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Post by valhalla on May 28, 2021 14:11:17 GMT 1
I have a strange one on the ramps right now, and I don't know if anyone has come across anything similar to this on Mondeo (or similar) before;
It has an intermittent problem with the engine derating and going into limp-home/no start, but I have not seen this yet, it has only happened with the customer.
I can see that both engine controller and smart fusebox/multifunction controller are flagging intermittent faults on clutch switch and accelerator pedal, as well as intermittents on CANbus comms going down (which I'm keeping at the back of my mind, but not treating as the primary problem, for reasons I will explain below).
The clutch switch is power fed from the multifunction control directly, and earths via a common ground to the RH A-post/sill, i.e it is a signal pull-down switch into the multifunction. The accelerator pedal is powered via a fuse in the multifunction, but that derives a voltage signal within itself for each of the tracks, and feeds those back to the multifunction. So it works slightly differently, but still grounds via the same earth wire to the A-post/sill. Logic dictates that this is the problem, EP2 is not making good contact/loose, broken wire, etc. Except, I cannot find a problem in any of this bit of harness/connectors/earth-point.
All signals for the pedals are processed by the multifunction, and sent to the engine controller over HScan. This has an intermittent problem, as stated above, but I discount this (maybe incorrectly?) because the multifunction itself has its own internal fault-codes for the raw clutch and acc-pedal signals. So it knows itself that there's a problem, and is therefore likely to be flagging that subsequently to the ECU.
Behind all this mess, there is, in-fact, a mess; the main underbonnet fusebox has has vermin, both outside and inside, and I have photographed the issues as-presented to the naked eye. The box is loose, but I haven't opened it yet, and that is what I want to avoid - fixing something that doesn't need fixing, unless it can be linked to the issues with the multifunction controller. Opening this fusebox looks to be a bigger job than I had anticipated, and I cannot see any issues when I poke the endoscopic camera in there. On the other hand, it is the only solid evidence I can find of any likely fault-cause.
Anyone know or guess whether faults underbonnet can give strange faults on the multifunction? There are no other codes on anything across the car except related to the clutch switch, acc-pedal, and CANbus issues.
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Post by Rhubarb on May 28, 2021 14:29:58 GMT 1
Methinks I would start by checking all the earth leads and points  And elsewhere for vermin damage! |
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Post by rhyds on May 28, 2021 14:48:40 GMT 1
I'm guessing the intermittent brake pedal switch issue might be the reason for the loss of power. My Focus will, if you hold the brake pedal, cut all fly by wire throttle input and return the engine to idle. Is it possible the brake light switch is being activated long enough to cause this issue?
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Post by Karl on May 28, 2021 19:22:52 GMT 1
Check the BCM plugs for water ingress
they fall over for fun
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Post by valhalla on May 28, 2021 19:45:50 GMT 1
I'm guessing the intermittent brake pedal switch issue might be the reason for the loss of power. My Focus will, if you hold the brake pedal, cut all fly by wire throttle input and return the engine to idle. Is it possible the brake light switch is being activated long enough to cause this issue? The brake pedal switch is the only one not flagging any faults - but you make me think that it might be worth a look to see if that is one of the issues - I've had loads of trouble in the past with the same switch on Landrover products, and it might be the cause of the other two sensors flagging their faults! |
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Post by valhalla on May 28, 2021 19:50:00 GMT 1
Check the BCM plugs for water ingress they fall over for fun As far as I can tell, the multifunction module itself is bone-dry and very clean - certainly no issues sprang to mind when I dropped it down under the glovebox. It would, nonetheless, be a prime suspect for causing a fault like this.
I had a closer look at the ECU pinout diagrams, and I realise I have made an assumption that might be wrong; the multifunction side of the secondary clutch switch, and the ground side of the accelerator pedal, do in-fact go to the ECU, and I'm wondering if my assumtion about the CANbus being the medium by which the ECU recognises the two sensors to be faulty, is wrong. Unlikely, but yet another avenue to try on this car.
