Engine light on a few weeks ago, and error code indicated bank 1 pressure switch. I swapped both pressure switches, and then reset the adaptation in VCDS and forced a dpf regen which all worked fine and completed ok. Now there is error p2452 indicating a further error in the pressure switch circuits. Can anyone point me to an electrical schematic, or give any clue where this problem might be?

 

110kw, CUUB, 2016

 

Thanks!

Welcome,

 

 

Did you have the saved log file you can share here?

 

If you have access to VCDS, what are you reading for pressure values with engine off/on?

So do they seem plausable values is what I mean.

Thanks. Sorry, I used a mate who has the vcds kit. Am considering spending £225 with Rosstech to get my own again…..my version was can-bus for the old Galaxy I had.

 

I replaced both pressure switches so am thinking circuit error…..unlucky if its another duff switch?

 

If i can get the right schematics I’ll ring it through to check.

….and odd that the forced regen worked just fine……?

I am going to prepare a few pages for you to look upon.

Thanks! Your help much appeciated……

17 minutes ago, Johnricketts said:

Thanks. Sorry, I used a mate who has the vcds kit. Am considering spending £225 with Rosstech to get my own again…..my version was can-bus for the old Galaxy I had.

 

I replaced both pressure switches so am thinking circuit error…..unlucky if its another duff switch?

 

If i can get the right schematics I’ll ring it through to check.

….and odd that the forced regen worked just fine……?

They do come up for sale upon here from time to time, just the other day someone mentioned they are moving away from VAG brand, and will have one for sale.
Recommend you get HEX-NET V2 or whatever they call the new one that can talk to the UDS modules.

 

More than likely you may find you may have replaced both sensors for nought, always take any error codes with a pinch of salt.

Thanks. Have just forked out £225 for the 3 VIN Ross-Tech cable now so should be able to plug it up on friday. 

 

Was a history of flaky switches around 2016 I believe….so I just swapped them both for abot £20 each

Did you do the VCDS procedures to adapt and relearn the new differential pressure values before starting the car?

 

42 minutes ago, b1ackb1rd said:

Did you do the VCDS procedures to adapt and relearn the new differential pressure values before starting the car?

 

I did, but will check again when I get VCDS going again on friday as I may have done it wrong…….

1 hour ago, Johnricketts said:

I did, but will check again when I get VCDS going again on friday as I may have done it wrong…….

 

There is an opinion 'out there' pn some forums that the adaptation procedure is a once only operation, and that if not done correctly a new module is needed - I'm not convinced myself, I can't see why the 'relearn' option won't work.

 

I understand from a friend who is a VAG tech that once the procedures are done you must leave the car for 20 seconds or so then remove the key and come back in a few minutes. 

@Johnricketts Don't forget you have an unread Private Message, top right on your screen.

9 hours ago, varooom said:

@Johnricketts Don't forget you have an unread Private Message, top right on your screen.

Thanks for the pm. Really useful if I have to ring it out after I check through VCDS again tomorrow!

I now have my own pucker VCDS running, and it was obvious the replacement diff pressure sensor was duff. I put another one in and it now seems to give plausible readings. However, I cannot seem to do the G450 adaptation because the ‘Coding II-11’ button is greyed out?

 

Any ideas?

(PS engine light is out for now but there is an offset on the switch with engine off (about 1000mV)

9 minutes ago, Johnricketts said:

I now have my own pucker VCDS running, and it was obvious the replacement diff pressure sensor was duff. I put another one in and it now seems to give plausible readings. However, I cannot seem to do the G450 adaptation because the ‘Coding II-11’ button is greyed out?

 

Any ideas?

(PS engine light is out for now but there is an offset on the switch with engine off (about 1000mV)

Pukka (you'll have Jamie Oliver spinning in his grave) 😁
 

 

I don't think you are coding this change!

 

UDS Protocol (G450) procedure

Key ON, Engine OFF
[Basic Settings]
Select Adaptation of diff. pressure sensor particulate filter
[Go!] to activate the Basic Setting.
After the result of Finished Correctly appears click [Stop]

Select Resetting of learned values of difference pressure sensor
[Go!] to activate the Basic Setting.
After the result of Finished Correctly appears click [Stop]
[Done, Go Back]

 

 

 

CAN Protocol (G450) procedure

Instructions should be populated in a pop-up balloon when connected to the controller in question with VCDS.

