I have a Audi Q5 2.0 turbo . I got a cel for my boost pre...

Hello, my name is \*\*\*\*\* \*\*\*\*\* I will be helping you with your question today. I've been working on Audis for over 30 years now, so I should be able to help you through this. Please understand that some of my suggestions may require special diagnostic tools and equipment that many home mechanics may not have, but are often required. So, my first question is whether you're planning on performing your own repairs, or are you wanting to be armed with information before bringing it into your mechanic? **Also, the site automatically prompts for a phone call. It's very rare that I'm available by phone, so let's hold off on that for now. If needed after we exchange some information, I will do my best to take the time for the call.** Couple of other questions please: 1) can I get a VIN? 2) what scan tool are you using? VCDS or generic OBD2 scanner? 3) is the fault code a P0299? 4) have you already removed and checked the diverter valve? 5) how many miles are on it?

I'm using Carista OBD two scanner scannerP0236I remove the diverter valve the diaphragm on it looks good and it's also very cleanI have 101,000 miles on it

Super. Thanks for all of that detail! Now, let me chew through this a bit

It also came up with a VAG fault code 01466I do all my own repairs

Ok, got all of that also. Still working through a few things here

Ok

One other question, as we might get into wiring issues here, especially considering how much work you've done so far. Got a multimeter, and are comfy with DC voltage testing?

YepThe only thing I haven't done is check the wires from the sensor clip

Yep, that's what we're going to do here. I want to make sure my wiring diagram matches your car, so can you confirm wire colors to the sensor? Pin 1: brown/green Pin 3: grey/yellow Pin 4: yellow Is that correct?

One second

no prob

that's correct

Ok, that's good. With key to on position, can I get a DC voltage reading to the hundreth (xx.xx) on each pin please? Plug removed, not backprobing

Ok tell me if this is close because this is not my multimeter I may be off on settings

Yep, waiting

On the yellow I am getting 05.66

Ok good, that's a reference voltage

Do you one second I'm working on it

yeah, I'm on for a while, no time limit here

Ok good I'm I'm trying to do this with the phone.On the gray with yellow I'm getting zero

ok, that's not a bad thing.

OK on the gray is05.02The ground wire is jumping all over the place it went up to 300.5 and now it's down to05.30Brown wire sorry

That's odd, since it shouldn't go over 12v at all. It went to 300V?

Yellow 05.66Gray 05.03Brown05.30OK the multimeters were acting up I think that's rightSorry bout that

Odd that they're that close. No wiring damage, critter invasion, no signs of that?

Not that I see no

Ok, this one is getting a bit tough. The sensor you replaced. Right from the dealer? I'm going to look it up to double check the part number

It's was from oriellys . I was wondering about this because it was not an actual volkswagon sensorIt's beck arnleyPar number(###) ###-####

See, everything you've done so far looks good. I'd definitely suspect the sensor at this point. Audi part number 038 906 051 E

Would it be a big deal if it was not a actual Audi sensorIs the first Audi that I have had I know in a Honda that pretty much does not matter at all but I see on forums if you guys have gotten other two sensors and they were faulty until they actually got one from AldieAudi

Possibly yeah, since all of the inputs look good here.

I started to think that maybe the turbo hed went But a very low RPM I can hear the turbo spool and then it gets to about three grand and I can hear it dumping the air so I'm assuming that the turbo is good it was fine with no issues until this and this sensor is the only thing that keeps coming up. I clean the old sensor and put it in while in wide-open throttle I feel it start to boost and then stop start to boost and then stop until you hear all of the boost escaping the motor

Yeah, I've replaced a LOT of turbos in these, but you would always see a P0299 fault as well. Also, if you had a scan tool that could display actual vs ECU-commanded turbo boost, that would help, but that does require VCDS or other Audi specific scan tool

The only other one I have at my shop is a snap on oneWhich that might possibly give me a little more info than this Carista

Yeah, I'm really only familiar with VCDS on these, but any scan tool that has make-specific ability should be able to show these data points.

Ok so the sensor wires are giving accurate number tho so the wires should be ok ?

It's looking right. Unfortunately none of my service info shows exact readings needed, but with voltage readings to all, they look correct.

Ok I am scanning car now to see if it has a diff code

ok

I have live data on this scannerReading 0 on boost pressure Is there anything that I need to be looking for pretty much shows everything while the car is running

There should be 2 fields. Commanded or requested boost pressure and Actual boost pressure. I usually send two techs out, and monitors both of these on a graph while driving. But if it's showing zero while idling, I really think the sensor is suspect

I revved it up when I first started itHeard the turbo spool and heard the diverter valve dump.And now revving it up it sounds like a naturally aspirated motor very very little spool you can barely hear it

if the ECU is getting erroneous readings from the sensor, it won't allow the turbo to develop boost, and turn the diverter valve to just dump boost, or restrict wastegate closing

Yeah I know that much Is it that common for a non-Audi sensor to be faulty in these carsOr not work correctly you knowOK so while driving I can hear the turbo schooling very minimal so the turbo should be fine I hear the air dumping when I let off the throttle so the diverter valve should be fine so we pretty much think that it's the sensor and I need to get an Audi specific sensor

Yeah, let's start with that. I always hate condemning new parts, and don't want it to sound like a cop-out, but at this point, it's best.

I feel like that's the only thing it could be at this point because everything else seems to be working as it should I'll try that and I appreciate it buddy

No prob at all. Post back with results please

sir

Cool. Have a good evening

Question

yes?

Besides the breather hose do u know a different vacuum line to tap into that will work for a boost gauge . ?

oh, I responded to that already in your new session