On 1/20/2023 at 8:01 AM, EmdoPL said:

@FinnF glad you have it sorted out.

I have a different storry to tell, which is a sad story. I spent so much money for parts and repairs, it exceeded half of the car's value.

After 18 days of repairs and testing at the shop they said I can come and take my car back. They changed oil cooler gasket, cleaned the EGR valve, and they have a refubrished turbocharger fitted, then flushed the engine and changed oil. Next they began to test sensors. Every single sensor that was mounted to the engine was replaced and after each replacement the car went for a drive. Nothing seemed to help. They gave up and i had to pay for what was done already. I paid and I went back home. I barely made it. The engine lost its power,at first I couldn't drive up a little hill near my house. Called them, they took the car back to repair on dec 23. Turned out the conrod bearings were in a very bad shape, the crankshaft too, so I began to look for a replacement engine. Found one, complete, mounted in a crashed Focus MK2, able to run, worked like a new one. Unmounted and transported it to the shop on jan 5. Yesterday I finally had my car back with a "new" engine fitted, everything was looking promissing. They said I have to go to another shop to clean my DPF, because the PCM wants to regenerate it, but something is wrong and they don't know what. Then, when I was in the half of the way to my house, I noticed stuttering again. Anyways, I connected my smartphone to the car with a cheap bluetooth ELM327, checked fault codes, it was the P2458 code and P0166. None of the codes came back after erasing them and restarting the engine. Also I checked the acceleration pedal output in the same app, it seems to be faulty too, about the point where the hesitation starts the chart of the pedal was changing from 10% to 13,5%, but i didn't move the pedal, at other points the chart remained still.

Will clean the DPF at the shop, replace the O2 sensor and I'll check what happens to my acceleration pedal connection, because earlier I have tested the pedal from the other C-Max that I own, with no improvement.

I'll keep You posted 😉 cheers 😉

Just a quick update, problem still isn't fixed! Still doing the little stutter at 1500rpm in 5th gear, think its actually getting slightly worse as its occasionally doing it in 2nd and 3rd gear, but only at really low revs! Feel like its just happening when under low pressure so thinking maybe a fuel pressure sensor? Gonna get my mechanic to drive it for a few days, hooked up to his laptop and see what data he gets. Still not getting any fault codes on the dash.... 

I would love to get to the root of this, however I can't warrant throwing more money at it. So I'm just going to live with it unless I get a eureka moment 🙃. Good luck with yours. 

On 2/20/2023 at 12:17 PM, FinnF said:

Just a quick update, problem still isn't fixed! Still doing the little stutter at 1500rpm in 5th gear, think its actually getting slightly worse as its occasionally doing it in 2nd and 3rd gear, but only at really low revs! Feel like its just happening when under low pressure so thinking maybe a fuel pressure sensor? Gonna get my mechanic to drive it for a few days, hooked up to his laptop and see what data he gets. Still not getting any fault codes on the dash.... 

Had the same issue before my previous engine died...


Anyways, after replacing the engine I replaced the thermostat, and cleaned electrical grounds under the air cleaner box, then I made about 3000km (including more than 1000km on the highway) with the MAF sensor not plugged in. The car was running great, but the MIL was annoying. Every time I tried to plug the MAF in, the result was the same. Three days ago I was surprised to see a red battery light on the dash, it was an alternator smart charging fault. So I took the car to the electromechanic's shop, where the alternator got repaired. To get to the alternator they had to remove the intake hoses and the intercooler bypass throttle, so everything got cleaned and one plastic elbow with a rubber seal had to be replaced, because the rubber seal was swollen (it was mounted inproperly and the oil mist from the intercooler was getting out, covering everything nearby and the seal itself with oil).

After this repair the stuttering occurs only ocasionally on each gear, and only when the engine is cold and the MAF is plugged in. So i guess everything that has electricity in it is a little messed up because of faulty alternator. I am willing to look inside the plastic box in the wheel arch where the PCM is hidden, because I suspect something is not right with wiring. The proper sealing of the intake could be a good hint too, so I recommend it to be replaced anyways.

 

⚠️WARNING!⚠️ The seal has a pocket where the elbow goes and then you should put it on the inlet of the throttle body! The seal is not to be sold separately! Use caution when installing, no lubrication allowed, and it goes on very tight, it is easy to break the throttle body mounts!

Hello all. Has anyone managed to sort this out yet. Still scratching my head 😆.....

With electrical issues on a mk2/2.5 Focus, I think I would check the BCM/Fusebox and plugs for signs of dampness and corrosion first followed by the instrument cluster solder issue, Hitting or wiggle testing the plug. 
DTCs read by Forscan using a reliable elm327 lead capable of reading both can busses may show error codes. The cheap or generic cables often don’t read both.

Will do some checks. Thank you. 

On 3/21/2023 at 2:13 PM, RL123 said:

instrument cluster solder issue

I wonder what the instrument cluster has to do with the TPS.
Do You know if the IC is sending signals from TPS to the PCM, or what?

I attempted to fix the soldering issue, but with my poor soldering skills and cheap soldering iron, I am glad that everything works properly so far, but the issue of stuttering we are experiencing didn't change for me as long as the MAF is connected. With MAF disconnected the engine runs good as new, but the Check Engine light is driving me crazy. Also the avg. MPG is not calculated right, i think.

On 3/25/2023 at 11:20 PM, EmdoPL said:

I wonder what the instrument cluster has to do with the TPS.
Do You know if the IC is sending signals from TPS to the PCM, or what?

