Changing battery in TF Round remote fob - not working!

[speakmanrp]

Help!

Have a 2004 MG TF Anniversary model, neither remote fob will work after battery change.

About 6 weeks ago I had a second set of keys in my pocket and it must have pressed one of the buttons on the fob for a long time and drained the battery. When I went to unlock the car, nothing. Second fob worked ok at this time.
Changed the battery in the fob, but still would not work, but I had a 2nd working one so stupidly didn't do anything about.

Last week the 2nd fob failed - again another set of keys in my pocket............
Again changed the battery, but this time read the manual. With no battery in I pressed each key for 5 secs to discharge and then put the new battery in. Unlocked the car with the key and then pressed the lock button more than 4 times - nothing. Repeated on the other fob, still nothing.

So nothing but the EKA at the moment (which fortunately works) - any help would be really appreciated

[Rob Bell]

Hopefully something really simple!!! Just wondering: the batteries you've put into the fobs are in good condition with good charge? We bought AA batteries from Asda recently for the clocks around the house only to discover that half of them were duds.

Check them with a multimeter, and similarly check to see whether the fob's circuit board is getting power.

[speakmanrp]

Thank you Rob, they are brand new Cr2032 3V batteries, but it would be worth checking. I'll dig out my trustee voltmeter and make sure this evening.

[Rob Bell]

You never know! I was astonished to find in-date batteries as flat as proverbial pancakes when I checked them...

BTW do you have the 22-digit bar codes for your two key fobs? If the originals, you may find the code numbers stuck inside your user manual or service book. These may be necessary to recode them later if the SCU has lost "connectivity" with them for what ever reason.

More on the SCU can be found here: http://mgf.ultimatemg.com/group2/DIY/se ... /index.htm

[austingarages]

Are the keys to your TF kept on the same bunch of keys to another car by any chance?

[nigelandjo]

Have you re-synced the fobs to the car after changing the battery? IIRC you press the unlock button 5 times with the fob beside the car ~ the procedure is in the handbook.

[speakmanrp]

Hi,

Thank you all for you replies.

I checked the battery and on board voltage last night on both fobs, 3.04V volts - so it's not the batteries.

Normally the fobs and keys for the MG are on their own ring, the only other keys being front door and garage.

I have followed the procedure to re-sync the fobs, but with the car door unlocked and pressing the lock button 4 or more times. Thats what it says in the RAVE workshop manual I have:

The remote handset can be re-synchronised to the alarm ECU by ensuring that the driver's
door is unlocked with the key and pressing the remote handset lock button at least four times
in quick succession. The system will respond by locking the doors, indicating that the remote
handset and alarm ECU are now synchronised.

NigelandJo I will try your method tonight when I get home.

Failing that I think it will be time to call in an Auto Locksmith or send the Pektron and fobs off to one of the online services.

[austingarages]

The SCU has become known to be unreliable for various reasons however, the handsets are normally very reliable. If the TF keys are kept on the same bunch as say an MG ZT or BMW derived car with similar electronic immobiliser, then the TF handset can become corrupted - but only when key is used in the other car! If the keys are stored together then it's not a problem. If the TF handset has become corrupted in this way it is irreversible and a new one will have to be coded to the SCU. In a worst case it can also corrupt the SCU, although I have not experienced this. There was a period MG Rover buliten issued to dealers that reflects this info.
A few things to check are the battery contact that clips onto the side of the circuit board, maybe try disconnecting the car battery for a few seconds and then trying the above re-sync process. Does the CDL still operate from the key? And can you hear a two tone beep from the console area with the ignition turned on (when engine is immobilised)?

[colintf]

The SCU has become known to be unreliable for various reasons however, the handsets are normally very reliable. If the TF keys are kept on the same bunch as say an MG ZT or BMW derived car with similar electronic immobiliser, then the TF handset can become corrupted - but only when key is used in the other car! If the keys are stored together then it's not a problem. If the TF handset has become corrupted in this way it is irreversible and a new one will have to be coded to the SCU. In a worst case it can also corrupt the SCU, although I have not experienced this. There was a period MG Rover buliten issued to dealers that reflects this info.
A few things to check are the battery contact that clips onto the side of the circuit board, maybe try disconnecting the car battery for a few seconds and then trying the above re-sync process. Does the CDL still operate from the key? And can you hear a two tone beep from the console area with the ignition turned on (when engine is immobilised)?

thats scary, many thanks for the tipoff

[Rob Bell]

Thank goodness most of us have good, reliable Lucas systems

[speakmanrp]

Thank you all for your help.

