PATS error code 16 - 56 Reg Mk2 Focus

[LTIronWolf]

Hi all, it's my first time on the forums so bear with me.

I recently replaced the PCM, Cluster, halo, and the transponder inside my key with a working, tested and coded kit I bought on eBay from a Ford breaker.

When trying to start my car, my immobiliser rapidly flashes and my cluster displays "engine systems fault", and the light soon blinks a 1:6 code indicating a connection issue between the cluster and the PCM. The car refuses to prime or to crank over at all, and I can't read any on-board codes with an ELM327 OBDII scanner connected to my laptop using FORScan, as it fails to connect to the car. I have also tried pressing around the '2' area on the rev counter of the cluster. As the car was originally sent off to a garage to be repaired and was sat there for months, the battery is completely flat so I have to jump the car every single time I want to do something with it.

I have checked the connection on the cluster and it's properly seated, while the PCM connector is on as tight as I can get it with the shearing bolt still in place (there's maybe 5-10mm gap between the base and the connector). I have checked all the fuses to check for breaks, and all of them seem to be intact.

What I find strange is that despite replacing all the coded parts in my Focus with the kit from eBay, the original fob responds to the car as opposed to the new fob that came with the new parts and that is coded to the new parts. Surely the original fob shouldn't be recognised as the original parts coded to the original fob are all gone?

I have no idea what else to try and I've run out of options. If anyone has any ideas or suggestions, please feel free to write back.

[Phil21185]

The only thing I was going to say was whether the cluster connector socket has a broken solder joint to the PCB but your post suggests you've checked for that. 

Nudge @Tdci-Peter 😉

With regards to your fob, if you just mean remote unlocking, that's handled by a different module and not the immobiliser system.

[Tdci-Peter]

3 hours ago, LTIronWolf said:

I can't read any on-board codes with an ELM327 OBDII scanner connected to my laptop using FORScan, as it fails to connect to the car.

Have you checked the CAN bus for continuity? A very simple test is to look for 60 ohms between HS-Can hi & HS-Can lo (pins 6-14 in the diagnostic connector).

There is a 120 ohm resistor between the lines in the IC, and another one in the PCM. So if the PCM is connected to the IC it will read 60 ohms, if there is a break then 120 ohms. Unplugging the big connector in the engine bay fuse box will break the CAN bus, so can help check which end the problem is if you get 120.

2006 is the classic year for the Focus IC problem, did the replacement IC come from a car of the same age?

The remote control fobs are coded in the BCM (aka GEM or passenger fusebox), and are almost entirely separate from the PATS. The PATS chip in the key is a little glass or plastic slug, not connected to the remote control pcb.

The failure to connect with Forscan suggests either the PCM got damaged at some stage, or is not being powered up properly, or is not connected via the CAN bus to the diagnostic connector. Forscan will connect to the PCM even if the IC is missing, I believe.

I assume the kit was from a very similar car, same engine especially.

 

[LTIronWolf]

38 minutes ago, Tdci-Peter said:

Have you checked the CAN bus for continuity? A very simple test is to look for 60 ohms between HS-Can hi & HS-Can lo (pins 6-14 in the diagnostic connector).

I have not yet - I need to get my hands on a multimeter first, but once I do I'll give it a try. If the CAN bus has no continuity, would that explain my inability to connect with OBDII, and potentially my error code 16?

 

40 minutes ago, Tdci-Peter said:

2006 is the classic year for the Focus IC problem, did the replacement IC come from a car of the same age?

Yes, give or take. My car is a 56 Reg, whereas the IC and the other parts came from a 55 Reg car (according to the tag that came on the new key), so it's the same mark and similar age.

 

42 minutes ago, Tdci-Peter said:

The remote control fobs are coded in the BCM (aka GEM or passenger fusebox), and are almost entirely separate from the PATS. The PATS chip in the key is a little glass or plastic slug, not connected to the remote control pcb.

Oh, I see - so this shouldn't create an issue in terms of PATS deactivating? I'm guessing I'll need to use my original key for central locking and the new key to disable PATS. If I get my car fixed, is there any way I could clone the PATS code from the new to old key, and the central locking from the old to new key? Preferably using FORScan

 

43 minutes ago, Tdci-Peter said:

the failure to connect with Forscan suggests either the PCM got damaged at some stage, or is not being powered up properly, or is not connected via the CAN bus to the diagnostic connector. Forscan will connect to the PCM even if the IC is missing, I believe.

