Ford Focus Mk2 Common Problems Thread

[Hobgoblinpie]

Had a go with Forscan just now. Interesting results. 

The APS1 voltage (IC module) reads perfectly fine, with no lagging or other problems. The PCM module has certain data points that can be read, like TPS voltages, Throttle Position etc. Given that they read properly, I'm not inclined to believe that the TPS is necessarily the problem, but that maybe the connectors are. The PCM module has a read-out for APP, which reads out as a percentage, but in this case does not move at all from 0%, even with my foot mashed to the floor. 

I haven't removed the cable from the TPS yet, so I'll try that tomorrow. But at least the IC is ruled out. It could be TPS, ECU/PCM or the wiring. At this point I'm hoping it's the TPS, since Wiring/ECU/PCM faults are going to be serious money.

EDIT: Does the Accelerator Pedal Position Sensor run to both the IC and the PCM at the same time, or to the IC and from the IC into the PCM?

[Tdci-Peter]

1 hour ago, Hobgoblinpie said:

Does the Accelerator Pedal Position Sensor run to both the IC and the PCM at the same time, or to the IC and from the IC into the PCM?

It runs from two separate sensors, on the same shaft, to both modules at the same time. I suspect the PCM uses its own reading as a primary source, but it will read the data from the IC over the CAN bus, and compare the two to flag up any errors. For safety, it will use the lower of the two. A significant difference should raise a DTC.

If the PCM APP reading is not moving, that does point to the APP sensor, or its wiring, that goes to the PCM. I seem to recall that the APP sensor unit was replaced?

The software in these cars does sometimes defy common sense logic though. It is just possible that a TPS problem is forcing the PCM APP reading to 0%, but that seems a daft thing to do to me! Try it with the engine running, if you have not already done this.

Oh that reminds me, does it run, and idle ok? The PCM will need to control the throttle body in order to start and maintain idle. If it can maintain idle with the a/c on/off, and varying alternator load like lights & de-misters, then that make TPS problems less likely.

[Hobgoblinpie]

40 minutes ago, Tdci-Peter said:

It runs from two separate sensors, on the same shaft, to both modules at the same time. I suspect the PCM uses its own reading as a primary source, but it will read the data from the IC over the CAN bus, and compare the two to flag up any errors. For safety, it will use the lower of the two. A significant difference should raise a DTC.

If the PCM APP reading is not moving, that does point to the APP sensor, or its wiring, that goes to the PCM. I seem to recall that the APP sensor unit was replaced?

The software in these cars does sometimes defy common sense logic though. It is just possible that a TPS problem is forcing the PCM APP reading to 0%, but that seems a daft thing to do to me! Try it with the engine running, if you have not already done this.

Oh that reminds me, does it run, and idle ok? The PCM will need to control the throttle body in order to start and maintain idle. If it can maintain idle with the a/c on/off, and varying alternator load like lights & de-misters, then that make TPS problems less likely.

I've attached a screenshot of the logs and added a few annotations to make some things clearer. The voltages in the TP1 and TP2 parts go up and down a bit due to normal variance and adjusting to idle, but are otherwise unchanged since no signal is sent to it via the APP.

I would expect the IC APS1 read out and the PCM APP read out to be the same, since the APP % should just be a conversion from Voltage into "% of max". As you said that the APP sends a signal to both at the same time, I'm disinclined to believe that it's the IC at fault (which is what the garage reckoned it would be), but they replaced the accelerator and that seemed to have no effect. It's making me think that it's a problem in the wiring/connectors from the pedal sensor to the PCM (hopefully not the PCM itself, otherwise I'm going to be paying out of the nose). It acts like the sensor isn't connected at all, let alone malfunctioning.

The car starts up perfectly and idles fine. I can drive it around on tickover, but I'm limited to 5MPH on flat surfaces, so can't use it for actual driving. I though it originally might have been the AC since that was repaired this year by the guy I bought it from, but the error comes up regardless, as with the front and back windscreen heaters.

Let me know what you think, I really appreciate you taking your time to help.