Key ON, Engine OFF
[Coding-2] or [Login-II] button
Enter the code shown in the VCDS pop-up balloon
[Do It!]
Switch Ignition OFF for 30 seconds

After the key is cycled back on the adaptation should be completed. If it is not completed, proceed with the next steps:

These steps must be repeated 5 times.

• Ignition ON
• Wait 5 seconds
• Ignition OFF
• Wait 40 seconds
• Repeat 4 more times

Yes, but the ‘Coding -11’ button is greyed out!

22 minutes ago, Johnricketts said:

Yes, but the ‘Coding -11’ button is greyed out!

Was you following the UDS instructions, and can you see it under Adaptions?

I will go look at my car, I am sure it's there.

 

Mine is UDS and I couldn't see anything to adapt it 🤔

Edited 15 September, 20223 yr by varooom

It is not there under Adaptations, and as I said the Coding-11 button is greyed out.

 

Weirdly, I just checked it out with Worth (a friendly RAC tech did it for me) and the diff press adaptation is not available there either. My engine is a CUUB 2015/2016 crossover and has 2 diff pressure switches not one.

 

Checking measured values now, they all seem plausible with engine off/on and minimal offset?

 

I think if the light comes on again I will replace both switches with proper VW ones. You just do not expect a replacement switch to be duff!

 

All good now, fingers crossed!

 

1 hour ago, varooom said:

Pukka (you'll have Jamie Oliver spinning in his grave) 😁
 

 

I don't think you are coding this change!

 

UDS Protocol (G450) procedure

Key ON, Engine OFF
[Basic Settings]
Select Adaptation of diff. pressure sensor particulate filter
[Go!] to activate the Basic Setting.
After the result of Finished Correctly appears click [Stop]

Select Resetting of learned values of difference pressure sensor
[Go!] to activate the Basic Setting.
After the result of Finished Correctly appears click [Stop]
[Done, Go Back]

 

 

 

CAN Protocol (G450) procedure

Instructions should be populated in a pop-up balloon when connected to the controller in question with VCDS.

Key ON, Engine OFF
[Coding-2] or [Login-II] button
Enter the code shown in the VCDS pop-up balloon
[Do It!]
Switch Ignition OFF for 30 seconds

After the key is cycled back on the adaptation should be completed. If it is not completed, proceed with the next steps:

These steps must be repeated 5 times.

• Ignition ON
• Wait 5 seconds
• Ignition OFF
• Wait 40 seconds
• Repeat 4 more times

 

5 minutes ago, Johnricketts said:

Weirdly, I just checked it out with Worth (a friendly RAC tech did it for me) and the diff press adaptation is not available there either. My engine is a CUUB 2015/2016 crossover and has 2 diff pressure switches not one.

Maybe this set-up doesn't require any such adaptation?

Are they not pressure sensors, rather than pressure switches? i.e. they actually output numbers

2 minutes ago, Johnricketts said:

It is not there under Adaptations, and as I said the Coding-11 button is greyed out.

 

Weirdly, I just checked it out with Worth (a friendly RAC tech did it for me) and the diff press adaptation is not available there either. My engine is a CUUB 2015/2016 crossover and has 2 diff pressure switches not one.

 

Checking measured values now, they all seem plausible with engine off/on and minimal offset?

 

I think if the light comes on again I will replace both switches with proper VW ones. You just do not expect a replacement switch to be duff!

 

All good now, fingers crossed!

 

 

I didn't doubt Coding II was missing, my point was that was for CAN network

Yours should be UDS, like it is in my own car.  You can see this on the top left of each module you enter (tip of the day!)

 

I also have the 2x DPF sensors (not switches) which has always been an oddity to me as to why this is.

One tube from each will head before and after the DPF, and the other side vents to atmosphere 🧐

 

My older cars (Passats) have been single DPF sensor, as it is on many cars.

1 minute ago, Breezy_Pete said:

Maybe this set-up doesn't require any such adaptation?

Are they not pressure sensors, rather than pressure switches? i.e. they actually output numbers

Identical to my 1.6TDI, 2x DPF sensors and only using a single pipe (like why!!!) 😆

Yes, they are analogue outputs (0-5v) not switches). I am also now of the opinion that these do not need adaptation!

 

All a bit confusing in the online manuals though as they still mention adaptation!

 

Now you have fitted and got more plausable results, what are your Soot Calculated and Measured values looking like now?

Less than 20g hopefully for both.

yep, down to 8g after forced regen