I assume the kit was from a very similar car, same engine especially.

 

The parts I bought were taken from a working Focus that was broken for parts, and were tested for working condition before being sent, so I should hope all the parts are working so that I can rule out a parts fault. it sounds like it's potentially a CAN bus issue - it would explain the error code 16. Was the CAN bus a common problem for Mk2 Focuses as well?

 

45 minutes ago, Tdci-Peter said:

Forscan will connect to the PCM even if the IC is missing, I believe.

Apparently it should still work despite PATS being enabled and immobilized, so I think you're right.

 

46 minutes ago, Tdci-Peter said:

I assume the kit was from a very similar car, same engine especially.

 

Yes - it came from a 55 Reg car (mine's a 56 Reg), and both cars are 1.6 Petrol, so it should be a match.

[LTIronWolf]

1 hour ago, Phil21185 said:

The only thing I was going to say was whether the cluster connector socket has a broken solder joint to the PCB but your post suggests you've checked for that. 

Oh, I was referring to the clip/connector that connects to the back of the IC - I haven't opened up and checked the exposed circuit board. I know how to solder but I'm not very good, so I'm apprehensive to try in case I accidentally ruin my (sort of) working IC.

[Phil21185]

Well, I know a common problem which tends to result in the immobiliser kicking in is a dry solder joint on the connector to the board itself.  As I say, @Tdci-Peter is very knowledgeable on these matters and may be able to help you further, but if you search around on here, you'll find a good amount of info.

Apparently all that needs doing is the solder reflowing on the pins, which basically just means heating it up gently until it melts just once.

[Tdci-Peter]

2 hours ago, LTIronWolf said:

it sounds like it's potentially a CAN bus issue - it would explain the error code 16. Was the CAN bus a common problem for Mk2 Focuses as well?

The common fault was exactly that, the pins the carry the CAN bus on to my IC had gone dry joint. It gave error code 16, and 120 ohms on the resistance test.

Stripping down the IC is a bit fiddly, careful force is needed to remove the needles from the very thin spindles, and to unbend the clamps round the LCD. But from your main symptom of not making contact with the ECU, it looks to me like the fault now may lie elsewhere. A 2005 IC may be ok, it looks like only one batch, though a big one, was affected. So I would advise against stripping the IC at least until the resistance test is done.

Forscan can programme PATS on the Mk2 Focus. Once you get the immobiliser unlocked with the new key, it should be possible to add your old key to the stored list. The car must have at least two key codes stored in it before it will start, and can store up to 8, I think. One slight worry is that it may need to have both keys already known to it inserted before it will add a third (though the Forscan page says only one known key is needed, I have just seen). If that was the case it should be possible to erase all keys, and then programme in the 2 you have. I am no expert on this procedure, I have not tried it as it is not something to experiment with. If you erase all keys, then one of the keys you have can not be recognised, it will stay immobilised.

A write up on the procedure is here:

http://forscan.org/forum/viewtopic.php?f=6&t=839

An alternative is to locate and transfer the PATS capsule. On some keys, especially after-market ones, this is easy, but on some original Ford ones, it seems to be moulded in.

But until you can get Forscan to make contact with the ECU, nothing is going to work!

 

 

[LTIronWolf]

3 minutes ago, Tdci-Peter said:

The common fault was exactly that, the pins the carry the CAN bus on to my IC had gone dry joint. It gave error code 16, and 120 ohms on the resistance test.

I'll try the resistance test first before any risky solder work on my IC - do you have a diagram for the pins on the OBDII port? 

Let's say that the resistance test fails and it is the CAN bus - what would I do then to fix the problem?

4 minutes ago, Tdci-Peter said:

Forscan can programme PATS on the Mk2 Focus. Once you get the immobiliser unlocked with the new key, it should be possible to add your old key to the stored list. The car must have at least two key codes stored in it before it will start, and can store up to 8, I think. One slight worry is that it may need to have both keys already known to it inserted before it will add a third, though in that case it would be possible to erase all keys, and then programme in the 2 you have. I am no expert on this procedure, I have not tried it as it is not something to experiment with. If you erase all keys, then one of the keys you have can not be recognised, it will stay immobilised.

