Limp Mode and Tuning Box

[mk4gtiturbo]

I've had a DTUK CRD3+ on my car for a year now with no problems, through the hot and the cold, but recently I have had a spate of Limp Modes.  First time a garage read Boost Sensor and cleared it, Second time was a couple of days after and it cleared itself, now third time (this morning) it was in Limp Mode when I started it and has cleared itself.

 

Anyone else suffer from this?  I'm assuming its the tuning box.  Do I just get a code reader and keep clearing it or does it need a new sensor?

 

[octavia5]

Doesn't the DTUK come with an eliminator connector to bypass the box and return the car to normal - easy check is to insert the connector and see if the box is causing the problem, if so try turning the settings down a notch and see if the problem still occurs.

 

Could be plugs or sensors, getting a reader is an idea but to find out what the problem is not to just keep clearing codes as that could lead to a major failure in future.  How many miles, how old, how do drive it?

[j1mg]

I took mine off for this very reason. Was great for about a year and them made the car unreliable, turning the car off and back on when it was at temp seemed to clear it at first, but it got worse and worse.

[mk4gtiturbo]

32 minutes ago, octavia5 said:

How many miles, how old, how do drive it?

 

56k, 14 plate, Only short miles now but does a longer journey every couple of weeks.

 

I have had the DPF light a couple of times and now this, it's a shame as I still like the car and can't think what I'd change it for but this might be the end!!  Need the same car but petrol!!

[themanwithnoaim]

No, you need a 245 mate

[Yaumeister]

My 1.4 TSI also suffered from "reduced performance" mode, due to manifold pressure / boost sensor signal too low. VCDS error below.

 

This happened several times during the recent heatwave, and the car has behaved itself since the weather has cooled down again, so I'm guessing hotter temp = thinner air may be the cause?

 

Feel free to correct me if I'm wrong, but I think the tuning box in simple terms lowers the boost reading, tricking the ECU to put out more boost. The map may be slightly too aggressive for the exceptional hot weather (thin air), so the box gives too low of a signal which the ECU then flags, and puts the car in "protected" mode.

 

20120 - Manifold Pressure / Boost Sensor (G31) 
          P0237 00 [036] - Signal too Low
          Intermittent - Not Confirmed - Tested Since Memory Clear
             Freeze Frame:
                    Fault Status: 00000001
                    Fault Priority: 2
                    Fault Frequency: 3
                    Mileage: 67016 km
                    Date: 2018.08.02
                    Time: 11:42:31

                    Engine speed: 1005.50 /min
                    Normed load value: 23.5 %
                    Vehicle speed: 0 km/h
                    Coolant temperature: 81 °C
                    Intake air temperature: 47 °C
                    Ambient air pressure: 1010 mbar
                    Voltage terminal 30: 12.250 V
                    Unlearning counter according OBD: 40
                    Charge air pressure specified value: 449.92 hPa
                    Air filling: specified value: 26.81 %
                    Charge air pressure: actual value: 192.42 hPa
                    Engine torque: 11.9 Nm
                    Mass flow through throttle valve: 15.3 kg/h
                    Relative load value: 24.96 %
                    Charge press. ctrl.: spec. value: 0.0 %

 

 

[Gadget007]

I have had limp mode occur with the DTUK box, in the end it turned out to be a problem with the plugs, the fuel pressure plug wasn't making secure contact

[themanwithnoaim]

It's generally sensitive sensors, you gotta remember, the box is tricking the ECU & therefore, faults will occur.

 

Most of the time, a decent mechanic can find the sensor for you, it's just a price to pay for NOT having a TD1 Flag from a remap

[Chimble]

On 20/08/2018 at 11:09, mk4gtiturbo said:

I've had a DTUK CRD3+ on my car for a year now with no problems, through the hot and the cold, but recently I have had a spate of Limp Modes.  First time a garage read Boost Sensor and cleared it, Second time was a couple of days after and it cleared itself, now third time (this morning) it was in Limp Mode when I started it and has cleared itself.

 

Anyone else suffer from this?  I'm assuming its the tuning box.  Do I just get a code reader and keep clearing it or does it need a new sensor?

 

Have you had the MAP sensor replaced. The original one was known to develop a fault at some point. My car is a 2014 vRS tdi and the sensor failed a year ago. Replaced under warranty. The car has been fine ever since.

[KarlO3V5]

I had some issues with mine - even with the blanking plug connected. Got in touch with DTUK and they swapped out the unit. Been fine since.

 

Running a +2 always caused issues for me. Back on 2+1 and it runs like a dream - no surging and pulls like a train. Time for a 0-150MPH video on a nice open private road.

[stever750]

I've run mine for last 10-12k mostly in P2 0 setting. I had the dreaded coil warning lamp come on in France earlier in the year when I started the car, and eventually had to turn the box off to clear it. Turned it back on when e got home, and fine after that, even ran it for around 3-4k in P2 +1 until it went into limp mode whilst overtaking, not good. It's been back on P2, 0 since then (around 3k miles ago) without any issues at all. I've just turned it up to +2 to see what it's like, but I won't leave it there for any longer / overtaking critical journeys as I just can't trust it. My bum dyno tells me +2 is noticeably stronger than 0 but not remotely worth the extra risk. I judged that the slight extra go in +1 mode over 0 was probably as much placebo as it was real (can you really detect a ~5bhp increase? I doubt it).

 

I did read on another thread somewhere that applying some electrically conducting grease to the terminals make a big difference to the system reliability, but if that's the case then why do the OEM connections not suffer from similarly unreliable connections, unless the DTUK connectors are inferior?

 

 

[toni8b]

I got a feeling than coil light likes to appear on TDI engines when you try booting it and its time to regen which has not been done for a long time.

[JohnnyType2]

On 21/08/2018 at 13:34, KarlO3V5 said:

I had some issues with mine - even with the blanking plug connected. Got in touch with DTUK and they swapped out the unit. Been fine since.

 

Running a +2 always caused issues for me. Back on 2+1 and it runs like a dream - no surging and pulls like a train. Time for a 0-150MPH video on a nice open private road.

i have a feeling the wiring might be an issue on some units. i had a friend had issues with dirt/water in some of the connectors. I always start with cleaning reseating the connectors with electrical contact spray. Sayng that i have had no issues so far with this CRD3+

 

 

[gman1967]

Having had 60 plus cars over the years and a lot of tuning going on (some good, some not so good lol) an observation...

 

Almost without exception, as soon as connectors are touched and alternatives plugged in, problems can and do arise. May seem everything is fine and that satisfying "click" as they push home is heard, but connection is not as reliable as original. 

 

What i found to resolve most issues was good old cable tie. Not radially around the body where the connectors mate, but longitudinally from end to end. 

 

Not claiming it as miracle cure - modern cars need an electrician, not a mechanic, but easy to do and if it works, result

[Genoa1893]

On 22/08/2018 at 16:38, stever750 said:

I did read on another thread somewhere that applying some electrically conducting grease to the terminals make a big difference to the system reliability, but if that's the case then why do the OEM connections not suffer from similarly unreliable connections, unless the DTUK connectors are inferior?

 

 

 

The trick of applying insulating, not conducting grease, is well known and generally applicable to all connectors.

 

http://forums.tdiclub.com/showthread.php?p=729585

 

HTH,

 

[Gadget007]

I got some conductive grease and put the smallest blob on every pin on each connector, and have noticed that the car is more refined now