[Tdci-Peter]

4 hours ago, Hobgoblinpie said:

I'm disinclined to believe that it's the IC at fault (which is what the garage reckoned it would be), but they replaced the accelerator and that seemed to have no effect. It's making me think that it's a problem in the wiring/connectors from the pedal sensor to the PCM (hopefully not the PCM itself, otherwise I'm going to be paying out of the nose). It acts like the sensor isn't connected at all, let alone malfunctioning.

Yes, but I am a bit confused. Though that is nothing unusual .

Everything stacks up with the wiring from APP to PCM, except one thing.

The IC looks fine, it sees the APP ok, & there is not a load of U DTCs in Forscan, so it must be communicating with the PCM ok. I had loads of U DTCs when my IC failed. The APP signals to the PCM should be entirely separate from the signals to the IC. It has a +12, a 0v, and a PWM signal to the PCM. Though see below.

I assume the wiggles in the IC APS1 line were you testing it. And the PCM APP line is flat as a pancake.

When the TPS fails, usually the first problem is idle control as this needs very fine control of the throttle valve. Driving on idle is a real test of idle control, so the throttle valve is almost totally ruled out as a problem. I have no real idea what the TPS voltages for a modern petrol engine should look like, but the lines look pretty sensible to me. (The graph took some enhancing to make it visible. There is a button on the bottom right of the Forscan graph screen that turns it white, I have found this looks clearer on browser displays)

The PCM just ignores the APP.

But the confusing bit is the green line called Error, it looks like it always reads zero. However there is no scale on this line. Forscan works in odd ways, its wonders to perform. Maybe it is flatlining at 100% (always in error), and that is the result on the graph. Try dashboard  or table mode, to see if it comes up with an actual value.

If the error reads 100%, or 1 or similar, then I would say it must be the wiring or fuse or even a faulty replacement APP. If the error reads 0, then I would say try a PCM reset. It can't make it any worse!

I have just noticed there is a fuse in the PJB (passenger fusebox) for the PCM APP sensor. It is F75 in the older fusebox, or F138 in the later one. It supplies 12v to the PCM (but not the main 12v), and to the APP. Definitely worth checking!

In the picture below, pin 4 on the APP is ground, pin 5 goes to the PCM, and the triple lined box at the bottom is the IC.

 

[Hobgoblinpie]

10 hours ago, Tdci-Peter said:

If the error reads 100%, or 1 or similar, then I would say it must be the wiring or fuse or even a faulty replacement APP. If the error reads 0, then I would say try a PCM reset. It can't make it any worse!

I have just noticed there is a fuse in the PJB (passenger fusebox) for the PCM APP sensor. It is F75 in the older fusebox, or F138 in the later one. It supplies 12v to the PCM (but not the main 12v), and to the APP. Definitely worth checking!

In the picture below, pin 4 on the APP is ground, pin 5 goes to the PCM, and the triple lined box at the bottom is the IC.

That's very interesting. I would never have thought that. I just had a look at a fusebox schematic, and #30 in the Engine Bay does both the PCM and Automatic Transmission (assuming the car has one), which I assume would be the main line for it. #75/#138 does PCM/APP/AM so I would think that it specifically does the line between the PCM and the APP (hopefully, since the car does read out to the IC properly). 

I've got some time today (and some sunshine) so I'm going to check the fuses first, then go from there. Thanks again!

[Hobgoblinpie]

Had a go today, can't remove the TPS from the throttle body because by the looks of it the clip that is supposed to be pulled out to allow the cable to wiggle free has been pulled out. Therefore the only option with that is to try and unbolt it from the throttle body - something I don't want to do since the bolts are bolted in with glue.

Tried the fusebox, contacts seem fine, tried it without the fuse and the car refused to even start at all. 

I had a look at the wiring for the accelerator pedal, but it's not 6 wires arranged in a rectangle, it's 6 wires in a line, so wasn't quite sure which to try.

Looking to me like wiring or ECU problem. If it's ECU I'll probably just scrap it or sell it for spares/parts/repair. Have to figure out which thing it is though.

