Weird throttle and multiple codes after water pump replaced?

[Curare]

Hi All, first time poster here, I've been a Subaru guy for the last 30 years but needed a change and decided a B8 wagon would make a nice change from my Legacies.

I recently had a coolant leak and set about changing the water pump. I chose (what I thought was the smart way) to leave the intake manifold ON and remove only the throttle body to gain access to the pump.

I'd put everything back together made sure all the plugs were plugged and fired it up and it's thrown multiple codes (ACC/ESP/Tyre Pressure) and a CEL. It's also taking a long time to start and the throttle response is all over the place.

The majority of the faults seem to be a U112300.

It's no secret in VAG land that multiple codes can be diagnosed to an ABS sensor. I checked my live data and all four corners are showing speed but the front two sensors have an error for direction and air gap. I can't see how BOTH sensors would have failed from the car being parked up while I did the pump. I've gone as far as removing them and giving them a clean, but there's no damage to the cables, everything looks kosher.

Can anyone give me some guidance on where to look next? I've cleared the codes multiple times and the same thing happens.

Also, how do I add my history? I seem to go over the character limit if I try?

[Curare]

Addenda, I post this on the OBDeleven forum too, so far no-ones got anything to say:

History is posted there for reference.

Just a moment...

[MIG]

Have you done the steering wheel to each side endstop for 3 seconds? Steering calibration will cause errors each time the battery is disconnected.

[Curare]

Yep, just went and did it, nothing changed..

I assume you just go lock-wait 3 secs-other lock-wait 3 secs-centre?

[MIG]

Yep the procedure is outlined here How To Replace and ADAPT a VW or Audi Battery - YouTube

U112300 - Databus error value

Any wiring was disconnected or moved around while you did the work?

Edit, you also have U101100 - Supply voltage Voltage too low

Intermittent on a few modules, how is the battery voltage?

[MIG]

Also, focus on static codes, not intermittent as they could have been caused when things were unplugged.

The concerning one is the one below; this would have caused your longer-than-normal start and throttle response issues, as the ECU needs to calculate the crankshaft position based on the camshaft position sensor(and needs a full rotation to do so), thus it's running in "limp" mode.

P033500 - Crankshaft Position Sensor A Circuit
static

Recheck the cables; I think the 1.8L has the same layout as the 2.0 (someone else, please confirm). I am not up to date on the 4cyl engines. See here for locations Injection system engines 2,0 EA888 - Overview of fitting locations labelled sensor G40

[Curare]

Also, focus on static codes, not intermittent as they could have been caused when things were unplugged.

The concerning one is the one below; this would have caused your longer-than-normal start and throttle response issues, as the ECU needs to calculate the crankshaft position based on the camshaft position sensor(and needs a full rotation to do so), thus it's running in "limp" mode.

P033500 - Crankshaft Position Sensor A Circuit
static

Recheck the cables; I think the 1.8L has the same layout as the 2.0 (someone else, please confirm). I am not up to date on the 4cyl engines. See here for locations Injection system engines 2,0 EA888 - Overview of fitting locations labelled sensor G40

AHA! Thats the information I needed! I went for a rummage around where the dog belt connects to the secondary shaft as I know I might have disturbed that sensor when I felt something dangling off the wiring harness....

Sure enough the crank sensor pigtail was not plugged in, so a bit of gymnastics to get the plug on and voila, the car was immediately happier! I think that was the missing peice of the puzzle!

It's weird as I don't recall unplugging that sensor but I can't say for certain whether I did or didn't. Either way the evidence tells the story.

Thanks for the point in the right direction!