I'll try and get the car running before I start fiddling with keys - nor can I do right now (thanks to the connectivity problem) nor is it practical in case I can't fix my car. 

As for the inability to connect - I'm using bootcamped Windows on a MBP 2016, using a USB-C to USB-A connector (I don't have a regular Windows laptop available at the moment) for my modified ELM327 cable. Could this potentially be a cause for the issue? I assumed it would work just fine, as Device Manager doesn't have any yellow exclamation marks next to "USB Serial Device (COM3)" and my connection settings are set to auto in FORScan.

I think the original PCM has both keys stored from the original car - there wasn't any mention of the PCM being touched beforehand. In that case, I should be fine to re-program both of my keys? I'd rather not try and transfer PATS modules between keys in case I accidentally break one.

[LTIronWolf]

Oh, and another thing - is there any way to lower the mileage on my car using FORScan or another program? I remember the original value (76,384 miles) whereas the new IC reads 91k miles - I'd like to alter it so it's truer to value and doesn't look questionable during my MOT test.

[Tdci-Peter]

9 minutes ago, LTIronWolf said:

Could this potentially be a cause for the issue? I assumed it would work just fine, as Device Manager doesn't have any yellow exclamation marks next to "USB Serial Device (COM3)" and my connection settings are set to auto in FORScan.

I think the original PCM has both keys stored from the original car - there wasn't any mention of the PCM being touched beforehand. In that case, I should be fine to re-program both of my keys?

If Forscan can not communicate with the ELM, then it will say so. A log file I have when I tried connecting with the ignition off gave this:

(OK) [22:34:03.796] Connection to adapter has been established on COM1
(OK) [22:34:03.796] Adapter:  ELM327 v1.5
(ERR) [22:34:05.515] Unable to connect to vehicle. Please make
sure the ignition key is ON and try again

As you can see, it did contact the ELM on a COM port, and this is the computer driver part. The fail was when the ELM then tried to contact the vehicle.

Has the ELM you have ever been tested with a working vehicle? Faulty ELMs are very common. They all come from China, and the quality varies a lot. It can be tried on almost any Ford modern enough to have the socket.

Mileage: No it can not be lowered. Only by rather dodgy and expensive specialists.

Edited May 19, 2018 by Tdci-Peter
Add note

[LTIronWolf]

1 minute ago, Tdci-Peter said:

If Forscan can not communicate with the ELM, then it will say so. A log file I have when I tried connecting with the ignition off gave this:

(OK) [22:34:03.796] Connection to adapter has been established on COM1
(OK) [22:34:03.796] Adapter:  ELM327 v1.5
(ERR) [22:34:05.515] Unable to connect to vehicle. Please make
sure the ignition key is ON and try again

As you can see, it did contact the ELM on a COM port, and this is the computer driver part. The fail was when the ELM then tried to contact the vehicle.

Has the ELM you have ever been tested with a working vehicle? Faulty ELMs are very common. They all come from China, and the quality varies a lot. It can be tried on almost any Ford modern enough to have the socket.

Mine's pretty much the same - my ELM is v1.4, but I'm sure that's just an insignificant detail. I haven't tested it on another vehicle but I'll try it if it's compatible.

This is the one I bought - https://www.ebay.co.uk/itm/Modified-ELM327-USB-Ford-Elmconfig-Focccus-Forscan-Focus-Smax-Mondeo-Kuga-CMax/162068198073?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m2749.l2649 

Is it compatible with just Ford vehicles, or any vehicle as long as you have the software to go with it? I have a 2015 Honda HR-V I have access to which I could try, but I don't know if it would interface.

[Tdci-Peter]

2 minutes ago, LTIronWolf said:

Is it compatible with just Ford vehicles, or any vehicle as long as you have the software to go with it? I have a 2015 Honda HR-V I have access to which I could try, but I don't know if it would interface.

The ELM327 itself is a generic CAN bus to serial port interface, and also includes many of the other protocols used in OBD standards. So it will work on other cars, as long as the computer software will recognise it. Forscan itself may be able to read basic OBD2 information from other cars, as this is governed by international standards, so should be compatible.

All manufacturers must include the basic OBD2 functionality, but they also use the diagnostic interface for a great many things specific to their models as well, like PATS.

