Volkswagen Golf V - GOLF V 1.9 TDI hot start - how to remap?

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Mon 12 Nov 2012 14:51
Volkswagen Golf V - GOLF V 1.9 TDI hot start - how to remap? - asdf

I know this has probably been discussed a million times and I have googled extensively but I can't find much concrete detail.

My Golf shows the usual behaviour of starting super-easily when cold and having to crank for a while when hot. I understand that some people have fixed this with either 1) new battery 2) new starter motor 3) new both of these

BUT... I also gather that it can be solved by changing the engine management software to inject fuel sooner during a hot start. Please could somebody explain the following:

Does the ECU chip have to be replaced (like a re-map) or can it be simply edited? I don't really have any interest in getting a performance upgrade etc, I would just like to iron out this bug and be kinder on the battery/starter....

If this is all correct then I would be really grateful for a recommendation for where I can get this done nr South/West London and how much it is likely to cost?

Please assume I know nothing about ECU fiddling!!

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Mon 12 Nov 2012 14:58
Volkswagen Golf V - GOLF V 1.9 TDI hot start - how to remap? - thunderbird

The engine map will be exactly like it was when it left the factory unless someone has already tampered with it. Take the car to a VW dealer and get them to flash the ECU with the latest map for the car, if that does not work I would look elsewhere for a cure, a re-map will not cure it.

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Mon 12 Nov 2012 17:19
Volkswagen Golf V - GOLF V 1.9 TDI hot start - how to remap? - Crasher

One other method is to establish if the car starts faster with the coolant temperature sensor unplugged (you need to clear the fault code after doing this) and then install a 5 pin relay that disconnects the coolant temperature sensor when the starter motor solenoid is operating and drops the ECU feed onto a resistor that mimic’s the reading given when the engine is cold. As soon as the starter motor stops cranking the temp sender reconnects and the very short time the relay spends between contacts does not seem to generate an open circuit fault code.

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