P1598 and P0238 on my Peugeot 407 2.0 HDi

[ijwtsh]

Hello everyone. I have P1598 and P0238 on my Peugeot 407 2.0 HDi.
These errors have appeared only after a stage 1 remap that I did in some other city and I couldn't stay there for long, only for a day (I'm from Romania).
Now, is it true that these errors are not related? P1598 points to the electrovalve on the thermostat (my car is from 2004), and I understand that from 2005 onwards, the thermostat was different, it does not have an electrovalve anymore because it malfuctioned so often. Anyways, I don't think anything is wrong with my car for now, because the temperature is 85-90 degrees, so it doesn't affect me in any way.

What I'm more concerned about is P0238. The effect of this is overboost, in 4th gear at 2500-3000 rpm, but I have also experienced it in 3rd gear, 3500+ rpm. I get the "Check engine" message on the computer, but there is no limp mode (on other posts I saw that the car enters limp mode and resets after restarting the car. This is not the case here.). But I do feel that in the 4th gear it accelerates slower. Now, on the internet many people say that some cars need a wastegate adjustment after remap, but I don't know why. The car seems to pull much better now, turbo lag is reduced and until the 4th gear it runs great.

The guy that did the remap said it's either the turbo electrovane (which I changed and the error did not go away) or a sticky vane. I (well, the guys from the car service) also did a vacuum test on it and everything's ok. The turbo has variable geometry and the car has ~303k km (188k miles according to Google). That is pretty much, to be fair. I don't think the turbo has been cleaned ever so far (I only bought the car when it had ~293k km).

Some guy at some other car service started the car and looked under it to see some kind of rod (I hope that's the correct term in English, sorry if it isn't) that is supposed to move the variable geometry (Question: variable geometry = VNT?) and I saw that when the car started, the rod moved by a bit upwards. He told me that VNT is working. What seemed odd was that he only checked it by starting the car, but the problem I experience was at higher revs, so maybe it works but not all the way?

Anyway, before I go back to that other city to the guy that did my remap, I want to rule out every other possibility, because the city is a bit far from me and I kinda trust the guy, since there are so many good reviews on his Facebook page from other people that got a remap from him.

Thank you guys and sorry for the long post!

[GiveMeABreak]

You need to provide your VIN for me, so I can determine the exact engine you have and relate these codes to the specific engine management system you have. Obviously we can't comment directly on your specific remap - as we have no idea what parameters they have changed.

[ijwtsh]

Hello. My VIN is VF3**************[VIN obfuscated, can be read by forum staff]. I saw on the tester that my turbo is overboosting, I just need help diagnosing if it's sticky vanes or what else before saying that the remap is the issue... Thanks

[GiveMeABreak]

The first fault has no description - but could be a thermostat / short circuit.
P1598: Cooling circuit by-pass electrovalve

Fault Code: P0238 Description of Fault: Turbocharger pressure signal: Short circuit to positive. The Voltage of turbo air pressure signal is higher than 4.80 V (Turbo pressure greater than 2530 mbar) for 2.5 seconds or 125 engine revs. Engine warning lamp will usually be lit when this error is present. Conditions for Fault to clear: Ignition on Downgrade Modes whilst Fault is active: Deactivation speed limiter until the next time the ignition is switched on Deactivation cruise control until the next time the ignition is switched on Cutting of the EGR valve: Fuel flow limitation Deactivation of the regulation of the turbocharging Symptoms: Lack of power, Slightly higher fuel consumption, Noise. Suspect Areas: Turbocharging pressure sensor Turbocharger position copy sensor Turbocharger blocked in position: Maximum turbo Turbocharger: Damaged Turbocharging pressure sensor

So looking at the third possibility above - 'Turbo blocked in Max. Position - Max Turbo' is that as a result of the mapping......?

[ijwtsh]

Thanks for the info, it's all very useful. Regarding your last comment, can this be because of sticky turbo vanes, not because of the mapping? Thanks!

[GiveMeABreak]

Have a look here - some have had results with a double dose of diesel cleaning solution to free them up - see if that fixes the issue before anything else - as that might unstick them.

https://www.briskoda.net/forums/topic/1 ... es-solved/