immobilizer questions

I

idk

Hello guys!
Recently i got a battery replacement on my 1997 1.0 16V micra and the car wont start. The engine check lamp is flashing and i noticed that the red light above the radio has stopped flashing( I suppose thats the nats immobilizer), also the two buttons next to it arent working (hazard lights and windshield warm). I checked all the fuses in the car and they are fine. What could have happened and is there a way to bypass the immobilizer or reprogram the key. The car doesnt have central lock and the key has a small red chip.
Thanks in advance!
 
idk said:
Hello guys!
Recently i got a battery replacement on my 1997 1.0 16V micra and the car wont start. The engine check lamp is flashing and i noticed that the red light above the radio has stopped flashing( I suppose thats the nats immobilizer), also the two buttons next to it arent working (hazard lights and windshield warm). I checked all the fuses in the car and they are fine. What could have happened and is there a way to bypass the immobilizer or reprogram the key. The car doesnt have central lock and the key has a small red chip.
Thanks in advance!
Click to expand...
Is the red led on constant when the ignition is on?,
Tried disconnecting the batter for a hour and putting back on?


Sent from my moto g(6) using Micra Sports Club mobile app
 
The LED above the radio isn't functional, it flashes all the time as a theft deterrent and goes out when the key is turned in the ignition so it can't be used to tell if you have an immobiliser problem or diagnose any issue.

The immobiliser is inside the ECU in this car, there is a light on the side of the ECU that flashes out codes, this same flashing is repeated with the check engine light once you enter diagnostics mode.

The colour of chip in your key determines what version of NATS you have in the car, they are passive chips (no battery in the key) which are energised and read by a collar in the ignition barrel.


If you have no lights at all within the car and the headlights/demister/etc don't work, nothing at all works then the highest possibility is the battery is connected wrong. Either the + and - are mixed up, sometimes new batteries have plastic caps to protect the terminal and these get left on when the battery is replaced. If no fuses have blown there could be a bad ground but this is unlikely as there are many grounds. The new battery could have sat on a shelf for too long and discharged completely, or it could be a bad battery from the factory? If you have a volt meter you could test the battery you should ideally see more than 11.9 volts although 12.3 to 12.6 is better.
 
MattInARedMicra said:
The LED above the radio isn't functional, it flashes all the time as a theft deterrent and goes out when the key is turned in the ignition so it can't be used to tell if you have an immobiliser problem or diagnose any issue.

The immobiliser is inside the ECU in this car, there is a light on the side of the ECU that flashes out codes, this same flashing is repeated with the check engine light once you enter diagnostics mode.

The colour of chip in your key determines what version of NATS you have in the car, they are passive chips (no battery in the key) which are energised and read by a collar in the ignition barrel.


If you have no lights at all within the car and the headlights/demister/etc don't work, nothing at all works then the highest possibility is the battery is connected wrong. Either the + and - are mixed up, sometimes new batteries have plastic caps to protect the terminal and these get left on when the battery is replaced. If no fuses have blown there could be a bad ground but this is unlikely as there are many grounds. The new battery could have sat on a shelf for too long and discharged completely, or it could be a bad battery from the factory? If you have a volt meter you could test the battery you should ideally see more than 11.9 volts although 12.3 to 12.6 is better.
Click to expand...



I have checked the battery with multimeter and its 12.6V. The headlights, blinkers and stuff is working in the car. Only the two buttons next to to the immobilizer light, that are hazard light and the windshield warm are not working. I have tried starting the car with both keys and the result is still the same. It feels like it starts for a split second then the engine turns off and the check engine light is blinking all the time.
 
idk said:
It feels like it starts for a split second then the engine turns off and the check engine light is blinking all the time.
Click to expand...
thats usually a nats problem, does it run for longer with a drop of fuel down the throttlebody ?
 
definitely sounds like NATS if it's cutting out, with fuel blockage issues it will usually idle if nothing else

The problem with the 2 buttons that are not working, those are above the ECU. It could possibly be that water has got in there. The water is a common issue it drops down through the holes in the firewall through the heater matrix - is any of the carpet or sound-insulation wet?

