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-   -   Anyone with fault code P1552? (https://rennlist.com/forums/991-turbo/1110443-anyone-with-fault-code-p1552.html)

Jean 11-09-2018 02:53 AM

Anyone with fault code P1552?
 
My car has been running as if it had a mind of her own, very unpredictable limp mode under different conditions, and I am forced to switch off for a minute, then on again to get it going... sometimes code faults that get triggered are by the dozen, PDK, Pressure sensor, etc..

Its not a programming issue (I have a Cobb), it happens in stock mode too and cruising slowly on the road or at the track, with different fuels, programs and tires.. different elevations and temperatures... just random.

This code is for Intake Air control Valve according to some research.. however I believe these cars don’t have it, so what else? I am checking over the week end air leaks and piping at the IPD, and throttle body, hoping it’s related to that but I would be surprised if it was.

Anyone here experienced a similar situation, completely random CEL and going to limp mode?


Nanook 11-09-2018 08:40 AM

Possible battery related ?

aft86 11-09-2018 10:02 PM

Yes, maybe battery related.
As per the fault code book:

P1552
Diagnostic information - DME (DFI) control unit
Control unit function monitoring
Diagnostic conditions
• Ignition on > 10 second(s)
• then idling > 30 second(s)
• then engine speed > 1,000 rpm > 60 seconds with: • Vehicle standstill

Possible fault causes
• Power supply or ground supply faulty A See P1559
• DME (DFI) control unit software error D Reprogram

i - INFORMATION
• All calculations for functions in the control unit are monitored by a higher level unit.
• A fault is entered if monitoring detects implausible calculations.

Jean 11-09-2018 11:03 PM


Originally Posted by aft86 (Post 15421304)
Yes, maybe battery related.
As per the fault code book:

P1552
Diagnostic information - DME (DFI) control unit
Control unit function monitoring
Diagnostic conditions
• Ignition on > 10 second(s)
• then idling > 30 second(s)
• then engine speed > 1,000 rpm > 60 seconds with: • Vehicle standstill

Possible fault causes
• Power supply or ground supply faulty A See P1559
• DME (DFI) control unit software error D Reprogram

i - INFORMATION
• All calculations for functions in the control unit are monitored by a higher level unit.
• A fault is entered if monitoring detects implausible calculations.

Thank you :thumbup: so it’s either a power supply issue or need to replace the DME or reprogram.

Mind sharing the info source? Would like to check P1559 as well.

Kevin 11-10-2018 12:46 AM

Jean Here is P1559 (factory PIWIS) Grab a volt meter and measure your battery resting voltage. Then turn the key to first click>measure voltage >>if below 12.2 volts you might need a new battery
Diagnostic information DME
(DFI) control unit
Control unit restart during operation (warm reset)
Diagnostic conditions
Engine start
Possible fault causes
Vehicle electrical system voltage < 6 V during starting process (e.g. battery discharged or
faulty), e.g. due to contact resistance in the lines to the DME control unit.
Excessive difference in internal monitoring processes in the control unit, e.g. in case of
reversal of the engine's direction of rotation due to inadvertent shifting into reverse gear when
the vehicle is driving forward.
Fault setting condition(s)
This fault is entered if the DME control unit performs a restart during operation (soft
reboot/warm reset).

Jean 11-10-2018 04:10 AM

Thanks Kevin very helpful as always.

It all points to a DME issue, the battery is in very good condition. I did put the car in reverse mode sometime back while driving for a split second, seems it could be the issue as described above.

Question now is whether the local dealer can reprogram the DME or I will have to buy a new unit. I have a race in 6 days and would never get it back on time, they are extremely slow in ordering parts to this part of the world.

lowpue 11-10-2018 11:00 AM

I'd like to understand the conditions you put the engine in reverse, does PDK allow this....I would have thought there would be a software interlock?

Jean 11-10-2018 11:57 AM


Originally Posted by lowpue (Post 15422036)
I'd like to understand the conditions you put the engine in reverse, does PDK allow this....I would have thought there would be a software interlock?

Idiotic habit coming from my manual cars days of putting the car into neutral as I coast towards my pit garage. Once, before stopping completely, I shifted to R thinking I was still in Drive and was shifting it to Neutral, at very slow speed, the software does take care of it, it doesn’t engage.

Not sure that’s the problem still, so eliminating other potential issues such as cleaning the MAF and all turbo and Intake pipes, will reset codes, and then put it on a dyno tomorrow.

Kevin 11-10-2018 05:12 PM

Jean, I'd flash the ECU back to stock and then have your dealer reflash/update the ECU. If they brick the ECU it should only be 2 or 3 days out from Germany???

lowpue 11-10-2018 05:43 PM


Originally Posted by Jean (Post 15422112)

Idiotic habit coming from my manual cars days of putting the car into neutral as I coast towards my pit garage. Once, before stopping completely, I shifted to R thinking I was still in Drive and was shifting it to Neutral, at very slow speed, the software does take care of it, it doesn’t engage.

Not sure that’s the problem still, so eliminating other potential issues such as cleaning the MAF and all turbo and Intake pipes, will reset codes, and then put it on a dyno tomorrow.

I'd love to see some of your track videos...are they posted anywhere.

aft86 11-11-2018 12:01 PM

1 Attachment(s)

Originally Posted by Jean (Post 15421418)

Thank you :thumbup: so it’s either a power supply issue or need to replace the DME or reprogram.

Mind sharing the info source? Would like to check P1559 as well.

I found this pdf in the other forum I will not mention, which has the codes, symptoms, etc.

worf928 11-11-2018 10:16 PM


Originally Posted by aft86 (Post 15424063)
I found this pdf in the other forum I will not mention, which has the codes, symptoms, etc.

Excellent!

Thanks.

A/S 11-13-2018 02:59 PM


Originally Posted by aft86 (Post 15424063)
I found this pdf in the other forum I will not mention, which has the codes, symptoms, etc.

Thanks, this is very valuable.

Jean 11-14-2018 12:13 PM


Originally Posted by aft86 (Post 15424063)
I found this pdf in the other forum I will not mention, which has the codes, symptoms, etc.

Thanks for this..

Update, cleaned MAF, checked all pipes, IPD, turbo intake pipes (had some oil) and they did a pressure test, cleared all codes and reset it, then put the car on the dyno and there is a clear throttle shutdown at 6k RPMs.

Datalogs don’t show any timing pull, AFRs are perfect, and no other issues other than a sudden throttle shutdown and drop in boost to lower levels. It is not a mechanical issue. This happens with different maps and boost levels, always around 6K RPMs. Once it does this shutdown, all next runs (be it on track or dyno) the car doesn’t boost above 1.2 Bar or so, until it is reset and all codes cleared.

The car is going to the dealer tomorrow for a reflash to original factory maps and a full diagnostics..


siddharth.desai 04-07-2019 02:54 AM


Originally Posted by Jean (Post 15430398)

Thanks for this..

Update, cleaned MAF, checked all pipes, IPD, turbo intake pipes (had some oil) and they did a pressure test, cleared all codes and reset it, then put the car on the dyno and there is a clear throttle shutdown at 6k RPMs.

Datalogs don’t show any timing pull, AFRs are perfect, and no other issues other than a sudden throttle shutdown and drop in boost to lower levels. It is not a mechanical issue. This happens with different maps and boost levels, always around 6K RPMs. Once it does this shutdown, all next runs (be it on track or dyno) the car doesn’t boost above 1.2 Bar or so, until it is reset and all codes cleared.

The car is going to the dealer tomorrow for a reflash to original factory maps and a full diagnostics..



Any update to this, I just got the same error.


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