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Post by valhalla on May 28, 2021 19:57:40 GMT 1
Methinks I would start by checking all the earth leads and points And elsewhere for vermin damage! That was my line of thought from the word go. The underbonnet fusebox, even if it isn't chewed, is likely to have been awash with mouse urine, and that is a great way to eliminate any good earthing on relay contacts, fuse-blades, and ring-terminals clamped to the inner wing.
I checked the main suspicion for poor earthing, EP2 at the sill/A-post, and all of the contacts are 100%, not a hint of damp or looseness, and less than 0.1ohm back to the respective sensors - even when I did the wiggle-test on all the harness-run I could reach around the back of the dash.
The odd thing is, I was convinced I could see some signs of fraying on the clutch sensor wire, right up behind the dash, but I was wrong; when I got in there with the endoscopic camera this morning, all I could see was OEM-damage, i.e a harness that had been dragged over something sharp when fitted at the factory, and some pretty rookie-looking PVC tape-work, that again turned-out to just be OEM.
It makes it difficult to diagnose problems on modern cars when the "damage" you see is actually built-in by the factory!!
Anyway, I'm stuck in the shop tomorrow, so this is going to have to wait until Monday now.....  |
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Post by valhalla on Jun 1, 2021 20:44:48 GMT 1
Well, looks like I'm in for the long-haul on this one!
Having stripped, cleaned, inspected, greased, reassembled pretty well everything to do with the pedal inputs to the multifunction controller - the car is utterly dead! 
It would be a "squeaky-trouser" moment, were it not for the fact that it now has the failure condition that the owner was trying to explain to me on the phone. Effectively imobilised, and nothing working.
It's the High Speed CANbus that has gone down (nothing talking) and I presently have the CAN breakout box hooked into the diagnostic socket - a serious problem exists on the impedance between the CAN_H and CAN_L lines, such that I'm only seeing circa 17ohm, so that is good (if you are a Diagnostic Engineer) and so-far nothing big has proven to be bad; ABS, multifunction/CJB, SRS, and ECU are all exonerated from guilt.
The car resembles a clown's car right now, as I delve deeper and deeper into the mindset of Uncle Henry, and his inability to locate anything anywhere logical......
Luckily, the problem of impedance is analogue, i.e it doesn't matter that the battery is back off the car again - the readings are just the same. I'm just praying that I'm not measuring the impedance across my CAN breakout box.....  |
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Post by remmington on Jun 1, 2021 21:33:34 GMT 1
Well, looks like I'm in for the long-haul on this one! Having stripped, cleaned, inspected, greased, reassembled pretty well everything to do with the pedal inputs to the multifunction controller - the car is utterly dead! It would be a "squeaky-trouser" moment, were it not for the fact that it now has the failure condition that the owner was trying to explain to me on the phone. Effectively imobilised, and nothing working. It's the High Speed CANbus that has gone down (nothing talking) and I presently have the CAN breakout box hooked into the diagnostic socket - a serious problem exists on the impedance between the CAN_H and CAN_L lines, such that I'm only seeing circa 17ohm, so that is good (if you are a Diagnostic Engineer) and so-far nothing big has proven to be bad; ABS, multifunction/CJB, SRS, and ECU are all exonerated from guilt. The car resembles a clown's car right now, as I delve deeper and deeper into the mindset of Uncle Henry, and his inability to locate anything anywhere logical...... Luckily, the problem of impedance is analogue, i.e it doesn't matter that the battery is back off the car again - the readings are just the same. I'm just praying that I'm not measuring the impedance across my CAN breakout box..... So dropping into the nodes to CAN - with a multimeter thru the DL16 plug - I would expect 60ohm or 120ohm. You are going to to remove all of the CAN nodes off the BUS and starting testing pairs in loops. Then from your looped pairs to earth (chassis) to see if you have any crossovers. If you loop the pairs at the ends where the modules should be - you can actaully map this out in your mind very quickly. Have you no historic faultcodes that will give you a clue where to start. Which needle - which haystack? Where is the gateway? BCM or in the dash cluster? Are you sure the BCM is not wet - damp - moist -  ?? -------------------------------------- I got a 2007 Jeep in the yard at the moment - been in dealers as a non start (ex an AA recovery - supect IMO problem). Dealership did two hours on it - customer declared labour rates too high and towed it out of their yard. I have had lid off BCM - one of the ignition powerhold relays has burnt its way thru the PCB - plus the ignition contactors are burned as well. I am three hours into it - customer may need a magician not a mechanic! I got no coms with anything on this - no IMO boot on dash - but I did get dash idiot lights as they are on another set of good contactors in the back of the ignition barrel. Reckon this chap will be towing at away after paying me more lost labour? |
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Post by valhalla on Jun 1, 2021 23:48:09 GMT 1
Effectively, what I'm doing is the "old fashioned way" which, as you say above, means dropping the nodes off the HS CANbus, one at a time, whilst monitoring the resistance across the pin_6 and pin_14 pair (CAN_H and CAN_L).
