Urgent help needed. 172 cup won't start :(

[Dave Hester]

So, got in my 172 cup last night, put the key in the ignition to start the car as normal, turned over for 3 seconds and then just stopped, I then notice the immobiliser light is still lit red and solid. Great.

Done a search on here and tried everything suggested but still the red immobiliser light wont go out.

So far i have
: checked all fuses
: recharged the battery
: put a new battery in the keyfob
: checked the earth to the battery
: done every ignition on/off , locking doors on/off trick

I have read on here that it could be a faulty decoder ring but usually this is needed with a constant flashing red immobiliser light, not a solid one.

Where should i go from here and what else can i try??

Any help but be so appreciated

James

 

[montana]

long shot but have you checked the voltage reading from the battery when fully charged?

 

[Budgie]

Disconnect the battery for 20 minutes or half hour and try again.

 

[.Adam.]

Try removing the bucket from the engine bay?

 

[Dave Hester]

Disconnected the battery last night and put it on charge through out the night.Connected the battery back up this morning and still the immobiliser light wont go out

 

[edde]

Try your other key if that doens't work get a new imobilier ring.

 

[Dave Hester]

Can i try any decoder ring from an other 172 or does the ecu, uch, decoder ring and keys all have to match??

 

[Greeny.]

Try removing the bucket from the engine bay?

ROFL

 

[lemonnobby]

no decoder rings are a straight fit. but i bet its a key and the battery is deffo ok

 

[jimmy3285]

just sorted the exact same problem with mine. Was one of two wires running from uch to ecu. Im just about to go out for the night so will be back on tomorrow to give you details if you like.

 

[jimmy3285]

on mine the two wires are 57 on the ecu to 19 on the uch and 27 on the ecu to 20 on the uch. One should be white the other should be violet. check the continuity with a multimeter. i had a break in one so i just spliced on and ran a fresh wire throw easier than trying to find the break. If your unpluging the ecu and uch and things make sure you disconnect the battery first.

 

[Dave Hester]

Thanks Jimmy, mines a different engine to yours but i can imagine they all have a similar set up

just found this on mine, looks like the ecu case has been rubbing through the armoured sleeve in the ecu wiring!! or not till I have a proper look

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[jimmy3285]

yeah that seems a very common fault. someone had been nice enough to f**k that casing off mine before i bought the car. good luck sorting it out. i now know what a pain finding that fault is

 

[Dave Hester]

Auto electrian has ben today and had a good look at the wiring in the engine bay, still not find anything!

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