ECU and BCU compatibility

MGB281 wrote:

I don’t mean to take this thread off topic but since Roverlike posted the following;
”in case of second half of 2003 onwards MGTF is equipped with Pektron BCU. That unit is paired with engine ECU or Engine Management System. Remote fobs are paired with BCU. All of that can be done woth PScan. However do not forget you need barcode with remote fob if you want to pair it with Pektron
BCU”
I presume the link to the ECU is to cut the power supply or earth so the engine won’t start?
If so could you retain the immobiliser with an aftermarket ECU?
 

Original engine ECU is set to question 5AS or BCU for dedicated paired code. If that code is not present, engine ECU will not work, it will be immobilised. 
However if engine ECU is remaped or aftermarket ECU is used and that questioning sequence for paired code is removed you will be able to use engine ECU without immobilisation as it is not present.
Not to be confused, you still needs remote fobs since 5AS or BCU is still present and it will do its remaining functions of prevention but not the engine immobilisation.

Delbourt wrote:

Thank you for clarifying that. I have looked in the WSM I have and there is nothing that gives that detail that I can see. In Roger Parker's book "MGF & TF Restoration Manual" there is reference to the 5AS.
I have grasped the importance of the need to match engine ECU to the 5AS.
What I am struggling to identify is anything to do with the connection between the door locks and the 5AS. Clearly there is one.

I am aware that the Pectron unit tends to need the relays associated with locking and unlocking the door locks. So with that thought I am considering what relationship the 5AS has with the door locking arrangement and specifically for the following reasons.

When the door button is going rapidly up and down (machine gunning) it is the locking motor that is driving that action.
The three micro switches in the lock mechanism would not seem to have a bearing on that. One determines if the key has been used, one determines if the door is closed and the other if the internal quadrant has reached its intended position (being uncertain if the switch is normally open or closed I can't comment on its status when the quadrant within the lock is in the unlocked position).
If we start with a door closed and locked condition it would be reasonable to think that the motor will continue to drive the lock open if the fob signals the 5AS to unlock the door until something breaks or the associated clutch continues to function. As the quadrant can only swing between a relatively small arc there is nothing that would permit it to continue to rotate. With that said something else has to tell the motor to change direction and that can only be the 5AS.
If the system requires a micro switch to change condition from open to closed or closed to open and that switch has failed surely the 5AS will continue to send power to the locking motor to continue to rotate in the selected direction. As the quadrant reaches its end position the clutch will slip but it will not drive the motor the other way unless something in the 5AS tells it to.
So what is it? Any ideas will be gladly accepted. It is for this uncertainty that I am considering changing the 5AS

I think that you are looking into wrong direction here. 5AS and BCU are doing central locking function. Both are sending signals for motor direction on all locks simultaneously. So if directon of lock motor would be changed from one direction to the other by 5AS or BCU it would be done on both doors in the same time, and not only on one door.
If I understand correctly problem is on one door only, so whatever it is it is done locally on that door only.

How long signal is active for one direction of door lock/unlock I am not sure at this moment. Would need to investigate if that information is available somewhere.

To clarify: -
Initially the experience of “machine gunning” was observed on both doors. As a consequence the doors were locked using the key only until the driver’s door lock was replaced (it was assumed that the driver’s door dictated what the passenger door did or performed).
During the process of preparing for removal of the driver’s door lock a further “machine gunning” was experienced before the battery was disconnected. It is not what instigated that, possibly as a consequence of having the key in my trouser pocket and squashing it as I leant into the car.

Investigation of the removed lock prompts further questions (see other topic relating to superlock). Simply put none of the three micro switches appear to directly affect any “message” to the 5AS when seeking to unlock.
In order to “machine gun” the basic door lock motor needs to rotate in both directions (there is nothing to drive either the door button or the door lock key electrically).
So somewhere within 5AS there must be something to tell it to reverse the motor’s direction (and as there is nothing to restrict movement from superlock to unlocked superlock must be irrelevant in this context).
So my theory is that the 5AS must be failing.
Ill be delighted if there is another explanation.

5AS failing is very rare situation and must say that failed central locking in case of 5AS is possible in case of fried printed circuit board which I've seen, but never saw 5AS failing in such circumstance to give "machine gun" problem. Always it was door lock problem, not 5AS problem.

Do not forget that one of the switches provide information of sill up or down and the other of the switches provide information of drivers door closed or not.

Drivers door sill can be put up or down by hand and by that you will trigger central locking or unlocking of both doors. So if that switch is not behaving as it should it will trigger 5AS to react.

If 5AS is failing I would expect for new lock to behave in same manner with "machine gun" because 5AS is failing and it is not replaced. Only door lock is changed.