[LTIronWolf]

1 hour ago, Tdci-Peter said:

The ELM327 itself is a generic CAN bus to serial port interface, and also includes many of the other protocols used in OBD standards. So it will work on other cars, as long as the computer software will recognise it. Forscan itself may be able to read basic OBD2 information from other cars, as this is governed by international standards, so should be compatible.

All manufacturers must include the basic OBD2 functionality, but they also use the diagnostic interface for a great many things specific to their models as well, like PATS.

I'll give the cable a try on another car and see if that's the part at fault. Once that's ruled out, I'll try the resistance test on the OBD port. If it still doesn't work, my last resort is to re-solder the pins on the IC, isn't it?

I'm away until the 30th, so I'll get back to you when I'm next back to my car. If it is a CAN bus issue, what would the fix be?

[Tdci-Peter]

On 5/20/2018 at 12:39 AM, LTIronWolf said:

I'll give the cable a try on another car and see if that's the part at fault. Once that's ruled out, I'll try the resistance test on the OBD port. If it still doesn't work, my last resort is to re-solder the pins on the IC, isn't it?

I'm away until the 30th, so I'll get back to you when I'm next back to my car. If it is a CAN bus issue, what would the fix be?

A CAN bus is just a twisted pair of wires, physically. It starts at one terminus, the PCM for the Focus HS-CAN bus, winds through various parts of the car, with spurs off to various modules (bus stops) on the way, and ends at another terminus, that is the IC for the HS-CAN bus. The 120 ohm terminating resistors are at the termini, PCM & IC. The diagnostic connector is the first bus stop after the IC.

After the diagnostic connector, next break is one of the big connectors down in front of the passenger door, then typically the ABS unit, then EHPAS (Steering), then the big connector in the engine bay fuse box, then the PCM. (Different car variants will have different routes.)

You have the fact that the IC can not communicate with the PCM (Flash Code 16), and also the the diagnostic connector can not communicate with the PCM (Forscan fails). If both of those are true, then the fault lies not in the IC, but in the section between the diagnostic connector and the PCM, or in the PCM or its connector.

So until the resistance test & ELM check are done, it is hard to say what the next step might be.

 

 

[LTIronWolf]

@Tdci-Peter Finally back, so I can carry on working on the Focus.

One thing I considered earlier, but didn't think about it too much as I thought it wouldn't be an issue - is my connector not seated low enough? If it's not making contact, that would explain everything - the OBD2 port and the IC. I've attached a few pictures: I've tightened the original shearing bolt as much as I can using a hammer and chisel, but there's still a small amount of space until it's finally flush, and the connector has some play in it can be rocked forward and backward.

My fear is that if the CAN bus is responsible, it's most likely a burnt-out wire or connection somewhere. The way the original IC broke in the first place is after I reconnected the positive terminal (wasn't very smart of me at the time), it sparked and it led back to the IC which was corrupted. So there could be a communication error because there's a broken or melted link. What do you think? I'll do the resistance test soon, just waiting for another car to jump the Focus with.

[LTIronWolf]

I just did the resistance test on pins 6 and 14 - I got a reading of 61.2-61.3 ohms, so it doesn’t look like it’s a CAN bus issue which is a relief. What are my next steps - re-solder the connector on the IC?

[LTIronWolf]

About to reflow my solder joints for the IC, and I noticed some sort of weird residue inside the cluster - it’s like a weird putty or chewing gum mixture that’s covering the airbag light. Any idea?

[Tdci-Peter]

1 hour ago, LTIronWolf said:

I noticed some sort of weird residue inside the cluster - it’s like a weird putty or chewing gum mixture that’s covering the airbag light. Any idea?

That definitely looks deliberate. I have seen things like that before, a garage can not find or fix an elusive problem, so they cover up the light to make the owner think its been fixed, or a dodgy owner might do it to get it through an MoT.

With those connectors, usually the connection depth is much greater than the gap you have left, so it should be making contact. But the fact that it rocks about, and will not go fully home makes me wonder if there is a bent over pin inside there.

With the IC disconnected, I would be tempted to try and see if Forscan can still make contact with the ECU. The 61 ohms reading does rather put suspicion on the ECU or its contacts. It might be worth re-checking the fuses in the engine bay fusebox, at least any connected to the ECU.

