1 hour ago, ssmith93 said:

then I will do as you suggest and purchase either of the following two tomorrow:

Option 1

Option 2

Either of those will be fine 👍

14 hours ago, unofix said:

Either of those will be fine 👍

So I rang ford parts this morning, really helpful.

For my car he said it should be DS71-12A650-XD. What is currently in the car is H/W: DS71-12B684-XD. And P/N: JV6A-12A650-AA.

It seems the number he has given me is an amalgamation of the two H/N and P/Ns. When I search I cannot find anywhere a 'DS71-12A650-XD', all I can find is what is in the car already. I also tried another fords parts department and they gave me the same.

I have in the meantime ordered This, which should be here on monday. I've read various info about programming the new PCM, including bits about it needing to be programmed to two keys and all sorts. I am hopeful it is as simple as you have said which is just installing the as-built data from https://www.motorcraftservice.com/asbuilt.

So whilst I have this PCM on order (should arrive monday), I've continued with investigations!

 

I monitored a couple of sensors on live view today - Photo attached.

Charge Air Temp Bank 1 Sens 1 (Red Trace)

CACT Voltage (Turquoise Trace)

When at idle or usual driving, both behave normally. Under fault conditions (engine warm, speed >40mph, foot on the accelerator), I see huge voltage spikes down to 0v.

It makes sense that this could be a ground fault (as has been suggested) with this behaviour, but peculiar that these spikes only happen under certain circumstances.

I think it does make sense to change the sensor as part of my trial and error approach, as this will help to exclude the sensor as the cause. Now I cannot seem to find a IAT or CACT for this car, is it built into the MAP or boost pressure sensor or something?

 

Thanks

 

1 hour ago, ssmith93 said:

I think it does make sense to change the sensor as part of my trial and error approach, as this will help to exclude the sensor as the cause. Now I cannot seem to find a IAT or CACT for this car, is it built into the MAP or boost pressure sensor or something?

As said earlier in the thread, the public catalogues don't cover 2018 unfortunately.

My best guess based on the earlier 2.0 TDCI would be that the IAT is in the MAF sensor.  And the charge air temp is in the MAP sensor (which is used to measure boost pressure on a turbo engine). 

MAP used to be right on the front of the engine, just about where the Y shaped intake branches meet above the throttle body.  But I'm not sure if your engine uses a different intake manifold to those ones.

@TomsFocus thanks.

So I tried unplugging the MAP sensor which I is on the manifold inlet above the throttle body.

With this unplugged interestingly I got a reading of 5v from the charge air temp voltage, when I plug it back in the the charge air temp reading goes back to 2.25v or thereabouts.

Plugged in or not, I cannot get it to read 0v like in the fault readings.

I also tried the very crude method of monitoring the charge air temp voltage whilst wiggling around the wiring loom a lot. No issues at all and I cannot get it to drop to 0v.

Frustratingly, this would seem to make the wiring to this sensor a slightly less likely issue.

 

I will do the same in a bit with the MAF sensor unplugged to see what the IAT readings to, which should help us find whether that is in the MAF.

 

Update:

IAT bank 1 sensor 1 is on the MAF sensor (next to the air box)

IAT Bank 1 sensor 2 & Charge Air Temp are on the MAP sensor (on top of the intake manifold)

Neither fault to 0v when unplugged, so the fact that my problem involves a sensor faulting to 0v continues to trouble me!

Have ordered a replacement MAP sensor to rule out.

 

 

The following might be helpful for anyone replacing a PCM / ECU on a similar model using FORScan.

I had a chance to fit the replacement PCM yesterday morning. Exact same delphi model, exact same part number.

• Installed into the car, went to turn the car on and initially got quite a few codes, I should have saved them but I didn't remember to at the time, there were some which were definitely from the previous car it was installed in.

 

• Cleared the codes, turned back on - engine still wouldn't start, various codes including that the PCM has a different VIN and says that it is arguing with the primary and secondary immobiliser.

 

• So I tried module initialisation/relearn vehicle data - I think this sorted out the VIN number, but still no engine start, same immobiliser issue.
• Then tried Module Configuration (asbuilt) and loaded my asbuilt data - no change.

 

• So I thought I would try the PATS function on FORScan - and it worked!

 

• I did another module initialisation and now everything was talking, and the car starts up and drives without any codes or arguments.

I didn't have time to give it a road test to see if this has solved my problems, but on Friday of this week I will be able to do that and will report back!

So the latest on this:

• I purchased a replacement PCM (£120)and fitted it. Coded it to the car using FORScan. Took it for a drive and for 10-15 mins I had no issues - thought ahhh maybe it's done the job! sadly not. issues recurred...
• Similar sets of codes, almost always a P06A6 and the most common additional ones are the MLPS 'y' position and 'x' position circuit high/low etc and also the other MAP and IAT codes mentioned previously in this post.

I think i'm now left with the wiring harness as the next most likely thing unfortunately. I have been speaking to a bloke on facebook who replaced his on the driveway and he said it wasn't impossible.

The harness in my car is a KV4T-14B060-MCB, however I can only find a KV4T-14B060-MCA available. As I understand it the final letter is just a minor revision, however I was wondering if anyone might know if the MCA one will fit my car. I will make a separate question thread about that but I just wanted to give the latest updates on my issue...