I accept that 5AS has a higher sense of reliability than Pektron.
Let’s just consider the situation for a moment. Prior to locking the car there was no movement of the key (nor prior to attempting to unlock with the fob), so the plunger operating that micro switch was not disturbed and it stayed put.
After examining the mechanism there is no apparent deficiency (wear) in the arm that tells the system that the door is closed (and if there was what difference would it make?).
The operation of the fob to lock the car and the subsequent motor movement of the quadrant within the mechanism sweeps the quadrant past a micro switch (it is not known if that switch recognises the first locked position or the superlocked position.
However, when the fob is engaged to unlock the door it must surely send a signal to the 5AS to open the lock. 
Logically there is only one micro switch involved that is the one swept by the quadrant and I cannot see anything that would change the current flow direction through the motor to make it turn one way then the other unless the 5AS switches the current.
If I’m wrong I’ll be pleased for someone to explain why/how.

Roverlike wrote:

MGB281 wrote:

I don’t mean to take this thread off topic but since Roverlike posted the following;
”in case of second half of 2003 onwards MGTF is equipped with Pektron BCU. That unit is paired with engine ECU or Engine Management System. Remote fobs are paired with BCU. All of that can be done woth PScan. However do not forget you need barcode with remote fob if you want to pair it with Pektron
BCU”
I presume the link to the ECU is to cut the power supply or earth so the engine won’t start?
If so could you retain the immobiliser with an aftermarket ECU?

 

Original engine ECU is set to question 5AS or BCU for dedicated paired code. If that code is not present, engine ECU will not work, it will be immobilised. 
However if engine ECU is remaped or aftermarket ECU is used and that questioning sequence for paired code is removed you will be able to use engine ECU without immobilisation as it is not present.
Not to be confused, you still needs remote fobs since 5AS or BCU is still present and it will do its remaining functions of prevention but not the engine immobilisation.


My 2003 TF (Lucas fob) has now an ECU sent by K-Maps, not the original one (happy with the remap, BTW)
Does it mean the immobilisation has been erased?
I was thinking of having it suppressed, it would be a nice addition if it has already been done
 

Red110 wrote:

Roverlike wrote:

MGB281 wrote:

I don’t mean to take this thread off topic but since Roverlike posted the following;
”in case of second half of 2003 onwards MGTF is equipped with Pektron BCU. That unit is paired with engine ECU or Engine Management System. Remote fobs are paired with BCU. All of that can be done woth PScan. However do not forget you need barcode with remote fob if you want to pair it with Pektron
BCU”
I presume the link to the ECU is to cut the power supply or earth so the engine won’t start?
If so could you retain the immobiliser with an aftermarket ECU?


 

Original engine ECU is set to question 5AS or BCU for dedicated paired code. If that code is not present, engine ECU will not work, it will be immobilised. 
However if engine ECU is remaped or aftermarket ECU is used and that questioning sequence for paired code is removed you will be able to use engine ECU without immobilisation as it is not present.
Not to be confused, you still needs remote fobs since 5AS or BCU is still present and it will do its remaining functions of prevention but not the engine immobilisation.


My 2003 TF (Lucas fob) has now an ECU sent by K-Maps, not the original one (happy with the remap, BTW)
Does it mean the immobilisation has been erased?
I was thinking of having it suppressed, it would be a nice addition if it has already been done

 

You can ask K-Maps if that part of code interrogation is removed.

Delbourt wrote:

I accept that 5AS has a higher sense of reliability than Pektron.
Let’s just consider the situation for a moment. Prior to locking the car there was no movement of the key (nor prior to attempting to unlock with the fob), so the plunger operating that micro switch was not disturbed and it stayed put.
After examining the mechanism there is no apparent deficiency (wear) in the arm that tells the system that the door is closed (and if there was what difference would it make?).
The operation of the fob to lock the car and the subsequent motor movement of the quadrant within the mechanism sweeps the quadrant past a micro switch (it is not known if that switch recognises the first locked position or the superlocked position.
However, when the fob is engaged to unlock the door it must surely send a signal to the 5AS to open the lock. 
Logically there is only one micro switch involved that is the one swept by the quadrant and I cannot see anything that would change the current flow direction through the motor to make it turn one way then the other unless the 5AS switches the current.
If I’m wrong I’ll be pleased for someone to explain why/how.

When fob sends signal to 5AS lock will be turned into unlock position and microswitch you are describing will be in unlock state. However in the same time sill is taken into up position where second microswitch is placed, isn't it? That second switch is disturbed at that time. At that moment proces of getting lock to unlock state is over and 5AS is not providing any signal any more.