[Tdci-Peter]

2 hours ago, Hobgoblinpie said:

it's 6 wires in a line

I would expect to see earth on pins 3 & 4, 12v (Ign On) on pin 6, 5v on pin 1. That is on the connector on the cable. If you can back probe the pins with the connector connected to the APP, then I would expect pin 2 to be a varying voltage that tracks the pedal, in the 0 to 5v range somewhere. Pin 5 is supposed to be PWM, but most multimeters will read this as a varying voltage that tracks the pedal also, somewhere in the 0 to 12v range.

Google Back Probing if needed, basically it uses pins with wires attached to push alongside the cable entering the back of the connector until it touches the crimp terminal inside.

Connector layout, and a better copy of the schematic page is below. It has still lost a bit of resolution compared to the original, I must find a good way to extract pages from big PDFs! The full schematic (132 pages) is available for download on this site.

What a pity it does not seem to be the fuse!

1-6ENG1.pdf

[webby37]

Finally been told what the issue is with my car. According to the diagnostic,  it's an injector and possibly the fuel pump. I have been advised to change the injector and if the issue still occurs, to have the water pump changed. Total cost is going to be over £1100 

[Tdci-Peter]

2 hours ago, webby37 said:

According to the diagnostic,  it's an injector and possibly the fuel pump. I have been advised to change the injector and if the issue still occurs, to have the water (fuel?) pump changed.

The diagnostic codes provide clues, but are not to be taken as 100% correct! It says that in all the manuals. They must be used in conjunction with the symptoms, and further diagnostic tests.

The symptoms (total lack of power during acceleration) do not really stack up with one injector failed. It needs a leak-off test or full injector test to confirm a failed injector, before expensive replacement.

Does the car run smoothly when trundling along at idle speed, and pick up ok from that speed? That is quite a good test for any injector mis-matches, as it should give lumpy running.

The symptoms do match with a failure in the pressure regulator valve or volume control valve, possibly. These are mounted on the fuel pump, and should be available for replacement separately, though many people regard them as part of the pump. There are tests that could be done, like logging the fuel pressure & valve control signals, to narrow down the problem, before very expensive fuel pump replacement.

With a price tag like that looming, I suggest a second opinion would be a wise move. Just replacing expensive bits one after the other on the basis of an undisclosed "diagnostics" seems bad practice to me!

[webby37]

Thanks for the reply. The car runs smoothly at idle and smooth when accelerating. I sometimes feel a bit of very slight holding back at low speed but nothing major and the odd bit of a kangaroo scenario at very low speed. I can quite often accelerate right over 3000 rpm in 1st and 2nd gear but it's not until 3rd that the power drops at 3000rpm. I have actually  noticed that it does this when the engine is cold. I haven't taken it up to 3000 rpm since my original post and although there is a slight lack of power at times, probably due to the low revs, it drives fine. I'll definitely get a second opinion on it but you have given some hope, so thank you

[Tdci-Peter]

6 hours ago, webby37 said:

I can quite often accelerate right over 3000 rpm in 1st and 2nd gear but it's not until 3rd that the power drops at 3000rpm

I recommend you write down the symptoms carefully, and give them to the garage with the car. What I feel may be important is:

" I have got to the point now that if I accelerate in any gear to anywhere near 3000 rpm and sometimes 2500 rpm, I lose power as in it feels like the engine has run out of steam. As soon as I back off the accelerator, then put my foot down again, it picks up and can accelerate again. "

But maybe updated with any later findings.

It sounds like a sticky control valve or actuator, or maybe even a dodgy sensor. In higher gears, the RPM increases more slowly, and fuel & air demand increase similarly slowly, And that is when whatever is wrong sticks. By releasing the throttle, and re-applying it, it can go through the dodgy bit, and be ok again.

The diagnostic codes may narrow it down to air flow (turbo actuator, air flow & pressure sensors), or to fuel pressure. Either way, identifying one dodgy injector when the air or fuel pressure is wrong and may be varying, is unreliable. Just because an injector DTC comes up is no guarantee, another fault could be the cause.

A garage that is a diesel specialist might be a good idea. If it is fuel pressure related, as the first garage believes, they will better be able to do further tests.