Everything runs through the cluster, that's why everything goes wrong if/when the solder gets dry and disconnects the contacts for the plug on the back.

2 hours ago, LarsfromNorway said:

Everything runs through the cluster, that's why everything goes wrong if/when the solder gets dry and disconnects the contacts for the plug on the back.

Sorry but that's a very flawed description. In one respect the IC is just another node on the "high speed" CAN bus (network), a shared communication medium. On my Mk2.5 Focus there's also a secondary "mid-speed" CAN bus and the IC is also a node on that. Furthermore the IC acts as a gateway between the two buses, so yes it can indeed affect any communication that may happen to take place between modules on the different buses, but it's wrong to say that "everything runs through the cluster" as though it controls all exchange of communications within buses and between modules and sensors/actuators.

Another important detail for CAN buses is that there should be a pair of terminating resistors connecting the ends of the pair of bus wires. The purpose of these terminating resistors is to absorb signal reflections ("back EMF" I believe it's technically called) that could otherwise be a source of interference to bus communications. These terminating resistors are sometimes (always?) actually located at a node towards each far end of a bus. The IC, in my Focus at least, has one of the terminating resistors for each of the two buses it is a member of.

So the chaos caused by the faulty IC solder joints can presumably be attributed somewhat to loss of a terminating CAN bus resistor if the IC's CAN bus connector pins are cracked, besides general malfunction due to poor electrical connections and connections opening/closing as the environment changes in terms of e.g. temperature and flexing of the vehicle.

I stand corrected😄

2 hours ago, LarsfromNorway said:

I stand corrected

said the man wearing orthopedic shoes 🤣

On 3/21/2023 at 11:59 AM, AlwaysTrouble68 said:

Hello all. Has anyone managed to sort this out yet. Still scratching my head

I'm probably getting a bit confused as there are three of you with similar symptoms on this thread, but as far as I can see, both Finn and Endo have solved the problem by addressing the MAF sensor.  So I would disconnect yours and see if that cures your problem too.

If that does help does this mean a new maf? As surely driving around with the mil lamp on isn't a great idea. 

Thank you 

This did help. Stuttering gone when MAF disconnected however the EML light stays on. What next does anyone know?

Thanks to all.

5 hours ago, AlwaysTrouble68 said:

the EML light stays on.

What is the active DTC ?

Use FORScan to read the code: https://forscan.org/download.html

The EML can be triggered by the disconnected MAF on later 1.6 TDCIs.

Without a MAF input, the PCM uses a richer failsafe mixture which can mask other faults.  Running better like this doesn't necessarily indicate a faulty MAF.

On 4/27/2023 at 1:01 AM, alanfp said:

I'm probably getting a bit confused as there are three of you with similar symptoms on this thread, but as far as I can see, both Finn and Endo have solved the problem by addressing the MAF sensor.  So I would disconnect yours and see if that cures your problem too.

Sorry for digging up the old thread, but it's still open, so... 😄

Actually I didn't end up solving the issue. I have the soldering on the IC redone, I have the whole engine replaced and still got the issue.
I am planning to clean the probably gunked up intake mainfold and replacing the EGR, but still don't have enough time to do so. Still driving like a charm for 11 months now with EML lit on the dash and the MAF sensor unplugged.

Driving me crazy, but hey, it runs!

Maybe when the spring comes i'll have some time to undo the mainfold and have a look inside.
Cheers 😉

Hi. Blimey! a lot of work then?

Mine still playing up with the fault. I wonder if the Peugeot/Citroen have the same issue? I'm beginning to wonder if its a Map Error with the manufacture. Hmmmm!   

Hey, just came here to give you a hint, because mine is cured now, at least when idling, later I'll take it for a test drive and we'll see. 

I just swapped the GEM module, dunno if that helped, but it ain't gonna cost much, and is worth a try. My guess is that the old module interfered with voltage regulator and made it go crazy, so the reference voltage was changing too quickly and that's what made it stutter. 

 

@AlwaysTrouble68 try doing that, worth a try. 

23 minutes ago, EmdoPL said:

Hey, just came here to give you a hint, because mine is cured now, at least when idling, later I'll take it for a test drive and we'll see. 

I just swapped the GEM module, dunno if that helped, but it ain't gonna cost much, and is worth a try. My guess is that the old module interfered with voltage regulator and made it go crazy, so the reference voltage was changing too quickly and that's what made it stutter. 

 

@AlwaysTrouble68 try doing that, worth a try. 

Will give it a go. I have been a techie for years but I have had a brain *****. GEM ??? Maybe I know it as something else. Thank you anyway. 

GEM - General Electronic Module (Integrated with the fusebox under the glovebox)

On later cars it's called a BCM - Body Control Module

It does also have other acronyms with other brands.

Ah got u now thanks. Also any idea as to why my instrument cluster is playing up? Makes a strange noise when ignition turn on and the clock needs resetting multiple times. 2010 face lift 1.6 tdci. Thanks again. 

1 hour ago, AlwaysTrouble68 said:

Ah got u now thanks. Also any idea as to why my instrument cluster is playing up? Makes a strange noise when ignition turn on and the clock needs resetting multiple times. 2010 face lift 1.6 tdci. Thanks again. 

The clusters are a known weak point due to solder cracking on the PCB.  

There are plenty of places offering cluster solder repairs, unless it's something you can do yourself.

Thanks for that. Will give it a go. Will let you know how I get on. 

On 3/26/2024 at 4:30 PM, AlwaysTrouble68 said:

Thanks for that. Will give it a go. Will let you know how I get on. 

Did you ever find a fox for this mate?