Vauxhall Astra strange key starting problem with main and spare key

Car: Vauxhall Astra
Variant: 1.6 Energy Petrol
Model Year: 2007
Categories: Running Rough, Starting & Power Loss
Astra 1.6 energy petrol 2007

Over the last couple of weeks while it has been cold my Astra won't start. It turns over but won't fire up. All normal things checked at garage (battery etc.) but all okay. Car will start after about ten minutes of trying. It doesn't struggle to turn over it just won't fire up.

There is an error code 1600 that the garage says means the ECU (or EMU) needs changing at a cost of £800.

Someone mentioned trying the spare key.

A couple of mornings now I have tried the main key twice and it won't start. On the third attempt I tried the spare key instead and it starts first time using that key.

During the day the main key works fine starting the car first time. It just seems to be the first try in the morning when it either takes ten minutes of trying to start with the main key or so far seems to start first time with the spare key.

Any one got any ideas? I really don't want to splash out £800 !! If it was a problem with the key why does it only happen in the cold? The key is kept indoors so that isn't cold. If something on the car is cold then why does it start okay with the spare key?

Thank you.
Posted: Dec 6, 2014 (9 years ago)
Check the wiring to the ECU .There are numerous companies who will check and repair your ECU if needed .Also could load test /check battery as this TSB explains ,

Technical update 21/11/2014:

If you have all or most of the following fault codes stored, then the battery voltage should be checked during cranking, if the battery voltage drops below 8 volts then the Battery and starter motor should be checked/replaced. Also the body control module (on left side of engine compartment) should be removed from its connection cradle and check for connection problems underneath. Only after this has been checked should the engine ECU be considered as a possible cause of these fault codes.

P0201- Injector circuit 1
P0202- Injector circuit 2
P0203- Injector circuit 3
P0204- Injector circuit 4
P1600- Replace electronic control module
U2103- CAN BUS circuit malfunction no communication with can bus
U2104- CAN BUS reset counter overrun
U2108- Anti lock brake system no communication with CAN BUS
U2139- CAN BUS no communication with steering column module
Posted Dec 8, 2014 (9 years ago)
After a number of times at the garage and no luck they found a software update for the car. This was applied at a cost of £135 and appears to have completely fixed the problem.

The car now starts first time in the conditions it used to struggle to start.

Expensive but better than £800
Posted Jan 20, 2015 (9 years ago)

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