Also ask them if they have heard of the bad batch of 1.8TDCI injectors with the 3 code. If all 4 injectors are failing, it would be best to know that before any major work is done. Added to uncertainty of if or when the lower timing belt was serviced, it will help avoid that scenario of costing more than you can really afford.

I hate to be a doom monger, hopefully there will be a cost effective fix. But going down the route given by the first garage could, in the worst case, be one new injector, then fuel pump, then 3 more injectors, then both timing belts. Not a nice scenario. Which is exactly why I am questioning their diagnosis & route, and recommending further tests, even if it is inconvenient & may incur some costs.

If we can rule out injectors, then doing the fuel pump and both timing belts in one job would be a lot cheaper than doing them separately, There is a lot of common labour. So that is a kind of positive view!

My 1.8TDCI injectors have done 160k miles, and are still going, so they can last a very long time.

[Hobgoblinpie]

I got that 'error' graph to work, that's the Throttle Pedal read out in volts, and when I tested it just now, it was at a minimum of 14.51 Volts, max of 15.69 Volts. This seems incredibly high, I figured the max would be 12V. The P2121 code gives it as 'exceeds maximum specification', and it certainly seems so going off that. Any ideas on the correct voltages, or if you could test yours to see? Thanks.

[Tdci-Peter]

2 hours ago, Hobgoblinpie said:

it was at a minimum of 14.51 Volts, max of 15.69 Volts. This seems incredibly high,

It certainly does seem high!

If that was with the engine running, I would just check the battery voltage to make sure the Alternator is not chucking out some ridiculous value. Very unlikely, there would be loads of other errors if it was.

It could be a software error, maybe a scaling error in Forscan. Back-probing the connector would double check that.

Unfortunately, the only way I can see that a voltage reading read from the PCM reads well over battery voltage, is a PCM fault, a resistor gone open circuit in the input circuit from the APP to the A to D input in the PCM. These inputs will be 0-5v or less, so need scaling resistors to measure over 5v. I am out now, probably till Sat Eve / Sunday. I will try to look a bit more then. I hope there is another answer!

 

[Hobgoblinpie]

I think I misread the graph, I got too focused on the number and it was % instead, so I assume that's Throttle Position %, not pedal. Still, 15% seems quite high for idle. I'll do some more testing and get back to you.

[Hobgoblinpie]

Just had another guy, but read the tips it gives you when you scroll over the different sensors. Saw on the PCM module APP sensor that if one signal is malfunctioning it will use the other two signals to read from, and if two are malfunctioning it will use a 'safe value'. For the throttle it seems to me that the only safe value would be 0 (imagine if it set it to 100% acceleration as a safe value for instance). 

P2121 is that the APP signal exceeds the maximum acceptable values (via PCM), so my theory is that two wires, possibly low and high voltage, are shorting into each other, causing the low voltage wire to read much higher. 

I can't prove that of course, but that's my speculation on the matter. I can't imagine it would tell me that voltage was too high if a wire were disconnected. I'm going to put it into a different garage next week and go from there I think.

[Tdci-Peter]

On 12/15/2017 at 7:20 PM, Hobgoblinpie said:

I got too focused on the number and it was % instead,

That is good news (relatively!). Reading a high voltage puts the finger of suspicion on the PCM, but 15% could well be wiring. I also find it hard to see how wiring faults could give steady readings above the battery voltage, as the APP is very unlikely to have any sort of voltage boosting circuit in it. However it is quite possible for a broken wire to give high voltages (above the expected signal), but that are within the battery voltage range. Some electronic circuits have very high input impedance that is sensitive to tiny leakage and capacatively coupled currents. A mulimeter input (10Meg Ohm input) floats about all over the place when disconnected, just by touching the leads.

Tracing the wiring from APP to PCM is not very easy. The PCM has a cover with a security (headless) bolt, that has to be drilled or ground out to access the connection pins. I recommend giving the garage written records of symptoms & Forscan runs, otherwise they will be tempted to start again by replacing the APP again, rather than the tedious job of checking the wiring and voltages on it.

[ews77]

Hi All. New to the site and hoping you may be able to shed some light on a couple of issues I have with my 2010 Focus Zetec S 1.8.