So far, I have found the ABS controller to be fine, but that is on the modulator block behind the battery-tray, so the whole lot had to come out again (previously removed so that I could service the fusebox).
The SRS controller (under & behind the handbrake control) was likewise fine - no broken plastic on the centre console either!
The multifunction unit (CJB) under the glovebox cause the resistance to rise a couple of ohms, from 15.4 to 17.2.
Likewise, the ECU in the front left wheelarch (who puts the most important controller on a car in the wheelarch? really?) lifted the resistance from 17.2ohm to circa 19.1ohm.
That tells me :- So far I haven't got to the problem, but I know that my two 120ohm loads are the CJB and the ECU, as each lifted the resistance when they were disconnected, whereas a "normal" HS_CAN input stage would present almost infinite resistance for these purposes. If you parallel resistance of 19.1ohm and 60ohm (effective resistance for 2x 120ohm) then you arrive at a figure of 14.6ohm, and that is within error-bar figures for what I was seeing initially (15.4ohm) allowing for the fact that I haven't nulled-out my multimeter test-leads for this exercise.
I have a printout of the HS_CAN network, but it is the A/D one, so it is a bit generic; some of the nodes do not exist on this car. This helps a lot - not really! I may have to defer to the Ford OEM information which I have online with ALLDATA, but it is hard-going when you just want a summary of the wiring diagrams, preferably in colour. I have the following modules to find tomorrow, after which I will need to start stripping-down the harness;
* Steering module - should be located around the column, and Uncle Henry seems to have picked HS_CAN to communicate with the angle-sensor * Headlamp alignment module - wherever that is * Headlamp switch - I cannot believe this is on HS_CAN, but A/D shows it as-such, and if that is true, heaven only knows why some idiot decided this, but clearly they don't understand the purpose of HS_CAN * Possibly a yaw-sensor in the driver's footwell, but there appears to be a conflict of opinion as to whether this still exists in 2014MY Mondeo - I cannot find it so-far. * Some other minor things like front cruise-control camera (don't think this is fitted) and associated ADAS-type equipment (probably not fitted).
Historic information? Non-existent! as this car has been through two garages already....  which means that I cannot see what started falling-over first, not least nothing on the CANbus will communicate now, although there is a slight chance I can use the order of data as-presented by Autocom when the car first got scanned, but it's a long-shot. Oh yes, Sir, it's the old-fashioned way for this one... |
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Post by remmington on Jun 2, 2021 10:31:29 GMT 1
Note to Vahalla:
I test can networks - "unpowered" - battery off!
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Post by valhalla on Jun 2, 2021 11:29:29 GMT 1
Well, the internet has just gone down locally in the workshop, and that has locked my ALLDATA out 
I had a chance to look through the Ford diagrams and connector information last night - and some of the features mentioned above are not fitted (ADAS and LDW).