After trying many different solutions, it looks like I do need new fobs, which with a bar code, are not cheap

However the garage I use have told me how to make the Emergency Key Access code work every time, so while I wait for the new fobs, I'm using that.

The handbook is not clear , but the way to get the EKA to work every time is as follows:

1. Enter the EKA as per handbook.
2. The door will be left locked after the last EKA code digit is entered.
3. Unlock the car door Immediately - do not delay or it will not work
4. The alarm light on the dashboard will stop flashing rapidly and stay on for 1 second then go out until you open the door.
5. Wait 5 minutes and the immobiliser is switched off and you can start the engine.

Hope this helps someone else out - maybe a good idea for all you 2004 and later MGTF owners to try your EKA before the fobs stop working

[Rob Bell]

Thanks for the update - but why have the fobs stopped working?

[Softly~Softly]

My 2003 TF fobs both started playing up last night, in the dark, thanks for all the tips

[austingarages]

Thank you all for your help.

After trying many different solutions, it looks like I do need new fobs, which with a bar code, are not cheap

However the garage I use have told me how to make the Emergency Key Access code work every time, so while I wait for the new fobs, I'm using that.

The handbook is not clear , but the way to get the EKA to work every time is as follows:

1. Enter the EKA as per handbook.
2. The door will be left locked after the last EKA code digit is entered.
3. Unlock the car door Immediately - do not delay or it will not work
4. The alarm light on the dashboard will stop flashing rapidly and stay on for 1 second then go out until you open the door.
5. Wait 5 minutes and the immobiliser is switched off and you can start the engine.

Hope this helps someone else out - maybe a good idea for all you 2004 and later MGTF owners to try your EKA before the fobs stop working

I can add point 6. After the 5 minute delay, the engine has a 10 minute window in which it can be started.

Thanks for the update - but why have the fobs stopped working?

My thoughts exactly - normally they are very reliable.

[speakmanrp]

Hi,

Yes point 6 should be added, you get 10 mins, this also applies if you turn off the engine but do not lock the car - you get 10 minutes or you have to go through the EKA procedure again.

As to why the fobs stopped working - Back to my original post on this thread, there were items in my pocket that pressed the buttons on the fobs repeatedly, this puts the fobs out of sync with the Pektron unit, apparently its not possible to re-sync them even with a T4. So new fobs is the only answer - unless somebody else know better.

On a passing thought, as the Lucas unit seems to be more reliable than the Pektron, has anyone with a 2004 or newer TF removed a Pektron unit and replaced it with the Lucas unit and older BCU? I suspect it's not possible due to wiring changes, but again you never know......

[richandpaula]

Scarey stuff!
Sounds like I was quite lucky the other night when changing the battery in one of our fobs then, didn't follow any procedure - just opened the fob and put a new battery in!

[austingarages]

On a passing thought, as the Lucas unit seems to be more reliable than the Pektron, has anyone with a 2004 or newer TF removed a Pektron unit and replaced it with the Lucas unit and older BCU? I suspect it's not possible due to wiring changes, but again you never know......

Nothing is impossible as they say, but it would require a complete wiring loom swap as the SCU replaced the Lucas 5AS alarm unit, red multifunction unit, driver's window lift module and the main fusebox is different...

[Mike H]

Just wondering - the replacement batteries were the recommended type 2032 were they?

I know if someone who fitted 2016's in error - the same dimensions and also 3 volt (his OH said they looked the same when she bought them), and they failed to operate. He refitted with 2032's and all was instantly well.

[speakmanrp]

Hi,

Yes both lots were definitely the CR2032 type. The fobs were transmitting, a friend bought around a wireless detector which blinks an led to show transmission, of course it does not tell what's being transmitted...........

[speakmanrp]

On a passing thought, as the Lucas unit seems to be more reliable than the Pektron, has anyone with a 2004 or newer TF removed a Pektron unit and replaced it with the Lucas unit and older BCU? I suspect it's not possible due to wiring changes, but again you never know......

Nothing is impossible as they say, but it would require a complete wiring loom swap as the SCU replaced the Lucas 5AS alarm unit, red multifunction unit, driver's window lift module and the main fusebox is different...

Thank you for this, it confirms that I'll need to live with this and make sure that I look after the fobs better in the future.