MK5 Golf GTI

All Things Mk5 => How to Guides / Troubleshooting => Topic started by: Numero9 on November 29, 2022, 08:39:06 pm

Title: P0299 - boost pressure regulation
Post by: Numero9 on November 29, 2022, 08:39:06 pm
Having fixed a dodgy boost pipe and clearing some codes I've not got a P0299 code. I've changed the DV which was already a rev G but torn for another and it's boosting well. What I'm not sure of is if it is overboosting or it is mapped and the 18psi is normal.

I've pulled the dipstick out when running and the idle is very rough so does that rule out a pcv issue?

Next I think I'll check the vac lines and the N75 solenoid

Anything else people would advise to check?
Title: Re: P0299 - boost pressure regulation
Post by: GVK on November 29, 2022, 10:51:23 pm
When I had my Edition 30 (stage 1 mapped) I sometimes got that code when scanning (no EML) but on mine the freeze frame data showed it was doing 6000 rpm with no or little boost, thus triggering the P0299 which is boost less than specified.

I did post about about it on one of the Facebook groups with logs and got a reply from a foriegn guy who tunes them and he said from memory that it was a software issue and running close to the 2500mBar Map sensors limit.  Could never feel that lack of boost though.

I'll see if I can find the post and copy + paste here.  Some chat about it on my thread https://www.mk5golfgti.co.uk/forum/index.php/topic,129143.15.html
Title: Re: P0299 - boost pressure regulation
Post by: GVK on November 29, 2022, 11:19:00 pm
000665 - Boost Pressure Regulation
P0299 - 002 - Control Range Not Reached
Freeze Frame:
Fault Status: 01100010
Fault Priority: 2
Fault Frequency: 1
Reset counter: 255
Mileage: 125716 km
Time Indication: 0
Date: 2000.00.00
Time: 09:09:33

Freeze Frame:
RPM: 6744 /min <<<<hi rpm  :signLOL:
Load: 81.9 %
Speed: 127.0 km/h
Temperature: 69.0°C
Temperature: 32.0°C
Absolute Pres.: 1010.0 mbar  <<<<  :fighting2:
Voltage: 14.097 V
Title: Re: P0299 - boost pressure regulation
Post by: Numero9 on December 02, 2022, 01:54:25 pm
It could be that also. Error came on when I was high boost, no engine light though.

Driven it a little and checked the codes this morning & no codes.

Will post back if it comes back
Title: Re: P0299 - boost pressure regulation
Post by: pudding on December 03, 2022, 04:33:47 pm
18psi sounds mapped to me. GTIs run a peak of 1 bar and ED30s run 0.9 bar.

You can easily tell if you have VCDS by checking the Flash count in the ECU info. Factory = 0.  The counter goes up 1 every time it's reflashed.

It's how dealers were rejecting warranty claims back in the day as you cannot go back to 0 again......which saw a huge rise in tuning boxes as they are invisible to the ECU.

The only way to go back to 0 is with a brand new 'virgin' ECU from VW. 

Off topic I know, but just for general info  :smiley:
Title: Re: P0299 - boost pressure regulation
Post by: Numero9 on December 06, 2022, 08:22:20 pm
18psi sounds mapped to me. GTIs run a peak of 1 bar and ED30s run 0.9 bar.

You can easily tell if you have VCDS by checking the Flash count in the ECU info. Factory = 0.  The counter goes up 1 every time it's reflashed.

It's how dealers were rejecting warranty claims back in the day as you cannot go back to 0 again......which saw a huge rise in tuning boxes as they are invisible to the ECU.

The only way to go back to 0 is with a brand new 'virgin' ECU from VW. 

Off topic I know, but just for general info  :smiley:

Cheers pudding that is good to know. Where in VCDS does the flash count live?