Focus Mk2.5 1.6 hesitation

[Focus-Jonny]

Hi Everyone,

Its been a long time since I have been on the forum, hopefully the community is still as helpful as ever 😊

Having a problem with my 2010 Focus Mk2.5 1.6 Ti-VCT, 68K miles. 
 

Car has started intermittently running lumpy at low revs (<2k revs) and hesitating with brief periods were the average mpg readout returns two dashes instead of numerical value, as if the car doesn't know what it is doing. 
 

What has been done recently:

New belts & water pump

New coil pack & Plug leads / spark plugs checked.

 

Any ideas what it could be? only happens occasionally usually after the car has been driven for a bit and warmed up. 
 

Any suggestions would be greatly appreciated. 😊

 

[Tdci-Peter]

5 hours ago, Focus-Jonny said:

hesitating with brief periods were the average mpg readout returns two dashes instead of numerical value

The in car mpg is calculated from the fuel injector pulsewidths, which are controlled by the ECU. This information is then transmitted over the HS-CAN bus to the cluster (IC).

If it was a bus fault, I doubt if the engine would hesitate or run lumpy. The ECU is in charge of all that.

You seem to have ruled out ignition.

So fuel related problems are most likely: fuel pump erratic, bad pressure regulator, or faulty injectors. I would use Forscan to look for DTCs, and to monitor live values like injector pulse widths, cylinder balance.

Unfortunately, once you get to fuel, all the engine systems are inter-related: Throttle valve, O2 sensors, MAP or MAF readings, even camshaft position sensors or actuators, they will all affect the fuel input. Hence the need to use the inbuilt diagnostics as much as possible to narrow it down.

[Focus-Jonny]

Thanks Peter for that info, you sound like you know your stuff, do you live in NI by any chance? 🤞🏻😬 

By the sounds of it this sounds like it will be a nightmare to diagnose. Unfortunately I have no access to diagnostic gear nor are there any good indy ford specialists in my area just a ford dealership 🙄🤑

[Tdci-Peter]

2 hours ago, Focus-Jonny said:

I have no access to diagnostic gear

Bit of a long way from NI to Dorset, I am afraid!

If you have a Windows laptop, or a smartphone or tablet with ios or android, plus about £25 in the bank, then you have access to Forscan. The software is free, (and safe and good!) it just needs an adapter.

http://forscan.org/download.html

One source of adapters with a track record:

https://tunnelrat-electronics.fwscart.com/

Reading the codes is dead easy, recording real time data is almost as easy with a few hints you can get here.

Sadly, interpreting the data is not so easy. The error codes (DTCs), in an ideal world, would point straight to the defective part. This world is far from ideal, especially the world of software! They are right about 50% of the time (by my rough estimation), but still provide useful clues in other cases.

Real time data is even harder, there is so much going on, it is hard to tell cause from effect. But there are cases where it has narrowed it down a lot. You can post data on this site, to see if I or anyone else can help.

It may well not work, but the cost is negligible compared to a Ford Stealer, they start at £100 and ramp up pretty quick. Also, sadly the amount of real knowledge in some dealerships is very low, they rely on just obeying whatever their computer says. So the DIY method might be worth a try!

[Micro]

When you got the dashes, did you notice any other lights or display issues with your instrument cluster?

[Focus-Jonny]

Hi Micro, no nothing else on the dash. I eventually got a engine management light  during one of the bad episodes but has cleared itself the following day.  
 

exhaust can smell a bit eggy, but I am putting this down to the engine running rich during episodes of misfiring. 

As Peter has pointed out a good Diagnostic reader will probably be the next best step for me. 

[Focus-Jonny]

Just ordered the wifi enabled tunnelrat ELM327 (modified) and downloaded FORScan lite for iOS on Friday. Thanks for the links @Tdci-Peter

I will see how this goes, will the iOS app allow me to access all the important data required to diagnose issues compared to the windows version? My Laptop is on its last legs and using my iPhone will be more convenient. 
 

Does anyone have info for nominal sensor values/parameters for the Focus mk2.5 1.6 ti-Vct which I can use to compare against? 

[Tdci-Peter]

On 10/12/2019 at 11:30 AM, Focus-Jonny said:

will the iOS app allow me to access all the important data required to diagnose issues compared to the windows version?

Yes, the IOS app has the same functionality to read all DTCs, access PIDs and Module Self-Test modes as the Windows one. The only limitation seems to be some things like PATS programming and software programming that need the extended license, which is only available for Windows or Linux.

I can try to assist on setting up Forscan, but have only used the Windows version, so the details of the user interface may be different on an iPhone.

I think Micro (Ted) on this site had a ti-VCT, and did some Forscan runs on it. I have found one such run. As the car had a problem at the time, it is not great as a comparison, but at least gives some idea of the PIDs that are available. (A PID is just a value that can be read out of the module, eg ECU, or PCM as Ford then called it.)

