably sat at the supermarket for about ~30 minutes before I set off back home.

The other night I drove out of my way to the same supermarket (6.2 miles according to Google Maps) and then probably spent about 45 minutes inside before I went to drive back.  The issue happened in a very similar spot only a few minutes after I had got back into the car. Loss of boost, and I had to downshift to keep momentum.

When I did get back home, I pulled up and was idling for a minute or so and the car did cut out.  On re-starting it almost immediately, it started up fine.  I took the DTC codes the next day as I was not in the mood to check it straight away.

I forgot to add, on Saturday I had to go and get my booster jabs and needed to drive a few miles to the surgery. I set off well in advance of the time I needed to arrive, and I gave the car a few minutes to warm up (I have always done this to the point where you can hear the sound of the engine change / the live MPH reading drop from ~0.5mpg to ~0.2mpg) before heading off.

The boost sound was not right, and the car didn't seem to have that oomph but I managed to get to the surgery without anything cutting out.  As I arrived very early, I found a place to park and left the card to idle for ~15 minutes or more before I finally turned the engine off and waited a further ~10 minutes before going in.  I was probably in the surgery for about 20 minutes before I was back out and in the car. I started and left it a minute or so before I drove back.  Again the boost sound was not right, and things didn't quite feel right, but I had no service warning or problem getting back home.

I'm stumped as to what the heck is going on.

Mini update.

Been back to the local garage that has been helping me try and diagnose the problem. They did some checks/smoke tests etc., the last time they had it and found nothing, and didn't charge me anything for the time they had spent on it.

After I dropped in at the garage last Friday, they took the car for a brief test drive while I was waiting and had no issues during the test drive, but on getting back into the garage and parking up, the fault pinged up again (not sure if it was after they had turned off/re-started the ignition as I wasn't in the garage at the time).

They managed to get the MAP sensor that is connected via the lower pipe near to the radiator and swapped that over, and at the same time had a spare boost sensor that fitted in near to the engine oil fill port, and swapped that over as well.

Apparently the MAP sensor underneath the car on the pipe isn't sold by Ford as a single part, with the part number being that of the sensor and the pipe as a unit. The cost would have been ~£225 for that, but luckily the Ford Focus sensor was £25.25 and fits perfectly fine for the same 1.6 turbo engine. The other boost sensor at the top costs ~£86 so a tad more expensive.

After several different drives over the last few days, touch wood nothing else has re-occurred. If it is just the sensor/s, then ~£110 of parts isn't that bad. They even said that if the lower MAP sensor didn't fit/solve the issue, they weren't going to charge me. Still with the water pump + timing belt, plus servicing that I would be doing at least for March next year, I'm going to be giving them some business to make up for the free help.

Hopefully that is the problem fixed.

For information and from your description the lower Sensor is the actual Boost Pressure Sensor i.e. the Pre Throttle one, and the other one is the actual MAP Sensor. I don't know why there is a difference in price between the two unless only the MAP one has a Temperature Sensor as well.

If FORScan had shown the Boost Pressure as a Pressure as it does in some other cars rather than a Voltage it would have been a lot easier to diagnose yourself, especially if using the Phone version of FORScan.

10 hours ago, Zico said:

Mini update.

I would hate to have read a full update 🤣

That was a cup of coffee and two chocolate biscuit long 😉

16 hours ago, Tizer said:

Hopefully that is the problem fixed.

For information and from your description the lower Sensor is the actual Boost Pressure Sensor i.e. the Pre Throttle one, and the other one is the actual MAP Sensor. I don't know why there is a difference in price between the two unless only the MAP one has a Temperature Sensor as well.

If FORScan had shown the Boost Pressure as a Pressure as it does in some other cars rather than a Voltage it would have been a lot easier to diagnose yourself, especially if using the Phone version of FORScan.

When they test drove it that Friday, there was one guy with a laptop running FORscan so they must have been checking the relevant sensors etc., but it just didn't appear to be showing anything out of the ordinary apparently. The one guy even checked on another Fiesta ST that they had at the garage but that was modified so they had different values for the same actions tested (and they have even said that they have another Fiesta that they could get in to check my car against / test swap other sensor/s if needed).

I could get the mobile version on Android, but would that operate using the same cable adaptor (I have a USB-C to A adaptor so in theory it could plug into my Pixel phone.

15 hours ago, unofix said:

I would hate to have read a full update 🤣

That was a cup of coffee and two chocolate biscuit long 😉

Hey, I know I go on a bit (and then some) but you got a lovely bedtime story, coffee and chocolate biscuits and can blame it all on me .

I could do a shorter version, something akin to a picture speaks a thousand words, but it would probably be too big a file size to post