1 hour ago, ssmith93 said:

The harness in my car is a KV4T-14B060-MCB, however I can only find a KV4T-14B060-MCA available

24 minutes ago, unofix said:

That's a hard one to call.

If you had the MCA harness on your car then you then you could 100% replace it with the MCB because the changes are always backwards compatible.

However doing it the other way around, it probably will be OK but there is that very small chance that the older revision harness might just be missing some extra wire.

Personally I'd chance it, if you can't find the correct version.

 

1 hour ago, unofix said:

 

Apologies but I have made a bit of an error.

I wrote the numbers down the other day when I was looking and I think I got them a bit mixed up... I should have been looking up KV4T-12C508-MZB. (I can find exact replacements for that)

I will double check in the morning as I wouldn't want to mess this one up ha!

What a wally....

Do you have any experience replacing the engine harnesses with the engine still in the car, I imagine as long as I go one bit at a time removing old and installing new connectors like for like as I go I should be ok.

im having the same issue have ordered the sensor and will be delivered tomorrow will let you know the outcome

 

15 minutes ago, Phantom76 said:

im having the same issue have ordered the sensor and will be delivered tomorrow will let you know the outcome

 

what sensor have you ordered? are you having only a single fault code come up or do you get multiple like me?

 

you can have a read here 

 

Did you cut open the wiring harness like I said to check for damage? 

21 minutes ago, iantt said:

Did you cut open the wiring harness like I said to check for damage? 

Todays job before I consider ordering a replacement harness to try. Will update when i've done so. The MLPS is one of the first things that comes off the harness so I should be able to open it up all the way to the MLPS which seems to be the most consistent fault code to be present when limp mode is triggered (albeit it doesn't actually cause limp mode by itself).

Am I sensible to presume that the issue would most likely be somewhere between the nearest sensor playing up (MLPS) and the PCM?

2 hours ago, ssmith93 said:

Todays job before I consider ordering a replacement harness to try. Will update when i've done so. The MLPS is one of the first things that comes off the harness so I should be able to open it up all the way to the MLPS which seems to be the most consistent fault code to be present when limp mode is triggered (albeit it doesn't actually cause limp mode by itself).

Am I sensible to presume that the issue would most likely be somewhere between the nearest sensor playing up (MLPS) and the PCM?

Can be anywhere there's a bend in the harness to be fair. I did think earlier as the pcm had been replaced before hand, that hadn't fixed the fault so that's why it was  up for sale. Forgot to pre warn before you bought another. 

1 hour ago, iantt said:

Can be anywhere there's a bend in the harness to be fair. I did think earlier as the pcm had been replaced before hand, that hadn't fixed the fault so that's why it was  up for sale. Forgot to pre warn before you bought another. 

Well it made sense to try it as a possible solution as the replacement PCM was a simple fit and only £120 and I can actually return it if needed.

 

Hopefully in the next few hours I will be able to report back any findings with the harness. I clearly wont be able to take the whole thing apart but I'll start with the route from the MLPS sensor to the PCM

@iantt I had full intentions of examining the wiring loom properly today.

Unfortunately these were disrupted by my loosing of the locking wheel nut - I have never had good experiences with LWNs and always vowed to change any to normal ones - stupidly I haven't done that yet on this car....

Still searching for where i've put this stupid key..

In the meantime I have found the code of the wiring harness on the car which is K1DT-12C508-MZB. Spoke to ford who advised that the harness it should have is KV4T-12C508-MZA .

A bit confused as to why I have a different harness to the one ford say is for the car, not sure if this would make a difference...

I will examine the existing harness for damage as and when I can.

I had a issue with corroded pins on pcm and plugs wich plugs in to pcm. I have the same engine in my Focus. I bought Haynes diagnostic step by step online and it gives you pin out and step by step guide how to test each sensor and wiring for it. Like I'm Mike case I had few codes for 3 different sensors and all 3 on the same line of power supply (+5v and ground). I'll try to download pin out of pcm.

Forgot to mention,  sometimes some of the pins not gripping well and contact is not reliable 

That's my PCM and condition of the pins. Pin out to follow. 

Here. Before I started on the car I printed all pinouts on paper and highlighted what I needed to check. Under wheel arch I think it's 2 or 3 earthing points .

@Zen23 thanks for all of this.

Where did you find the details about which of your things shared the same ground and +5v? when you say that "3 different sensors and all 3 on the same line of power supply (+5v and ground)."

 

I would think from the issues I have had I would be looking at the following from those pinout readings:

- A14 / A29 / A33 / A48 (L3 - MAF/air temp)

- A26 / B21 / B30 (L4 - MAP/air temp)

- A28 / A47 / A65 / A9 (S19 - Gear switch) - possibly if this is the MLPS

- B21 / B6 (Turbo pressure solenoid / MAP & Air temp / throttle control motor)

 

Interestingly none of the pins seem to correlate with the MLPS? (gearbox lever position sensor which is on the gearbox)

Right, I took pictures of my printouts it's a simple diagrams and hopefully you can read my writing. But you already figured out MAP, Throttle body and Turbo solenoid positioning sensor on the same power supply line. And what I suspect after looking at diagram if connection is poor on power supply when throttle body operates its drawing current and puts itself and other 2 sensors out of range/fault. 

When I took it ford they done smoke test and replaced Throttle body which didn't fix anything. But ideally should of load tested the wiring. 

The same with MAF, it's sharing the same line with other 2 sensors.