Help...My 2000 1.8T won't start when its below 60 degrees out. It cranks and cranks but nothing. Starts and runs great when it's warm or in the garage. Replaced battery, engine coolant sensor and plugz. Starts after I open the hood and let the sun shine on the engine. Tried disconnecting the MAF but still no luck. Only code on he VAG is 18010 - Power Supply Terminal 30 Voltage Too Low.

It is definitely a temperature sensitive issue.

Any suggestions? Many thanks

 

Are the battery cables clean? Does the voltmeter read 14 when driving
with lights off? Have the charging system tested, could be the alternator.
Could a new battery have a bad cell?

 

Had same problem with old battery. Plenty of cranking power. Connections OK, have a 14 on the voltmeter. Jump start did nothing. Also replaced the fuel pump relay. This has me stumped.

 

18010 is probably related to disconnecting the ECU. Was there any code before you DC the ECU.

 

Check your air intake temp versus the actuall outside temperature.

 

18010 = P1602 engine control module ( ECM ) - supply voltage low from battery, possible causes are battery was disconnected, battery discharged, alternator not giving a charge to the battery, wiring open circuit, blown fuse

 

I did get some codes before replacing the battery and aftter disconnecting a few things, but they have not come back. Here they are:

16955 - P0571 Intermittent
17952 - P1544 Intermittent
17580 - P1172 Intermittent

 

I don't know if yours is the same problem, but my car had a very similar problem. I don't have a scanner so i don't know the codes, but it would crank alot but no firing. I replaced the fuel pump relay, ($70 from napa) and now it runs fine.

 

I just replaced the fuel pump relay, but no change. It is definitely something that is sensitive to outside air temp. Does anybody know if there is an air temp sensor in the intake system?

 

Try resetting the throttle body, as you had 2 throttle codes.