However this microswitch which is disturbed by the sill is the one that sends signal to 5AS that sill changed position from up to down or vice versa. If that switch is playing and is changing state without being told to do so, then it will start sending 5AS information that sill is moved up and down and to send current into door lock to activate it for closing and then opening and then closing etc.

In your description you did not take this second switch into account which is inevitable disturbed with unlock operation by the sill movement.

And then, since sill microswitch is interconnected with third microswitch, that microswitch also changes state.

So, with one action all three microswitches are disturbed at once and change their respective state. 

Thank you for the reply and continuing to engage in this discussion.
There is no micro switches associated with the door button . When the door button is pressed down or pulled up it acts (indirectly) on the quadrant. Once the quadrant rotates through its arc the associated switch will change its state, and as far as I can see there is nothing to tell the system that it has completed the required movement other than possibly the switch associated with the key (the lever associated with the key locates in the quadrant with some degree of freedom of movement.

If that micro switch associated with key movement ‘sticks” in a position telling the 5AS to lock the door I can foresee a situation where the 5AS does not know what to do and potentially changes the instruction to lock the car.
In that scenario the quadrant motor will change direction to lock and if the 5AS has a timer used to ensure that the quadrant moves to unlock the car it would be possible to see a condition where the system locks/unlocks rapidly.
A lot probably depends on how the 5AS is programmed.
In my view the micro switch telling the system that the door is shut plays no part in this it is simply there to warn the driver that a door is not closed properly.

I will stop responding to this thread and I will stand corrected if you tell me that you do not have 2 connectors coming from you drivers door actuator: 6-way plug and 2-way plug.

6-way plug:
Pin 1: Lock motor direction wire 1 Orange wire 
Pin 2: Drivers door open microswitch Brown/Red wire (microswitch 2) - used in cojunction with boot swith tied with microswitch 1
Pin 3: Sill down from microswitch Black/Pink wire (microswitch 1)
Pin 4: Lock/Superlock motor direction wire 2 Pink wire
Pin 5: Superlock motor wire Brown/Pink wire
Pin 6: Drivers door open microswitch Pink/Grey wire (microswitch 3)

2-way plug
Pin 1: Sill up from microswitch Black/Orange wire (microswitch 1)
Pin 2: Ground/Earth Black wire

All these wires (except ground wire) goes directly to 5AS, or they come from 5AS respectively.
What I would do is use a multimeter and check which microswitch provides signal to which wire and under which case.

If you have these 2 connectors then you are not seeing something correctly.

Please do not get me wrong, I am not proving anything here, I am merely trying to provide correct information for the community and help owners to see things in correct way. If I am wrong in any statement, I will stand corrected, as I said.

Apologies if this is duplicated in some way I was trying to read and write at the same time.
i confirm that the door lock in question has two connectors. One with 6 pins and one with 2. The 5AS is located behind the console and below the heater controls.
At present the car has both door locks responding to key and fob with the exception that it will not respond to a request to superlock. It did prior to the lock change earlier in the year.
I can’t comment on wire colours as the door cards are in place.

I can report that the 6 wires in the lock are coloured blue, pink, green, red, and purple. The pink, green, and purple go to the motors.
The other connector colours are black and grey.
I think that the white and the black are associated with movement of the key.
I think that blue and the black are associated with door status i.e. door open/closed
I think that red and possibly grey are associated with the quadrant micro switch.

The uncertainty is due to the difficulty in operating the switches whilst holding continuity meter probes against the pins for test purposes.and I think there is a broken joint between at least one pin and its wire within the cable connector, and it possible that the faulty connection was responsible for interrupting and confusing the 5AS if the thesis in the responses above are correct.
If I had to guess I think the pin in the middle row at the bottom of the connector (where bottom has the two plastic engagement alignment features) is the most probable source of interruption and again if I’m right that would be the quadrant micro switch. I was reasonably confident that the slide operated switch (that would recognise key operation) was functioning satisfactorily when I bench tested it.

Hope this is of some use to all concerned.

A bit of an update.
I have two door locks available to test (one I removed following a “machine gun” experience and another that I aim to fit as I can’t get superlock working with the one in the car.
So with the connectors lightly gripped in a workbench I tested for continuity between pins with the door locks available open then closed and locked/unlocked.
What I could not confirm with repeatability was the presence of continuity between the pins associated the micro switch that comes into play when using the key (or the same switch that would be activated when the quadrant is moved electrically).
When testing I felt that sometimes there was continuity and sometimes not.
So perhaps that switch is used to indicate one part of the sequence and if it’s continuity switches on/off that would presumably confuse 5AS and create the “machine gun” condition.
Just a thought even if I can’t see a simple solution