Need Help ECU problem

[noone]

Simple check, remove your head unit, check cabling.

[vwthunder]

Took the headunit out. Didn't make a difference. Doh

[pologti18t]

Could it be a failing battery??

[Jmac]

Took the headunit out. Didn't make a difference. Doh

Can check with VCDS mate, block 125

[vwthunder]

Did a scan thanks to johnw, thanks for the use of the cable

[Hilal]

Get your battery tested. I had this same problem happen to me when I first bought my car, battery was dead, nothing would work but the engine still started. After I replaced the battery, got all the codes cleared, and it was all good.

Regarding your engine codes, thats something else.

[Stuwey]

You put a smaller battery in... And you've got a big stereo.... And you're having electrical faults...

2+2=4.

More electricity required. Thats why they have such big batteries standard.

[noone]

Once the car is running it's the alternator that supplies power. Big stereo setups often have bigger alt's

[vwthunder]

I am running 2 amps one for sub and another for front speakers, car seems to start better with new battery.
It is not that small it is 450CCA which should be pretty good, I think standard is 500CCA or 550

Stereo works and lights on etc when car is turned off, so i didnt think the battery was lacking power

[Stuwey]

Yeah, but how many volts do you have???

You'll need at LEAST 14.4 to keep these little tech-boxes running. Faulty battery or faulty connections are where i'd be looking.

You have an electrical problem, which occured after you changed your battery system.


Return it to standard and go from there...