All the same, I did a couple of harness-plug disconnections this morning, and still no success, but it rules out the Steering Angle Module at the column, and any chance of Lane Departure Warning module at the front lefthand footwell/A-post.
One thing I forgot to put down on my list, and it immediately triggered some alarm-bells in the back of my mind......I haven't tested this yet, as I need to find the module, but it is almost too coincidental to be true......yes, the good old Power Steering module.
I'm not a betting man, but I wager that when I get to this thing, given its reputation for doing just exactly what I'm seeing here, I will find that the PSM is the culprit. Which is going to be a pain in the derriere alright, as it isn't something I can leave disconnected whilst the owner takes it somewhere else! We will see, watch this space......
Oh, and I nearly forgot, I thought to myself, "How stupid would you look online, more stupid than usual, that's for sure, if you didn't disconnect the CAN breakout box and re-measure pins 6 & 14 directly at the J1962 connector?" Fortunately my face is saved, and the results are much the same.  But on the subject of stupidity, there are some very dangerous videos out there on Mondeo CANbus diagnostics, where everything is incorrect; pinouts, module-allocations across buses, the lot - really quite misleading to the great-unwashed of the social-media world.  I reckon Diagnose Dan would rip it apart if he could be bothered at this stage. |
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Post by valhalla on Jun 2, 2021 17:01:20 GMT 1
Well. despite the best-laid plans of mice and .....mice, as I will expand-upon later this evening, I managed to get enough internet access to carry-on with my job this morning.
I should be a betting man. It was the power steering pump.
No signs of corrosion around or near the connector, and the pump itself is not unbelievably corroded (considering that it is located in the RH wheelarch) but no question about it, and I did an A-B-A-B test with the meter live and the harness near the pump in its normal orientation. As soon as you plug the pump in, CANbus is shorted-out to 19ohm.
Rebuilding the car, but with the steering pump still disconnected, and the HS_CANbus is alive and communicating, just with Inst Pack messaging to say there's a Power Steering fault (as it's disconnected still), the car now starts and runs fine.
This is what happens when cr***y chassis modules are allowed unfettered access to the HS_CANbus; they bring the whole show to a stop, when they should be firewalled away from critical systems (Powertrain) by a central, reliable arbitration module.
I have just got the internet back enough to start researching prices, and timescales, to give the customer the "good news".  |
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Post by valhalla on Jun 2, 2021 22:37:20 GMT 1
No new EPAS units on the shelf with any of the main factors, and the Ford price seems to start at around £850 + VAT + del.
I spoke with the customer this evening, and we have agreed to go with a short-warranty (3month) secondhand unit from a dismantlers-yard that specialises in Fords. The same part number is used across the S-Max and Galaxy range of cars, so plenty of choice for good, used units. It comes in at around £200, but that is a considerable saving on the £550 minimum new price I have found when searching this evening.
The good thing is that I can strip the old electronics down, once the replacement part is fitted, and see why they have failed. I have a sneaking suspicion that there has been an old mouse-nest above the EPAS, such that although it looks OK around the connectors, it has rotted through somewhere obscure and drenched the innards.  |
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Post by valhalla on Jun 7, 2021 23:00:22 GMT 1
Mondeo went out this evening - all fixed with new EPAS, and surprisingly didn't need all the CAN faults clearing on the other modules (again) following the disconnection of the CAN communication connector on the old unit (to move the car around under its own steam).
I'll try and strip the old unit down this week - depends on the workload from the middle of the week onwards.....
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which means that I cannot see what started falling-over first, not least nothing on the CANbus will communicate now, although there is a slight chance I can use the order of data as-presented by Autocom when the car first got scanned, but it's a long-shot. Oh yes, Sir, it's the old-fashioned way for this one...
But on the subject of stupidity, there are some very dangerous videos out there on Mondeo CANbus diagnostics, where everything is incorrect; pinouts, module-allocations across buses, the lot - really quite misleading to the great-unwashed of the social-media world. 
I reckon Diagnose Dan would rip it apart if he could be bothered at this stage.
