P0234, P1441, P0245, P0216. Fixed with new ECU

[Brett San Diego]

2002 Jetta, wagon, manual. 431,000 miles.

For about 2 years, I've had an intermittent overboost fault and check engine light. Occasionally, the boost would drop out while driving. Some driving conditions seemed to promote the issue like being under load in 4th or 5th gear and at higher rpm. Boost would drop out, but only sometimes would I get a check engine light. The code was almost always P0234 (overboost). In recent months, I also had P0245 (N75 open circuit) popping up here and there. I swapped out the N75 valve for a new one, and that seemed to calm down the N75 fault for a bit, but it came back after a while. Cycling the ignition would always cure the issue and return normal operation during all this time. The check engine light would persist, and I would just turn it off with a simple OBDII code reader.

A couple weeks ago on a long drive, it crapped out much worse. More severe limp mode. The engine would rev only to 3,000 rpm, no power. Barely could get to 50 mph on a flat. And also more codes I hadn't seen including P1441 (EGR open circuit), P0216 (injection timing circuit control malfunction) along with P0234 and P0245. This afternoon, I finally got my Jetta transported back home, and I swapped in the immo-deleted ECU from my other ALH (2003 Jetta wagon manual swap), and the problem was instantly fixed. I just took it for a short test drive but replicated conditions where it usually dropped boost (4th or 5th gear, wide open throttle), and it ran solidly. So, I'm convinced it is completely fixed, and my ECU had started to fail more than 2 years ago.

Brett

 

[burpod]

I've read some ECU have had problems with some solder joints. It's likely fixable in the hands of someone with good board soldering skills

 

[Brett San Diego]

I've read some ECU have had problems with some solder joints. It's likely fixable in the hands of someone with good board soldering skills

Yeah, I wanted to ask if anyone knew of a good ECU repair service. All the open circuit codes certainly scream failed solder joints, as well as the 2 years worth of intermittent failures.

Brett

 

[burpod]

cluster by litke surely could do it, probalby a number of people on here could too. on my todo list is to practice soldering sockets onto 99.5 ecus but never seem to find the time....

 

[P2B]

I'm certainly comfortable reflowing SMT solder joints, used to repair and modify PC motherboards (hence the username), but I doubt you want to ship your ECU to Canada.

 

[Brett San Diego]

Update: Since this post, I have had a couple of overboost faults, so it seems the overboost persists, but it runs perfectly fine otherwise. All other issues are solved. My guess is the turbo vane mechanism just needs a cleaning. So, the ECU probably hasn't been failing for a couple of years, but maybe it started to fail 6 months or so ago when I got the first N75 open circuit fault.

Brett

 

[wonneber]

Update: Since this post, I have had a couple of overboost faults, so it seems the overboost persists, but it runs perfectly fine otherwise. All other issues are solved. My guess is the turbo vane mechanism just needs a cleaning. So, the ECU probably hasn't been failing for a couple of years, but maybe it started to fail 6 months or so ago when I got the first N75 open circuit fault.

Brett

I had that problem with my 2003 JSW while I was still working also.
I read to give the car an Italian tune up more often.
Every day on the way to and from work after the temp gauge was almost up to temp I would punch the peddle in 4th and keep the RPM's up for a bit.
Same thing on the way home.
Took a while but the problem went away.
I still do this with my 2014 JSW but still do this every time I drive the car.
Costs nothing to try it. My favorite price BTW.

 

[Brett San Diego]

I've been hesitant to go full throttle because that tended to overboost it, but I need to try it just to see if it's behaving better.

I watched the boost graph in VCDS, and it's always quite a bit over the called for boost when under acceleration. At cruise, it's usually spot on except for these random excursions to high boost above the called for boost. When this occurs in the graph, I don't feel anything in the seat of the pants or hear anything from the engine. Strange. I don't know if these random boost increases are real or an electronic glitch from sensors or what. Anyway, it's running good now for the most part.

Brett