Repairing the factory fitted Bosch immobiliser fitted to UK 2.0l and 2.5l 
Ford Probes
  Last updated 03/08/01 
 
michael.crummy@ntlworld.com   
fast URL http://clik.to/fordprobe  
 
  
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  The Problem - symptoms of failure and cause
  Repair of the immobiliser
  Circuit board pictures
  Testimonials
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  Forum 
  
 
FAME AT LAST - this site visited by FORD

"Our LOCAL FORD GARAGE were interested to see your 
website, as they are frustrated about the cost of 
dizzy replacements for Probe owners."

A direct quote from Sharon-Elaine on the Ford Probe 
Owners Club UK Forum 21 June 2001
So FORD dealers come to this website for information on 
repairing FORD cars ! Interesting ... Eh ? 
"The fix was sickeningly easy when you consider the 
alternative of buying more dizzys and how much 
Ford are making on replacing all those dizzys"

JERRY 28/06/01 		 
"They ( FORD ) did suggest I take it to a Mazda dealer or 
pay £1000 and they would replace everything....
...with your help it took 1 HOUR TO FIX and NO COST"

ROGER DORSETT 29/07/01
 
The Problem...
 
The Bosch immobiliser fitted to UK Ford Probes is subject to failure due to excessive current flowing through some of the solder joints - these high currents occur when the distributor components start to fail. Chances are that if you've had to replace the distributor or its components, then the immobiliser will also have sustained some damage, and will continue to plague you with embarrassing cut-outs.

The symptoms of immobiliser failure can be identical to "ignitor unit" failure and are often mistakenly identified as such, resulting in needless expense for a new distributor. Failure can lead to intermittent engine cut-out, subsequently resulting in loss of power steering and braking power, which is potentially catastrophic if travelling at any speed. It can also manifest itself as a failure to start after switching off the engine. It is therefore potentially dangerous at worst and at best can be acutely embarrassing. In my case the car had an uncanny knack of cutting out at traffic signals and would only restart after a few minutes - very frustrating !! 

It is also interesting to note in hindsight that my car would always cut out at almost the same places every time - going round a particularly tight bend for example...I suspect the chassis flexing was enough to break the already stressed solder joints.

Recent information received indicates that a sharp slap to the passenger side of the centre console can sometimes bring the immobiliser back to life temporarily by rattling the defective solder joints enough for them to make contact.
 
This particular model of immobiliser is known to have been fitted to some or all 1994 16V and 24V models but may have been fitted in other years. The author accepts no responsibility for loss or damage arising from the use of this information. All repairs are carried out at your own risk.

I have been led to believe that E.S. Alternators in Glasgow, who supply relatively cheap replacement distributors for the Ford Probe, will also repair the immobiliser. 
If you are unfamiliar with soldering it is highly advisable to entrust the repair to them or somebody with soldering experience.
   
E.S Alternators      (0141) 776 3689
Unit 7
Eastside Industrial Estate
Kirkintilloch
Glasgow
G66 1QQ
 
It really works... testimonials from some very happy Probers 
Due to the ever increasing number of emails I am receiving concerning 
the immobiliser fix and to make it easier to find the actual repair 
information I have moved the "It really works" section HERE 

If you find any of the information supplied useful or interesting then 
please take a few moments to sign my guestbook...Thank You
 
 

Or why not exchange experiences in the NEW Forum

And here it is...the information you were really looking for

Removal of immobiliser unit

1) Locate the immobiliser. It's behind the centre console at floor level. No need to remove the centre console, just the 2 small side panels 
(1 screw, 1 clip). The immobiliser is attached to a metal plate secured by 2 rivets and 2 star screws.

2) Remove metal plate - best to have the right tools - a right angled adaptor for the screw bit will help - the star screws are tight and awkward to get at. Drill out the rivets and withdraw metal plate. 

( I have to admit that I ended up having to hacksaw through the bracket to get the immobiliser out ... it was 22.30 and I was doing it by torchlight... and I was determined to get it out that night ! Brute force and ignorance sometimes works )

3) Unbolt immobiliser from steel plate and disconnect the cable connector.

Repair procedure

4) The immobiliser is plastic and is held together by 3 screws - undo these to reveal the circuit board. There are two big black boxes on the board (one bigger than the other) - these are the switching relays -  the solder joints underneath them become damaged due to the high current flow which occurs during distributor component failure. This causes them to lose contact with the board either sporadically or permanently. 2 solder joints on my board looked distinctly dodgy - dull and rough instead of shiny and smooth. I removed the solder using a soldering iron and solder sucker, then re-soldered them. For good measure I also re-soldered as many of the other joints as I could, although it appears from correspondence received that the two joints noted below are the only ones involved in the failure.  
See "IT REALLY WORKS" for examples.

5) Re-assembly is the reverse of the above as they say in all good Haynes manuals. Replace the rivets with new ones. The pop rivets and the rivet gun are not expensive items.

6) Reconnect and start engine and enjoy a few more years of fun motoring with a big smile on your face since you've just saved yourself approx £250 on a new immobiliser from FORD.

Here are some pictures of the suspect joints on the circuit board which I have encountered. 
These may not be the only solder joints at fault, so blanket re-soldering of as many of the other
 joints as possible is recommended.
 

One of the joints on my immobiliser board - reflected light shows up a distinct ring around the 
joint - this joint has been damaged by excessive current and intermittently loses contact with 
the board causing engine cut-outs.
 

This one looks distinctly suspect as well. The brown discolouration is flux contained in the 
solder which has been released by overheating.
 

The big picture - the location of these joints on the board.
 
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