A full check of DTCs could rule out bus errors, and may point at a suspect area. Logging data can see if the car is normally achieving closed loop mode or not. This mode is where the fuel/air mix is finely controlled by the O2 sensors to the optimum. Errors and abnormal running (ie start-up) will cause it to use open loop mode where the MAF sensor is use to estimate the amount of fuel needed. From there, with luck, it may be possible to narrow it down to one sensor or system, but it is not always easy!

[DaveT70]

Sounds like a CAN issue to me, probably not in the instrument cluster though, maybe the BCM.

These cars a renowned for leaking water from the HVAC onto the BCM, corroding the circuits.

Our 10 plate Focus died over the same reason.

Take the BCM out and check for any corrosion around any of the pins before you start spending any more money, disconnect battery first 

[Focus-Jonny]

Thanks for the info guys, 

had a play with FORScan today briefly as the ELM327 adaptor arrived. Got the following codes logged:

Status - Confirmed - malfunction is confirmed 
P0201 - Injector circuit malfunction cylinder. 
Module - On Board Diagnostics II

Status - Previously set DTC - Not present at time of request. 
P0301 - Cylinder 1 misfire detected. 
Module - Powertrain Control Module

U1900 - CAN communication bus fault. 
Module - Instrument Cluster

 

[Focus-Jonny]

On 10/14/2019 at 7:26 AM, DaveT70 said:

Sounds like a CAN issue to me, probably not in the instrument cluster though, maybe the BCM.

These cars a renowned for leaking water from the HVAC onto the BCM, corroding the circuits.

Our 10 plate Focus died over the same reason.

Take the BCM out and check for any corrosion around any of the pins before you start spending any more money, disconnect battery first 

Hi DaveT70,

This has me worried because when I first picked my car up from Trust Ford in 2012 about a week later when I went to use the washer jets nothing happened.. long story short it turned out that the control module responsible had corroded, I got this replaced as a goodwill by Ford. 
 

Im hoping that 7 years on this has not reoccurred. Does the BCM control window washers and injector circuits by any chance?  

[Tdci-Peter]

1 hour ago, Focus-Jonny said:

Does the BCM control window washers and injector circuits by any chance?  

'Fraid not!

BCM / GEM / Passenger fuse box (same thing on a Focus) controls wipers, lights, locking, windows, etc. It has the switch circuits for a/c and cruise control, but the ECU actually controls these two, just getting the switch state info from the BCM over the CAN bus.

The ECU is firmly and solely in charge of almost all engine related stuff. From injectors, Turbo & EGR to the cooling fan.

It is certainly true that the BCM is rather prone to getting water damage on these cars, but it does not really stack up with the symptoms here.

 

[Focus-Jonny]

11 hours ago, Tdci-Peter said:

'Fraid not!

BCM / GEM / Passenger fuse box (same thing on a Focus) controls wipers, lights, locking, windows, etc. It has the switch circuits for a/c and cruise control, but the ECU actually controls these two, just getting the switch state info from the BCM over the CAN bus.

The ECU is firmly and solely in charge of almost all engine related stuff. From injectors, Turbo & EGR to the cooling fan.

It is certainly true that the BCM is rather prone to getting water damage on these cars, but it does not really stack up with the symptoms here.

 

Thanks Tdci-Peter,

I suppose the next step would be to swap cylinder 1 injector with cylinder 4 and see if the fault code moves across to that cylinder? 

that would diagnose a faulty injector or point towards a wiring harness issue (short/break) if the fault stays put. Are the focus injectors coded in position? 

[Tdci-Peter]

3 hours ago, Focus-Jonny said:

I suppose the next step would be to swap cylinder 1 injector with cylinder 4 and see if the fault code moves across to that cylinder? 

that would diagnose a faulty injector or point towards a wiring harness issue (short/break) if the fault stays put. Are the focus injectors coded in position? 

I missed the diagnostic codes you posted! Seen them now though.

The U1900 code in the IC does not mean much on its own, it is a very frequent code, often just a result of the diagnostic process.

So two codes on cyl.1 does stack up with hesitations. As far as I know, there is no need to recode petrol injectors. A simple swap sounds like a good idea, since one of the codes points towards an electrical circuit problem.

[Focus-Jonny]

Well got to the bottom of this one eventually.

Injector 1 harness plug was not fully pushed home in the socket. Vibrations from driving must have cause the circuit to break intermittently when it was rattling around. 
 

Dont know how this has happened I suspect it was disturbed by the garage when carrying out my timing belt change.  
 

I’m just glad its all sorted now and the car is driving like a dream again with no more error codes. 😅 thanks to everyone who weighed in with some advice, much appreciated! 👍🏻