2008 Mazda 2 - Immobiliser issue?

[becky221093]

Hi there my 2008 Mazda 2 currently will not start. I am new to this forum so any help would be greatly appreciated.

when i turn the key to start the engine the immobiliser light flashes and the engine does not start. you can hear the fuel pump kick in but thats it.

I have tried plugging a generic OBD2 machine in and it comes up with no fault codes. Hoping and praying that is not going to be an expensive fix and willing to try anything!

Thank you in advance!!

Becky

[triple5]

Has the key battery been replaced recently?

Not exactly your symptoms but my daughter had the immobiliser light come and a new battery fixed it, car was still starting ok though.

[triple5]

Has the key battery been replaced recently?

Not exactly your symptoms but my daughter had the immobiliser light come and a new battery fixed it, car was still starting ok though.

[becky221093]

triple5 said:

Has the key battery been replaced recently?

Not exactly your symptoms but my daughter had the immobiliser light come and a new battery fixed it, car was still starting ok though.

Not sure its an issue with the key as locking works fine..

[triple5]

becky221093 said:

Not sure its an issue with the key as locking works fine..

Locking worked fine on ours as well.

[becky221093]

Update had auto electronics guy out today who confirmed no issue with key

[triple5]

Something here which talks about resetting the immobiliser.

Did the auto electrician know what the problem was? have you tried both keys?

[becky221093]

Hi thanks for replying no the electrician didn't know! just tried the thing with battery no luck also checked all the fuses and they're all fine too any other suggestions?

[feef]

I believe the immobiliser disables the fuel pump, so if you can hear it energising then it may not be an immobiliser problem.

[becky221093]

Okay update here - auto electrician came out today and confirmed no issue with key.

-checked all fuses all fine..
-checked battery and it fluctuates when its connected but when i disconnected it then it stopped fluctuating and stayed at a constant 12.5?! any ideas? could this be related to y issue?


Thanks!

[feef]

becky221093 said:

Okay update here - auto electrician came out today and confirmed no issue with key.

-checked all fuses all fine..
-checked battery and it fluctuates when its connected but when i disconnected it then it stopped fluctuating and stayed at a constant 12.5?! any ideas? could this be related to y issue?


Thanks!

Connected with the ignition on, ignition on and engine running, or with ignition off?

[becky221093]

connected with the ignition on makes it fluctuates loads! Cannot try with engine on as it won't start

[feef]

becky221093 said:

connected with the ignition on makes it fluctuates loads! Cannot try with engine on as it won't start

yeah, sorry.... Engine on is a pointless query in hindsight

Which position does it start fluctuating? Does it happen with the key in position 1 (accessories) or position 2 (ign 1 and ign 2 circuits enabled), or both?

[becky221093]

feef said:

yeah, sorry.... Engine on is a pointless query in hindsight

Which position does it start fluctuating? Does it happen with the key in position 1 (accessories) or position 2 (ign 1 and ign 2 circuits enabled), or both?

Thats a very good point, i didn't know to check both so only checked at position 2! it was fluctuating very fast from 1-4 ish

[feef]

becky221093 said:

feef said:

yeah, sorry.... Engine on is a pointless query in hindsight

Which position does it start fluctuating? Does it happen with the key in position 1 (accessories) or position 2 (ign 1 and ign 2 circuits enabled), or both?

Thats a very good point, i didn't know to check both so only checked at position 2! it was fluctuating very fast from 1-4 ish

Any clicking noises while it fluctuates?

[becky221093]

Nope not that i could hear the only noise was the immobiliser alarm...

Just seems weird that it would fluctuate, excuse my technical knowledge! i put the multimeter on my other car while it was in position 2 just to make sure i was doing it right and that stayed constant!

Thanks again

[feef]

Stupid question time, but has the car battery been replaced recently? It COULD be on the way out, or have a bad cell. That could show up as 12v when there's no load on it, but do some odd things when the ignition is on, especially if it can't give enough oomph to maintain a component in operative state, so could be flicking on/off and so affecting the voltage at the same time

[becky221093]

feef said:

Stupid question time, but has the car battery been replaced recently? It COULD be on the way out, or have a bad cell. That could show up as 12v when there's no load on it, but do some odd things when the ignition is on, especially if it can't give enough oomph to maintain a component in operative state, so could be flicking on/off and so affecting the voltage at the same time

Nope not been replaced in a while but i have a spare somewhere i will put in on charge and try that tomorrow! Could this battery issue be affecting the immobiliser or would this be a separate issue?

Thanks for all your replies feef!

[feef]

becky221093 said:

feef said:

Stupid question time, but has the car battery been replaced recently? It COULD be on the way out, or have a bad cell. That could show up as 12v when there's no load on it, but do some odd things when the ignition is on, especially if it can't give enough oomph to maintain a component in operative state, so could be flicking on/off and so affecting the voltage at the same time

Nope not been replaced in a while but i have a spare somewhere i will put in on charge and try that tomorrow! Could this battery issue be affecting the immobiliser or would this be a separate issue?

Thanks for all your replies feef!

It 'could' affect the immobiliser if there's something somewhere that's not getting enough power to do it's job, whether that job is to disable the immobiliser or perhaps draining enough power that it causes the immobiliser to fail.

It's an odd one, to be fair, so best bet is to start with the obvious things and work from there.

Where are you based?

[becky221093]

Ok well I'm praying for a simple fix!!! Im based in macclesfield, Cheshire.