First problem that I have had for a while is the car bogging down a bit or revs a bit random, all whilst warming up. Quite often I go to pull away from a junction and the car just doesn't want to go, then it kicks in and gets going. Once the car is up to temperature all works ok.

Second problem is the immobiliser light randomly coming on whilst driving and at the same time the stereo turns off momentarily. Light goes off again and stereo back on.

Many thanks in advance, and hope I've posted in the right place!

Thanks

[Hobgoblinpie]

13 hours ago, Tdci-Peter said:

Tracing the wiring from APP to PCM is not very easy. The PCM has a cover with a security (headless) bolt, that has to be drilled or ground out to access the connection pins. I recommend giving the garage written records of symptoms & Forscan runs, otherwise they will be tempted to start again by replacing the APP again, rather than the tedious job of checking the wiring and voltages on it.

I'm going to write out an information sheet for them, of prior symptoms, steps taken, and graphs taken from Forscan so that they can more quickly get to the issue. If I'm paying £70 per hour, I definitely want to avoid more steps in the process.

I didn't know how difficult it was to get to the PCM, a lot of this stuff seems to be made to make it as hard as possible to repair at home (putting loctite on the bolts for the TPS, for instance). I mean, I know that that's why they do it, I just didn't expect for it to be a problem for me!

[Tdci-Peter]

3 hours ago, ews77 said:

the immobiliser light randomly coming on whilst driving and at the same time the stereo turns off momentarily. Light goes off again and stereo back on.

One link between the stereo & the IC (cluster), is the Aux supply for the stereo also goes to the IC. I think it tells the IC when the engine is cranking (starting), as the Aux supply goes off then. I think the immobiliser LED lights during cranking, but have not checked. If so, then a dodgy ignition switch, or wiring in the Aux line from the switch, could do what you describe. I assume the engine is not affected by this problem.

Re the engine problem, is it 1.8 petrol or TDCI?

If petrol, I would suspect throttle body first, then maybe coil pack or HT leads (if it has HT leads).

 

[Tdci-Peter]

4 minutes ago, Hobgoblinpie said:

a lot of this stuff seems to be made to make it as hard as possible to repair at home

I think you are being slightly unkind!

It might be more accurate to say they do not care how hard it is to repair, and will not spend a penny to make repairs easier.

They are paranoid about some bolts coming undone, despite a tiny, remote possibility, and over-tighten or thread lock them.

The ECU protection is intended for added security against theft, though in practice it is virtually ineffective in this, well equipped crooks will have no problems. Like most "security" measures, it mainly hits law abiding owners .

But the end result is the same as you way, they do make it hard to repair, either at home or by most garages. I used to think Ford had a good attitude to overall cost of ownership, including maintenance & repair, as this was quite important to high mileage corporate customers. But this attitude seems to have gone now.

[ews77]

6 hours ago, Tdci-Peter said:

One link between the stereo & the IC (cluster), is the Aux supply for the stereo also goes to the IC. I think it tells the IC when the engine is cranking (starting), as the Aux supply goes off then. I think the immobiliser LED lights during cranking, but have not checked. If so, then a dodgy ignition switch, or wiring in the Aux line from the switch, could do what you describe. I assume the engine is not affected by this problem.

Re the engine problem, is it 1.8 petrol or TDCI?

If petrol, I would suspect throttle body first, then maybe coil pack or HT leads (if it has HT leads).

 

Hi Peter, thanks for this. Will check the immobiliser light later when turning over. When the immobiliser light and sound cut happened first time around I thought it was a call coming through over bluetooth, but turns out it wasn't! I've used the car without my phone on me to check but the issue still happens.

With regards to the engine, it is 1.8 Petrol... I had wondered if a sensor had gone, hence the slightly random behaviour during warm up but ok once warmed up. Will certainly take a look at the items you have suggested though...

[Hobgoblinpie]

Going to post this as I just received the car back from the garage. The car seems to be fixed. I'm not going to say it's 100% fixed yet since I haven't given it a real drive yet, but it seems as before.

