Immobiliser - Car wont start - Help (Not Daily)

[Ross15]

Hi All,

Been a while since been on here but finally getting the car back on the road after a longer period than expected side-lined.
The car has been off road for 2+ years, separate trouble shooting post to follow on getting it running again after it failed to hold an idle then never started again after I burned out the starter motor.
Its 63k, 2008 231 version with AEM CAI and Blitz catback. I’ve owned it since 2010 with no real issues other than some dodgy “brainstorm tuning” coils, having to decat, oil hose leak and a blown fuse about 9 years ago.

Immobiliser Problem:
To get to the next stage of troubleshooting ive done some repairs (listed below with battery out). I put the battery in on Saturday which was flat but enough to get the alarm going.
No problem, so on Sunday I hooked up my daily and charged the battery via booster cables for 15mins then connected the RX8 battery (with booster cables disconnected, then re-connected). All good.
Turned the key to on position…nothing…..immobiliser light blinking continuously.

Attempts to fix:
It’s the original switchblade key so replaced battery – still nothing
Try my 2nd switchblade (only had the key half though as it broke & still looking for the other half) – still nothing
Try the valet key – still nothing
The keys unlock the car manually and with the fob on the one key
Ive disconnected the battery and retried with all keys – nothing.
I tried the key reprogramming function but car didn’t acknowledge.
Plugged in my elm wifi OBD but cant connect as unable to find protocol (worked on my daily straight after). Tried my neighbours which has a display but this didn’t read the car either.
Tried the resets – Only the NVRAM (hold odometer) worked. The KAM with the brake pedal didn’t do anything although suspect the immobilizer doesnt allow access to reset.
Re-checked some fuses – cant see anything at fault – will recheck again tonight with multi-meter. What fuse would it be for this?

Fixes….The help part:
The car acknowledged the key fob to open and lock the doors. I don’t think anything has ‘lost its memory’ if it can still recognise the key to do this?
Ive searched and cant find much information if there is a hard reset or similar.
Anything else I can try?

I believe the alarm is part of the ECU.
I could replace ECU, or is there someone I could send this to for re-programming etc if this is a valid solution? Take it to local tuning shop perhaps they could plug it in and analyse?
An auto-electrician/key cutting person to come out and possibly try to reprogram the immobiliser i.e. wipe it clean and re-add the keys? Or something similar?

Repairs are nothing that should have interfered with ECU/Immobiliser as battery was removed. Due to it not idling I assumed either air or fuel issue as recently had new plugs/coils/leads/battery/starter motor prior to this. Nothing found wrong with the air side so decided to replace fuel pump as was due anyway, then take the troubleshooting from there.
Since its had new plugs/fuel pump/mounts filled and a few coats of wax, nothing that should have affected immobiliser.

Appreciate the help
Ross

[PeteH]

Just sounds like a dead battery to me! Connecting a drained battery to jump leads for 15 minutes will do nothing. Charging a dead battery takes between 10 and 15 hours. The RX-8 needs a good battery at the best of times, and waking your car from a 2 year slumber really requires a brand new battery, fully charged, and probably also connected to jump leads!

I laid my car up for about 4 years. When I came to start it I tow started it. It's way easier. I then put a brand new battery in.

The reason your car didn't hold idle was almost certainly because it had lost it's fuel trims. This is nothing to worry about. Try to leave the car idling for 10 to 20 minutes, and use the bare minimum of throttle just to keep it going. You engine will then relearn its trims. I just drove my car, and it learned its trims quickly enough.

I doubt your car has an immobiliser issue. Pop a new battery on, try tow starting it, and my guess is all will be dandy.

Best of luck.

[Ross15]

Hi Pete,

Cheers for the reply. The battery had been connected up to an RAC charger on and off for the past year. It was reading charged on the charger but then didnt have much juice when put in on Saturday hence the alarm. Was put back on charge then tried again Sunday with a direct charge off the daily and then connected to leads.
I agree its in need of replacing as not good for battery health to fully drain, got a new Varta E23 on order today so hopefully this helps.

[BigPete]

Check the fuses under the bonnet 3 impartial: IG Key, Engine and Egi inj there all 15A

If there all good then I have plenty of ecu and locksets for sale

[nightfire10]

Turned the key to on position…nothing…..immobiliser light blinking continuously.
Also check wiring to coils not shorting out which will cause this as iv'e found out lol

[casey]

I had the same symptoms a while back too. As nightfire10 stated, this was due to a short in the coil wiring to the engine lifting hook, which a few people have suffered with D585 installations and poor wire routing. Cause; wire insulation chafing after a few 1000 miles.

If this is the case, the give away sign will be a blown 15A engine fuse.

[Ross15]

Cheers lads will re-check tonight if im home in time. ill search some more info on the coil wiring and fuse blowing.

Bigpete, already got you on the sidelines for a replacement