Do you know how to get codes through bridgeing pins?
 
MattInARedMicra said:
The LED above the radio isn't functional, it flashes all the time as a theft deterrent and goes out when the key is turned in the ignition so it can't be used to tell if you have an immobiliser problem or diagnose any issue.

The immobiliser is inside the ECU in this car, there is a light on the side of the ECU that flashes out codes, this same flashing is repeated with the check engine light once you enter diagnostics mode.
Click to expand...

The led is functional and does indicate Nats status. Its not switched with the ignition but with the nats status. Like detected a good chip or not.
 
.Maarten said:
The led is functional and does indicate Nats status. Its not switched with the ignition but with the nats status. Like detected a good chip or not.
Click to expand...
Yep
Flashes when the key isn't in to chow it's function
Goes out to tell it's off when the key in and everything is fine,

Then if it's on solid with the key in there's a issues from ECU, chip, key ect,

Easy way to tell is bit of petrol or easy start of somthing into the throttle body and see if it starts , if it does
Then it's a nats or fueling (had one that I had to manually suck the fuel to the fuel rail for it to work again)

If it doesn't start check the dizzy cap and rotor are ok, they do corrode and may want cleaning out

Sent from my moto g(6) using Micra Sports Club mobile app
 
Have a look in engine bay by battery front left when facing car you will see black box of relays and fuses sometimes there is a poor connection from cables going in to box ( could have been disturbed when changing battery)
 
Thank you all for the help guys i finally slove it. Looks like the antenna that reads the chip in the key has gone too weak. So i tried putting the spare key next to it and starting the car with the other key and it worked. The engine lamps stopped flashing and the car started.
 
Hi All,
I have a very similar problem with my daughter's car, 2000 1.0 3 dr auto.
Just stopped dead and has refused to start since. She only has 1 key.
Check engine light flashing constantly. Checked codes using paper clip method, OBD2 scanner doesn't fit. Codes found are 14-1 and 14-5, NATS related?
I don't know which version of NATS I have, key has a battery and remote locking buttons, which don't work, haven't done since she got the car 12 months ago.
NATS LED flashing normally when key removed and goes off when I try to start the car.

What I have done so far (found all these checks on here):

Disconnected battery overnight - no difference.
Disconnected ECU overnight - No Difference.
Checked all fuses and relays, all OK.
Checked distributor cap and rotor arm, quite worn but have cleaned/sanded them.
Strong smell of fuel when trying to start car, so I assume the fuel pump and injectors are OK.
Checked wiring to NATS antenna ring, nothing obviously wrong.

Its an old car, but she wants to try to keep it going, autos are rare here (Ireland), so don't mind buying an ECU kit from a breakers if necessary.

Any advice appreciated.

Thanks.
 
yes there are a few 141 143 etc nats threads
yours should be the later (pre 2000) 7 or 8 wire transponder ecu kit (without the extra nats box)
 
Last edited:
Thanks for the reply Frank.
I have been searching the forum, and the Aussie one, for a couple of days. I am 99% certain it's a NATS issue.
As I mentioned there's only one key, quite tatty and battered.
I am leaning towards a replacement ECU from a scrap yard.

Am I right in assuming that it has to be an ECU from an auto?

There is one on Ebay, ECU and chip only. If the chip is attached near the antenna and the PCB removed from my key, will this suffice, or should I be looking for a full set, ECU,
barrel,keys etc. Not bothered about central locking.

Thanks again,

Bob.
 
frank said:
i think you will need the ecu/transponder/chip kit from a 1st facelift bob
and most k11 auto,s have a separate g/box ecu
Click to expand...
Morning Frank,
Yes, mine has a separate g/box ecu. Do I need to change both?
There are various numbers o the ECU, do you know which ones are important?
Bosch no 0 261 204 245 matches mine.
 
just the engine one mate
there are at least 4 configs, the early prenats oblong ecu, the later square ecu with a nats box on the n/s pillar, then the square ecu with no nats box but more wires on the transponder, then the motronic coilpack ones
 

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