How JustAnswer Works:

  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.

Ask Greg Szczygiel Your Own Question

Greg Szczygiel
Greg Szczygiel, UK Car Mechanic
Category: Car
Satisfied Customers: 12
Experience:  Vehicle technician and electrician currently working in reputable independent garage in UK. Fully acredited ATA diagnostic technician.
82566532
Type Your Car Question Here...
Greg Szczygiel is online now

- What causes an immobiliser to stop arming? I can start

Customer Question

- What causes an immobiliser to stop arming? I can start the engine without the fob - the red led does not illuminate

Submitted: 2 years ago.
Category: Car
Expert:  Greg Szczygiel replied 2 years ago.
Greg Szczygiel :

I'm Greg.

Greg Szczygiel :

Could you tell me how long did you own this car?

Greg Szczygiel :

My apologies, I have just noticed your Already tried message.

Expert:  Greg Szczygiel replied 2 years ago.
Our chat has ended, but you can still continue to ask me questions here until you are satisfied with your answer. Come back to this page to view our conversation and any other new information.

What happens now?

If you haven’t already done so, please rate your answer above. Or, you can reply to me using the box below.
Expert:  Greg Szczygiel replied 2 years ago.
What is the brand and model of aftermarket immobiliser on You defender?
Thanks
Customer: replied 2 years ago.

.

Sterling Excel

Expert:  Greg Szczygiel replied 2 years ago.
Ok,It looks like your immobiliser control unit or wiring is at fault.
This type of control unit should automatically arm after 60 secondes after turning ignition off.
Have you changed any optional settings of the unit since it worked ok?
Customer: replied 2 years ago.

Greg - I would not know how to adjust or what those options were.

Thanks

Expert:  Greg Szczygiel replied 2 years ago.
Ok no worries,leave it with me while I'm checking operating manual of your immobiliser I presume you haven't got one ?
Customer: replied 2 years ago.

The manual I have assumes "normal" operation. No troubleshooting.

Thanks again

Expert:  Greg Szczygiel replied 2 years ago.
Yes, It should include optional or personalisation settings which can be changed by the user.
Customer: replied 2 years ago.

Only to add a new fob or delete an existing fob. No details scenario where the immobiliser is not arming

Expert:  Greg Szczygiel replied 2 years ago.
This unit should automatically arm after ignition off, do you know where is it connected to permanent power supply (positive) and ground ?
Can you tell if the unit itself is powered ?
And finally do you know which circuits does it cut ?
It looks like it thinks ignition is on all the time.
Can you check orange wire when ignition is off there should be 0 volts.
Customer: replied 1 year ago.

Greg - Thanks answers - but they have not answered the question. - Like I said - the unit has been working month - and suddenly stopped working - I asked - what causes this scenario - all has been suggested is I start pulling and prodding wires - which as a non mechanic / car wiring specialist I am less than qualified

So - the unit thinks the ignition is on all the time - what cause this to happen - is it a radio frequency or a disruption of wiring due to perhaps it being cold. Is there any way of programming the unit using software?

Sincerely

Derrin

Expert:  Greg Szczygiel replied 1 year ago.
Derrin,
The following conditions cause immobiliser systems to stop arming:
1.Immobiliser unit did not receive request to be armed.
The request comes from the remote (fob), ignition switch, time after ignition off which normally is no more than 60 secondes.
On your type of immobiliser even if you don't press the fob button or the fob is away of the car it must still arm automatically.
I presume this is how it was before it failed.
You didn't make any changes of the unit's configuration so this is how it should be anyway.
2.Immobiliser unit has failed internally and it needs replacing.
So in order to start troubleshooting, full wiring check must be done.First and most important thing to check is voltage on the wire connected to ignition switch.
Voltage of this wire tells immobiliser unit to arm because user has switched ignition off, removed key from ignition switch and left the car.From this moment immobiliser unit waits up to 60 secondes and arms automatically to protect against theft by cutting ignition, starter or anything else depending how it has been installed.
My suggestion was to check the voltage on the orange wire.
If it is +12v after ignition off it means that following fault can exists:
Short circuit in wiring, orange wire is shorted to other wire with permanent voltage of +12v.If this is the issue, immobiliser unit will than ignore any signals from the fob.
Water ingress into the unit or wiring of the car.
Internal fault of the hardware or software which you can fix only by replacing the whole thing.
There is no way of programming or reprogramming of this unit.
Frequency from other sources like radios or magnetic fields are possible but only in certain locations where vehicle is parked.
My strong advice to you is to book your vehicle with good, independent garage with the experience on aftermarket immobilisers.
I'm happy to assist you further and I strongly believe this is the answer to your question.
Greg Szczygiel, UK Car Mechanic
Category: Car
Satisfied Customers: 12
Experience: Vehicle technician and electrician currently working in reputable independent garage in UK. Fully acredited ATA diagnostic technician.
Greg Szczygiel and other Car Specialists are ready to help you
Customer: replied 1 year ago.

