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.
  • Go back-and-forth until satisfied
    Rate the answer you receive.
Ask sebastian manrique Your Own Question
sebastian manrique
sebastian manrique, Auto Mechanic
Category: Car
Satisfied Customers: 1672
Experience:  Director Ejecutivo at Multiservicios Cruz de las Mercedes
Type Your Car Question Here...
sebastian manrique is online now

Changed battery on a smax now we have immobiliser active and

This answer was rated:

Changed battery on a smax now we have immobiliser active and cannot start
Assistant: Have you changed a battery before?
Customer: No
Assistant: What is the model/year of your Ford?
Customer: 2010
Assistant: Are you fixing your vehicle yourself? What have you tried so far?
Customer: At garage. New battery installed
Assistant: Anything else you want the Mechanic to know before I connect you?
Customer: No

Hi, my name is Jose Sebastian, your mechanic automotive expert, and I will be happy to assist you today. In some cases, I may need more information to assist better. I apologize for any delay.

I try to be here most weekdays and some weekends. If you respond and I do not respond back right away I will do so as soon as I can.

Dear customer, I understand your query. I want to explain you, you have a deconfiguration in the system of recognition of the key and immobilizer, let me explain how your immobilizer system work

The electronic immobilizer protects your vehicle by means of an electronic code integrated in the key. This is composed of an invariable personal code and a second code that the immobilizer modifies each time the engine is started.

When starting the vehicle, the immobilizer checks the personal code and the variable. If both codes are correct, the immobilizer sends a new coded signal to the engine control to unlock the engine. Without this signal, the engine can not be started, even by a short circuit.

If you have a problem in the key or in the immobilizer, your vehicle does not turn on, this happens a lot when we perform works in the vehicle, it may have unintentionally done a bad work done in the battery that made the vehicle think that you were trying to turned on without its respective key.
In your case, the immobilizer can not verify the codes, this type of problems is quite common when the replace of the battery is done, so you do not necessarily have to go to the dealership to solve it, although it would be the most prudent and correct thing to do, There are locksmith companies that can help you with your case, reprogramming the key fob, key and the immobilizer with a key programmer, and verify if any of the modules present damages or if there is a short.

This problem may be the most likely but there are another factors like a problem with the battery or fuses as well.

Have you understood dear customer?

Customer: replied 10 days ago.
Next symptom is this, the internal lighting does not work. All passenger electric windows DO work, and the red led is illuminated on each up down button. The drivers electric window does not work, the console (in the door handle) is not illuminated.
Customer: replied 10 days ago.
Then we have “stop lamps bulb fault” despite this being fixed (new bulb) two weeks ago.
Customer: replied 10 days ago.
I will take it to an electrical specialist. I think the immobiliser problem is a red herring.
Customer: replied 10 days ago.
When we were driving earlier today, the fan heater suddenly turned off and the dash board also turned off. We could not indicate left right The battery light came on, so alternator maybe? But we are unable to test the alternator since we cannot turn on the car.

Thanks for your reply and i apology for my delay.
This problem looks like a programming problem not just in the immobilizer but in the whole system.

This problem is common to happen and it may be due several causes i will try to cover the main ones in order to make you and idea of what you have to check to rule them out.
1) ECU deprogrammed. When the ECU gets deprogrammed may cause problems like yours and indicators could start on in unexpected ways or symple stop working. This can be solve with a Ford diagnostic scanner tool. Scanning, deleting the error codes, the scan would show and reprogramming will sorted out the problem. It isthe most common way to sort out the problem.
2) Wiring loom problems. If the wires or the wiring loom is split, broken, melted or burned can cause problem like the one your are passing through. Also the connectors can be corroed or loosen and it can cause problem like yours.
3) Damage in the dashboard module, when the module is defective does not send any signal or send erroneous signal to the dashboard and it cannot work as usual.
4) Problems with the ECU, when the ECU is defective can cause different problems an one of the main problems it cause is problems in the dashboard. If after reprogram, check the wires, plugs and the module the problem is not solved. The problem will be in the ECU.
The ECU could be the most expensive repairment but hopefully your problem will be easily solved reprogramming, as you have several indicators lit, without mechanical faults and it happens unexpectly.
Dear customer, you could also try the manual reset to see if your car gets back to work as usual:
1) Turn the key to ON position without ignite the engine.
2) Disconnect the negative terminal of the battery.
3) Wait around 3 to 5 minutes to let all the modules delete its data.
4) Turn off the key and take it off.
5) Reconnect the negative terminal.
6) Turn again the key to ON position and wait around 30 seconds to let the modules restart.
7) Turn ON the car

If after doing the manual reset the indicator are still on, you will need to go to an independent garage or the dealer to perform the reprogramming with the diagnostic tool with the ford software as i told you before.

Have you understood me dear customer?

My goal is to give you the best experience possible! I hope I have earned a 5 star rating today. Please remember to rate my service by selecting the 5 stars at the top of the screen before you leave JA today. If you need more assistance, please use the reply box below and let me know. It has been my pleasure to assist you!


sebastian manrique and 3 other Car Specialists are ready to help you