Help?

Jdirks3352

New member
Joined
Jul 16, 2019
Location
Montana
TDI
MK4 ALH
Hello everyone. I have a weird issue with my ALH. So here the backstory.

I swapped my wife's originally 2.0 Golf over too a ALH from a Jetta. Don't recommend it anyway unless you enjoy tearing out the entire dash and swapping the entire wiring harness. Anyway we got it all back together and running great. During the process I noticed there was an excessive amount of oil in the intercooler as well as ton of carbon buildup from the EGR. I decided to swap the VNT-15 out for the 17 and deleted the EGR system. After getting all that installed I drove it home and everything seemed great. The next day we went to drive it and it immediately started making a ton more of the "Diesel Clatter" noise and had no power. I went in with VCDS and checked the injection timing and adjusted that slightly which lessened the clatter but not the power. I got a Stage one Malone tune to fix the EGR delete CEL and for the power gains and hoping that might help clear up the issue but no dice.

It's throwing these codes.
P1549 Boost Pressure Controle Valve (N75): Open Circuit / Short to Ground
P1144 Mass Air Flow Sensor Open/Short To Ground
P1252 Start Of Cold Start Injector Open/Short To Ground

Any idea where to start looking for the short and whether this would cause it to go into limp mode?
 

jmodge

Top Post Dawg
Joined
Jun 18, 2015
Location
Greenville, MI
TDI
2001 alh Jetta, RC2 w/.205's 5speed daily summer commuter and 2000 alh Jetta 5spd swap, 2" lift, hitch, stage 3 TDtuning w/.216's winter cruiser, 1996 Tacoma ALh
Have you unplugged your MAF to see if it changes anything?
 

Nuje

Top Post Dawg
Joined
Feb 11, 2005
Location
Island near Vancouver
TDI
2015 Sportwagen; Golf GLS 2002 (swap from 2L gas); 2016 A3 e-tron
Check the plastic pipe that leads from the vacuum pump to the brake booster. A small leak there can affect how much vacuum the N75 is able to get to move the turbo actuator.
 

wonneber

Top Post Dawg
Joined
Oct 12, 2011
Location
Monroe, NY, USA
TDI
2014 Jetta Sportwagon,2003 Jetta 261K Sold but not forgotten
It's throwing these codes.
P1549 Boost Pressure Controle Valve (N75): Open Circuit / Short to Ground
P1144 Mass Air Flow Sensor Open/Short To Ground
P1252 Start Of Cold Start Injector Open/Short To Ground
Check fuse 34 for power.

Check you have power to the N75 valve yellow / black wire.

Check the ground on the center of the firewall the maybe clean the grounds under the battery tray.
It the one under the battery is bad then everything that grounds to the body is bad.
 

Jdirks3352

New member
Joined
Jul 16, 2019
Location
Montana
TDI
MK4 ALH
We'll gosh darn it, it was fuse 34.I went through them all with a tester but didn't actually pull them. Sure enough it was blown. New fuse cleared all the CEL's and after adjusting the injection timing it runs great. Thanks everyone!
 

wonneber

Top Post Dawg
Joined
Oct 12, 2011
Location
Monroe, NY, USA
TDI
2014 Jetta Sportwagon,2003 Jetta 261K Sold but not forgotten
Gota catch a break one in a while. :)
Glad you posted the fix for others down the road.
 
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