I guess the car is too far away from a socket to use a charger. On a Focus, it is also possible to power up the car (but not start it!) using a suitable regulated voltage charger with a cigar lighter adapter plugged into one of the power points, even with the battery removed. If it was diesel you might need to remove the glowplug fuse, as these come on with ignition & draw huge current.

 

[LTIronWolf]

14 hours ago, Tdci-Peter said:

That definitely looks deliberate. I have seen things like that before, a garage can not find or fix an elusive problem, so they cover up the light to make the owner think its been fixed, or a dodgy owner might do it to get it through an MoT.

I'm a little bit concerned to be honest - I'm hoping/guessing it was done by the owner when the IC was in its original car, and maybe the breaker didn't check the IC for it before sending it off. In the meanwhile, I've reflowed the solder joints and I'll try connecting it today and see how it goes. Fingers crossed I haven't killed my IC 😁

14 hours ago, Tdci-Peter said:

With those connectors, usually the connection depth is much greater than the gap you have left, so it should be making contact. But the fact that it rocks about, and will not go fully home makes me wonder if there is a bent over pin inside there.

I didn't notice any bent pins when I first received the PCM, but if I'm out of options I'll unplug it and inspect it. There's still a bit of space as there's only so much tightening I can do without removing the bolt completely - I'm tempted to drill out the bit and install my own bolt if I can't do anything else. The rocking is more like a seesaw motion: I can wiggle it up and down on both sides, but I think that's more because the bolt isn't tightened fully and there's extra room, so it has the freedom to move. 

Is there any way to test the PCM while it's unplugged to determine if it's faulty in any way? Do you reckon it's worth trying for me to connect my original PCM and see if it gives me a different error code, so we can rule out if the PCM is faulty?

15 hours ago, Tdci-Peter said:

With the IC disconnected, I would be tempted to try and see if Forscan can still make contact with the ECU. The 61 ohms reading does rather put suspicion on the ECU or its contacts. It might be worth re-checking the fuses in the engine bay fusebox, at least any connected to the ECU.

I can give it a try before I connect the IC and test it - how can the IC removed have an impact on it connecting? I've checked the fuses in the engine bay (at least the ones I can see through), and all of them seem to be intact. 

15 hours ago, Tdci-Peter said:

I guess the car is too far away from a socket to use a charger. On a Focus, it is also possible to power up the car (but not start it!) using a suitable regulated voltage charger with a cigar lighter adapter plugged into one of the power points, even with the battery removed. If it was diesel you might need to remove the glowplug fuse, as these come on with ignition & draw huge current.

It is too far annoyingly, and I don't have anything of the sort to power it through the cigarette lighter. The battery currently sits around 2v, and every single time I jump the car to work with it and disconnect the cables, it will sit around 5.5v. However, the battery's voltage seems to drop fairly quickly - you can noticeably see the voltage dropping while reading with a multimeter - is the battery ruined from being drained and jumped?

[Tdci-Peter]

1 hour ago, LTIronWolf said:

Do you reckon it's worth trying for me to connect my original PCM and see if it gives me a different error code, so we can rule out if the PCM is faulty?

Yes, for sure. If there is no IC, or the wrong IC, it will give all sorts of error messages about PATS problems & invalid CAN bus readings, but that would be a huge improvement on dead silence!

I can not think of any very useful way to test a PCM out of the car. Thinking a bit more about it, removing the IC for a test is unlikely to help, it provides the termination resistance for one end of the CAN bus, which is needed to make the bus work properly. The CAN bus driver chips are very robust, they have to meet tough specifications. But I was thinking maybe a fault in the IC could be forcing the CAN bus to an invalid level, and preventing communications with the PCM. But that is a long shot.

The 61 ohms test shows the bus is connected to both the IC and the PCM, and on to the resistors in both of them.

If the battery has sat at 2v for any length of time, it will be wrecked. No Lead-acid batteries (including Calcium, AGM, EFB, etc etc) like being left discharged. Getting the right, stable voltage on the car is the essential first step in diagnosing any electronic faults. I am not sure how long it takes a PCM to boot up after a full power down. They normally sleep with a standby 12v supply still on. So that could be a contributory factor in the problems.

 

[LTIronWolf]

1 minute ago, Tdci-Peter said:

Yes, for sure. If there is no IC, or the wrong IC, it will give all sorts of error messages about PATS problems & invalid CAN bus readings, but that would be a huge improvement on dead silence!

