3 replies to this topic

[GTRMikie]

I have a Paul Smith mpi. Usually the immobiliser needs one press of the unlock button on the fob to disarm the immobiliser. Recently it has required two presses of the unlock button. When this is done, the red indicator led flashes a number of times, just like it does when the immobiliser is first armed, but the car would start. Today I went to start the car and it was dead, just like the immobiliser had not disarmed. Battery is fully charged and I have new fob battery on order, but any suggestions as to what the problem might be are welcome.

[slidehammer]

My advice would be, if you are intending to do the work yourself you need to buy something like Pscan as this will read error codes for alarms and immobilisers. Also you will need something like this to recode the new fob to the immobiliser unless you pay a vehicle locksmith to do it for you. It could be a faulty immobiliser or fob, you can also link a new immobiliser to the ECU with this software, so that would mean being able to get a second hand one and recode it. The software is about £170.00 but I would imagine a locksmith will be half that price to recode a fob. It also does all the usual engine and airbag fault code reading.     

[Quinlan minor]

This might help:

"

Don’t Panic, Captain Mainwaring!

There’s some cause for alarm.

 

Although I’m extremely fond of my 1998 MPi, it has one irritating feature which, even after six years, still catches me out from time to time.

 

The alarm/immobiliser, an MG Rover 5AS, has what’s called “passive arming” and it operates by disabling the fuel pump. The effect is, in my opinion, potentially quite dangerous!

 

Picture the scene: you pull up to pick up the wife/kids (in your designated role of transport manager) on the side of the road, switch off and wait. Eventually they turn up, get into the car, you start up, pull out into a gap and the engine cuts out! “Damned immobiliser!”

 

To restart, you must push the arm button on the remote,  then wait twenty seconds or so until it resets itself.

 

Twenty seconds seems an eternity when a truck is bearing down on you!

You then hit the disarm button, restart the engine, and get on your way, grumbling like Muttley from ‘Wacky Races’.

 

Recently my problem was made considerably worse, when the ability of the transmitter fob to disarm became erratic.

 Sometimes it would take fifteen or twenty presses to work and, invariably, the more I was in a hurry, the longer it took.

 

Unfortunately, only one fob came with the car when I bought it, so I couldn’t tell where the fault lay, with the transmitter or receiver.

 

I changed the battery, it seemed to work until an early start Monday morning.

I checked the fob circuit board and found a dry joint. Re-soldered it and it seemed to work until …..

Took the receiver out, checked it for damp (a common problem caused by a leaking windscreen) no problems found. Replaced it, seemed to work. You’re probably ahead of me by now.

Unfortunately, the way the 5AS works is by sending a discrete code to the engine management unit, so you cannot simply bypass  the bloody thing!

 

After some research, I was lucky to find Paul Brown at Technozen Electronics.

Paul has all the kit and will supply two new fobs coded to your 5AS ECU at a very reasonable price.

He can, also, disable the passive arming, match your 5AS to a replacement engine ECU. R Clone your 5AS details if you want to fit the "later" type 5AS to add indicator flash on arm/disarm, or reprogramme the Engine ECU to remove the immobiliser.

Normally, you send the unit with any old fobs to him, by post, and he will return them to you within one working day. As my car is a ‘Daily Driver’, he was kind enough to sort mine out while I waited, parked on his drive.

I now have a spare fob (I’ve had a spare set of keys cut, too), the range on which is better than my old one ever was.

Paul can be contacted:

[email protected]

 44 Meadowview

Bevendean

Brighton

East Sussex

BN2 4NF

07527 877995

 

It might be possible , if arranged, to have it done when you visit Brighton on the L2B or Donut Run if post poses problems for you."

 

 

[GTRMikie]

Thanks for the replies, but the panic is over! The non start was due to a loose connection on the starter solenoid wire, nothing to do with the immobiliser, I probably disturbed it when I removed the oil filter during an oil change. The erratic key fob operation was fixed when I installed a new battery.