The problem was that someone had tampered with the earthing wire before, and was not attached to the correct post. It had been attached to a different wire and wrapped around, and that was causing it to read high voltages. The garage added a new connector to the end of it, attached it to the correct post and tightened it up, and that seems to have completely fixed it. £100 overall for the fix. Hopefully that might help anyone who has the same problem.

The guy who sold it to me had the AC system repaired and all the pipes replaced, my initial thought would be that the mechanic who did it is the one who caused the problem. 

Thanks for all the help Peter, hopefully I don't have to post in this thread again 

[Tdci-Peter]

7 hours ago, Hobgoblinpie said:

The problem was that someone had tampered with the earthing wire before, and was not attached to the correct post. It had been attached to a different wire and wrapped around, and that was causing it to read high voltages.

That is, hopefully, really good news. The APP is earthed to a different point on the body, compared to the PCM, so bad earths could cause odd voltages and upset the readings. Easier than the wiring loom, and much better than a PCM fault!

Did he say which earth wire was wrong, as a matter of interest?

[Hobgoblinpie]

I believe it was the APP wire, as it was an earth wire inside the car (I think it would be strange to earth the PCM inside the car, when it's in the engine compartment). As mentioned by the previous garage the pedal currently in my car is one from a breaker's yard, so I'm betting that that has something to do with it. 

If I had to speculate, when the guy had the AC installed they may have screwed around with some of the wires, and then due to a fault they replaced the pedal with one from a breaker's yard, without solving the actual problem. Then sold it on to me because he didn't want to put more money into it. 

Hopefully this has fully solved the issue, fingers crossed.

[webby37]

On 12/12/2017 at 6:15 PM, Tdci-Peter said:

I recommend you write down the symptoms carefully, and give them to the garage with the car. What I feel may be important is:

" I have got to the point now that if I accelerate in any gear to anywhere near 3000 rpm and sometimes 2500 rpm, I lose power as in it feels like the engine has run out of steam. As soon as I back off the accelerator, then put my foot down again, it picks up and can accelerate again. "

But maybe updated with any later findings.

It sounds like a sticky control valve or actuator, or maybe even a dodgy sensor. In higher gears, the RPM increases more slowly, and fuel & air demand increase similarly slowly, And that is when whatever is wrong sticks. By releasing the throttle, and re-applying it, it can go through the dodgy bit, and be ok again.

The diagnostic codes may narrow it down to air flow (turbo actuator, air flow & pressure sensors), or to fuel pressure. Either way, identifying one dodgy injector when the air or fuel pressure is wrong and may be varying, is unreliable. Just because an injector DTC comes up is no guarantee, another fault could be the cause.

A garage that is a diesel specialist might be a good idea. If it is fuel pressure related, as the first garage believes, they will better be able to do further tests.

Also ask them if they have heard of the bad batch of 1.8TDCI injectors with the 3 code. If all 4 injectors are failing, it would be best to know that before any major work is done. Added to uncertainty of if or when the lower timing belt was serviced, it will help avoid that scenario of costing more than you can really afford.

I hate to be a doom monger, hopefully there will be a cost effective fix. But going down the route given by the first garage could, in the worst case, be one new injector, then fuel pump, then 3 more injectors, then both timing belts. Not a nice scenario. Which is exactly why I am questioning their diagnosis & route, and recommending further tests, even if it is inconvenient & may incur some costs.

If we can rule out injectors, then doing the fuel pump and both timing belts in one job would be a lot cheaper than doing them separately, There is a lot of common labour. So that is a kind of positive view!

My 1.8TDCI injectors have done 160k miles, and are still going, so they can last a very long time.

Update: Someone at work recommended a garage that would look at the issue I was having. They ran a diagnostic that pointed towards injector. First point of call was to check the Fuel filter to make sure that was good. Apparently a blocked/dirty fuel filter tends to throw up an injector fault. If there's not enough fuel getting to the injector, it flags as an injector fault. Turns out mine was very very dirty one and full of bits of crap. Fuel filter changed, injector cleaner run and the car now goes right through the rev range in every gear. £122 instead on £1100 odd. Big thanks to you and everyone else on here for your help and support