My first test will be with the reflowed IC - I'll see if that fixes anything. If not, I'll try swapping out PCMs and see if I at least get a different response. If it still gives me error code 16, then is it possible that it's a voltage issue?

3 minutes ago, Tdci-Peter said:

I can not think of any very useful way to test a PCM out of the car. Thinking a bit more about it, removing the IC for a test is unlikely to help, it provides the termination resistance for one end of the CAN bus, which is needed to make the bus work properly. The CAN bus driver chips are very robust, they have to meet tough specifications. But I was thinking maybe a fault in the IC could be forcing the CAN bus to an invalid level, and preventing communications with the PCM. But that is a long shot.

The 61 ohms test shows the bus is connected to both the IC and the PCM, and on to the resistors in both of them.

Either way, I'll test the OBD port and see if I can connect both with and without the IC - I'll let you know the results are.

5 minutes ago, Tdci-Peter said:

If the battery has sat at 2v for any length of time, it will be wrecked. No Lead-acid batteries (including Calcium, AGM, EFB, etc etc) like being left discharged. Getting the right, stable voltage on the car is the essential first step in diagnosing any electronic faults. I am not sure how long it takes a PCM to boot up after a full power down. They normally sleep with a standby 12v supply still on. So that could be a contributory factor in the problems.

Yeah, it's sat flat while it was at the garage for several months, so I imagine it's probably dead - luckily for me, I only got it in November so it's covered by its 5 year warranty. If I'm not mistaken, the PCM sleeps and isn't active unless the voltage is high enough? I'll try waiting until the battery is charged to 12v then try starting it.

[LTIronWolf]

@Tdci-Peter I've run all my tests, and no luck so far.

First off, I tried to connect with FORScan with my IC unplugged - no luck. Plugged my IC back in after resoldering the connection, it worked same as before (didn't ruin it with my soldering 😂) and FORScan still doesn't connect, nor did the car crank or start. I received the same error code 16, even when I swapped in my original PCM - no error codes about mismatching. I put the original PCM back in, and let the car sit for 10-15 minutes while being jumped, and it didn't seem to wake the PCM up (if that's even a thing).

Then I checked all the fuses in the engine bay related to the PCM - no signs of burning out or damage, so no luck there. I checked all the fuses related to the IC in the fusebox under the glove compartment - also no luck. I also checked the resistance on the OBD port after removing all 3 fuses one by one - it still showed 61 ohms despite all fuses removed, which I find bizarre. I'm at an absolute loss and I don't know what to do now. Any ideas?

[JW1982]

Before going further just replace the battery first. The Focus MK2/MK2.5 has a protection to disable most critical electronic systems when the battery voltage is not sufficient. It is a known fact that the PCM (and also several other modules) do not communicate when the battery voltage is below approximately 10 Volt. 

The instrument cluster can easily be tested outside the vehicle. Just connect it to a suitible 12 Volts DC power source and connect the HS-CANbus pins of the connector to the appropriate pins of the ELM327 interface. In this configuration the instrument cluster will power up. It will throw a lot of errors and DTC codes but you know at least that the instrument cluster is working.

 

Why did you replace the PCM? If I read correct the instrument cluster is defective. In this case you only have to replace and reprogram the instrument cluster. This is pretty easy and can completely be done with the Forscan program.  

Replacing the PCM introduces a different problem. You have to verify that the new PCM has the correct software for your engine. The PCM can be the same but the software may be completely different between 2 modelyears. In worst case scenario this can result in engine damage. If the PCM does not have the correct software it needs to be reprogrammed with the correct software.

Apart from this the PCM also has a configuration file that includes a number of settings/options of the car. For example tyre, size, type of transmission (and also gear ratio's) and whether the car has cruise control or not. When replacing the PCM the configuration als needs to be correct.

 

Replacing the instrument cluster, PCM and keys as a complete set of a different vehicle is only plug and play if the vehicle where the parts come from is 100% identical to the vehicle the parts are installed in. In all other cases additional reprogramming is always necessary.

[Tdci-Peter]

19 hours ago, LTIronWolf said:

I put the original PCM back in, and let the car sit for 10-15 minutes while being jumped, and it didn't seem to wake the PCM up (if that's even a thing).