Unusually - left couple of days (not started) and the unit has resumed normal operation. Thanks again insightful knowledge

Expert:  Greg Szczygiel replied 1 year ago.
You're welcome, If you need any further assistance let me know.
Greg

What Customers are Saying:

 
 
 
  • 9 dollars, 2 hours of my time, and I drove away. Your diagnosis was right on the mark. Thank you so much. Phil
< Previous | Next >
  • 9 dollars, 2 hours of my time, and I drove away. Your diagnosis was right on the mark. Thank you so much. Phil
  • Lurch. Thank you very much. I had real doubts about this website but your promptness of response, quick followup and to the point answer with picture was incredible. Charles
  • As a single woman, I really appreciate an excellent and affordable opinion.
    Thank you Geordie, I will not hesitate to contact justanswer in the future!
    Sue
  • Another great insight to what may be the problem. I will have my mechanic take a look at it tomorrow. Thanks again, Frank...you do indeed know your stuff. Jim
  • I would (and have) recommend your site to others I was quite satisfied with the quality of the information received, the professional with whom I interacted, and the quick response time. Thanks, and be sure that I'll be back whenever I need a question answered in a hurry. Stephanie P
  • Wonderful service, prompt, efficient, and accurate. Couldn't have asked for more. I cannot thank you enough for your help. Mary C.
  • This expert is wonderful. They truly know what they are talking about, and they actually care about you. They really helped put my nerves at ease. Thank you so much!!!! Alex
 
 
 

Meet The Experts:

 
 
 
  • Greg

    Greg

    Technician

    Satisfied Customers:

    1067
    Automotive diagnostic tech
< Previous | Next >
  • http://ww2.justanswer.com/uploads/IN/indytech/2013-8-8_102717_SantoDomingo146598x6402.64x64.jpg Greg's Avatar

    Greg

    Technician

    Satisfied Customers:

    1067
    Automotive diagnostic tech
  • http://ww2.justanswer.com/uploads/35/350matt/2012-6-7_182356_matsavatr.64x64.jpg Matt's Avatar

    Matt

    Mechanical Engineer

    Satisfied Customers:

    4197
    BEng hons Mech engineering, in auto industry 22 years
  • http://ww2.justanswer.com/uploads/TE/techmachine/0601821347169_717372168_8940977_39623330_o.64x64.jpg Ross's Avatar

    Ross

    Diagnostic and repair technician

    Satisfied Customers:

    452
    Licensed diagnostic and repair technician
  • http://ww2.justanswer.com/uploads/RO/RobMechanic/068.64x64.JPG Rob's Avatar

    Rob

    ASE Certified Technician

    Satisfied Customers:

    82
    30 years trade experience
  • http://ww2.justanswer.com/uploads/UK/ukiaibal/2012-11-9_205920_SAM0109.64x64.JPG uk_iaibal's Avatar

    uk_iaibal

    UK Car Mechanic

    Satisfied Customers:

    1
    Verified Car Mechanic.
  • http://ww2.justanswer.com/uploads/NA/nabilc/nabilc_avatar.64x64.jpg Billy's Avatar

    Billy

    Trainer/ Master Technician

    Satisfied Customers:

    38
    Trainer 8+ years, master tech. 10+ years, SAE member
  • http://ww2.justanswer.com/uploads/MI/mikeamechanic/2013-4-2_175558_photo.64x64.JPG Mike Kelly's Avatar

    Mike Kelly

    Auto Service Technician

    Satisfied Customers:

    1256
    17 years experience as an auto mechanic, foreign and domestic. 5 years running my own repair business.