Papez

Here's the diagram. The R5/J17 relay on the top. J362 is the ECU The "a" connection then continues to S4 fuse, which also powers injectors. Makes me think if someone connected it right to the 15 lead to bypass the immobiliser (not sure if it disconnects just the fuel pump relay or disables injector outputs, too on the 1.6)

Thanks for upload. Definitely gives an insight to my Issue :) The file can be opened in Excel. Here's what I put together after a quick look. Starting at timestamp 417.51. The first column is throttle valve angle, second is engine RPM, next is specified and actual boost. The actual boost value follows specified boost, except for engine speed under 2000RPM. Does it correlate with how the car feels?

If it helps, I found someone who logged their TSI here The OP also had some issues, but claimed that during the logging, the engine worked fine and values look OK.. so it should provide some data for reference.

I can't give you PNs, but there are several things different on the engine itself: Pistons (higher CR) Camshaft (different profile, different bearing size on majority of engines, which also means different timing chain sprockets) Head (7mm valve stems, conical springs, though this is not necessary So it may be easier to just get the entire donor engine. Regarding the knock sensor boss, I think that 136M actually has it in different place (closer to the gearbox, above reinforcement rib), unless there were some 136Bs from transfer period.

@Breezy_Pete Hello, I stumbled upon this topic. Have you been able to get some data from this? Looks it may be the culprit of my issues, some data would help greatly. How exactly did the car behave before the change and has the problem been resolved?

So the service had some time to take some measurements and was able to replicate the fail. Apparently the turbo only pushes around 1.3-1.5 bar absolute in 2000-3000RPM when specified pressure is around 1.8. full pressure is only reached beyond 3000RPM. Wastegate actuator position seems to correspond with driving voltage and changes in specified pressure, but I noticed that at some points, voltage goes above endpoint setting and the actual position goes negative. If I understood it correctly, 0 should be fully closed wastegate, right? Or is there some extra range on these engines and the wastegate never really shuts off? Also, what is normal voltage range with wastegate shut on these engines? On mine, the endpoint adaptation is at 3.8V, but when it goes negative, it goes up to 4.2V. I'm asking, because my turbo is the older type, with 2mm spacer fitted between the actuator and its mount. From what I could found on forums, this spacer changes endpoint voltage from ~4.2 to ~3.6V, so this could mean that something wore enough to make the spacer ineffective? But why didn't ECU adapt to this wear then?

Looks like charging is fine. After deleting the faults and driving until the issue reappeared, only the P155A error persisted. Could it be anything else besides the wastegate actuator and turbo itself?

Thanks, I'll check it

You reminded me - the battery died shortly after this happened for the first time. But it was still original from 2012, so I didn't think much of it. However, new battery didn't fix the issue.

Hi, hopefully you won't mind my question here - I don't have an Octavia, but its close relative from a Spanish brand. But mechanically, they are same. Anyway, I have a 77kW CBZB. It worked flawlessly for the year I own the car, but when this summer started, I noticed occasional loss of power. It only happens in hot weather (around 30 degrees and up) with AC on. In most cases, it happened when I wanted to accelerate after mild climbing at lower gear at ~2000RPM. It feels almost like a limp mode, but no check light and I can still somewhat accelerate to around 60mph. Observing fuel consumption, it drops from 11-12l full throttle on 5th gear to around 9l/100km, so between 20-30% of the engine power is lost. Diagnostics have shown code P155A and P0299. That would suggest turbo regulation, but that's usually accompanied with P334A/B/C error. Also, it's weird it only happens in hot weather with AC on. When I tried to replicate the issue, without AC, it didn't happen even in the recent heatwave. Anyone can point me in the right direction? I don't want to just start swapping parts without proper diagnosis of the issue. Also, what's the difference between P155A and P0299? Both point to under boost issues, but it seems they are triggered by different problems. If anyone explained me what are conditions for these issues, it would be very helpful. Thanks in advance!

No 21. 6U0121038 for non-ac 6U0121051F for AC Each is paired to a different pipe no 27, AC version wraps around the oil filter to clear the accessory holder. No 29 appears to be heater matrix output hose, that returns to the #27 pipe from the rear.

It's a dual filament bulb. If you rotate it by 180°, you just swap broken brake and tail light filaments. The problem is,that brake is 21W and light is 5W. It shouldn't be possible to swap it like that without significant effort.

I've seen this before on INA tensioner for my Cordoba. They grinded away all VW markings, because it was not sold as a genuine VW part, but INA-branded part.

What if you just plugeed the outlet to the booster and try if the issue persists? (not while driving, ofcourse!)

I didn't find any connection from brakes to ECU. The clutch is even weirder, it's entirely mechanical, there's no electronic sensor at all. Brake could be explained by some air leakage from the booster, but I have no idea how clutch could have any effect on the engine, besides small load change from the gearbox. Weird idle and misfires during rainy weather was caused by bad ignition module on my 1.3. but those were notorious for failures, I'm not sure if the 1.6 had similar issue.