Then I checked all the fuses in the engine bay related to the PCM - no signs of burning out or damage, so no luck there. I checked all the fuses related to the IC in the fusebox under the glove compartment - also no luck. I also checked the resistance on the OBD port after removing all 3 fuses one by one - it still showed 61 ohms despite all fuses removed, which I find bizarre.

Wilco, above, has clarified a few things that had been worrying me, and maybe I should have said more. Testing the PCM in particular while connected to another battery via jump leads is likely to cause problems. Also it is a good point about the compatibility of PCMs between cars, though you have now gone back to the original PCM.

Is there something which is draining current from a battery, and pulling down the system voltage below 12v while being jumped? If you do fit a new battery this is the very first thing to check, or that one will get flattened too.

The 61 ohms reading needs no fuses or battery power, there are no fuses in the CAN bus itself, it is just a 2 wire connection from PCM to IC, with various stopping off points at other modules on the way. It does go through several connectors on its journey though.

The "secret dash test" (press & hold the mileage reset stalk while turning on ignition) can be used to further test the IC, and will even provide some error codes, possibly. There are lots of posts about this test, if you have not tried it.

Listening for any clunks and clicks from the engine while turning ignition on & off can tell if there is any sign of life from the PCM, though with no communication to the IC and the immobiliser active, it may not do much.

 

[LTIronWolf]

@JW1982 and @Tdci-Peter Thank you for the replies - I'm sorry I only just saw your posts.

On 6/1/2018 at 3:40 PM, Tdci-Peter said:

Wilco, above, has clarified a few things that had been worrying me, and maybe I should have said more. Testing the PCM in particular while connected to another battery via jump leads is likely to cause problems. Also it is a good point about the compatibility of PCMs between cars, though you have now gone back to the original PCM.

Is there something which is draining current from a battery, and pulling down the system voltage below 12v while being jumped? If you do fit a new battery this is the very first thing to check, or that one will get flattened too.

The 61 ohms reading needs no fuses or battery power, there are no fuses in the CAN bus itself, it is just a 2 wire connection from PCM to IC, with various stopping off points at other modules on the way. It does go through several connectors on its journey though.

The "secret dash test" (press & hold the mileage reset stalk while turning on ignition) can be used to further test the IC, and will even provide some error codes, possibly. There are lots of posts about this test, if you have not tried it.

Listening for any clunks and clicks from the engine while turning ignition on & off can tell if there is any sign of life from the PCM, though with no communication to the IC and the immobiliser active, it may not do much.

 

I'll look into getting the battery replaced when I come back from Holiday in September. I'm off tomorrow, so there's no use in replacing the battery as it'll simply go flat again. I guess that would explain why I'm getting error code 16 - the PCM refuses to wake up due to unstable battery voltage? As for the dash test, I'll give it a try and see if it gives me any codes - hopefully it'll give more insight and explain what's going on. Would the codes be similar to DTCs which you read from FORScan, or are they proprietary Ford codes?

On 6/1/2018 at 8:03 AM, JW1982 said:

Why did you replace the PCM? If I read correct the instrument cluster is defective. In this case you only have to replace and reprogram the instrument cluster. This is pretty easy and can completely be done with the Forscan program.  

It was lacking a cluster as the original cluster completely died. I had no idea it was a case of just replacing a cluster and being able to re-program it, I'll see about doing that once I first replace the battery.

On 6/1/2018 at 8:03 AM, JW1982 said:

Replacing the PCM introduces a different problem. You have to verify that the new PCM has the correct software for your engine. The PCM can be the same but the software may be completely different between 2 modelyears. In worst case scenario this can result in engine damage. If the PCM does not have the correct software it needs to be reprogrammed with the correct software.

Apart from this the PCM also has a configuration file that includes a number of settings/options of the car. For example tyre, size, type of transmission (and also gear ratio's) and whether the car has cruise control or not. When replacing the PCM the configuration als needs to be correct.

Probably a good thing I haven't successfully fired up the engine yet, otherwise I would've risked damaging the car. So if I understand correctly, my best bet is to swap in the original PCM and re-program the IC to match the car? Is there any way to save the current config on the IC, in case I don't manage to program it correctly and need to go back? One slight issue is that the current IC has a reading of 91k miles, whereas my original IC (and the data stored in the original PCM) read 76k miles, so there's going to be a mismatch and it may not work. FORScan's mileage adjuster only increases mileage, and can't decrease it.