r/ECU_Tuning

Hey, long thread ahead.

I own a W212 E350 2010 (My lab rat), and I work in IT and I was thinking to get into cars coding and tuning as a side hustle to make some extra money.

I've learnt some main concepts:

\- Features variant coding

\- SCN coding

\- Remapping

\- The differences between C4/C5/C6

\- The softwares Xentry/DTS Monaco/Vediamo

My questions are for those who can help:

1. Is C6 good enough? From what I learnt C6 is an after market invention and it can't do everything, but it seems to be the most popular and most spread world-wide so i need to know the limitations i will run into if i get one.

2. What are some advise and tips from people in this domain? Is it good? Is it worth it? What should I keep in mind? Whats something you wish you knew before you get into this domain?

3. Is my laptop going to be enough (along with my multiplexer) or will i need more advanced gear?

I was wondering if a stage 1 tune would work on a 2025 Celerio. I had a stage 1 tune done to my Honda amaze and now it performs better in the mid ranges, the throttle response is better in the lower rpms which was lacking when it was stock. Hence considering a tune on the celerio. Please advise if any of you has done this on a similar car like alto, celerio etc.

I have a 2014 CLA 45 running a stage 1 tune, whenever it gets really hot outside the car just shuts down and we get a “fuel pump low voltage” code, we have changed the fuel pump and the fuel pump control module, but still whenever it gets hot outside it just stalls and runs for about 20 seconds.

We have tested it when the temperatures are cooler and it runs for 2+ hours without issue. The shop says that the only other thing that could be the culprit is the ECU tune.

Is it possible something is messed up in the remap file that makes the car shut down whenever the ambient temperature is high?

so i was flashing my golf r with a new tune and my laptop died halfway through. yeah i know. stupid. now the car wont start and the obd port is dead. no communication with the ecu at all.

i've been reading up on recovery options but everything i find is for older ecus. this is a bosch med17.5.5 i think. heard you can boot mode it but i dont have the tools for that.

anyone here done this on a mk7? how much of a headache am i in for.

Hey guys, I've been battling with this issue for over a year. I have not done almost any modifications to the car. Only had switched original lights with chinese DRLs in the front (already put back the originals), changed the stereo to a Pioneer (install is good) and went to a Dyno/Tuner who says he has ONLY touched cells that are above 60% power (fuel pressure target).

VEHICLE

- Mitsubishi L200/Triton, 4N15 2.4 diesel, 2021, manual gearbox

- Base/DOC-only emissions spec: no DPF (ECU coded "Not Present"), no SCR/AdBlue, no NOx sensor, no EGR-gas-temp sensor

- Aggressive aftermarket remap (approx +55% hp / +70% torque)

- Note: CAN gateway module is absent (harness cut, timing unknown)

SYMPTOM

- Rough/hunting idle ONLY when fully warm (~85C). Cold idle is fine.

- Instantly smooths the moment ANY load / idle-up is added (hazards, brake, steering, A/C).

- ZERO stored/pending DTCs, no warning lights.

MEASURED (LAUNCH scanner, live data, warm idle ~800 rpm). It cycles between two states on its own, and I have BOTH target and actual on screen:

SMOOTH ROUGH

Rail pressure actual 35 MPa -> 119-123 MPa

Rail pressure TARGET 35 MPa -> 120 MPa (target moves WITH actual)

EGR position ~70% -> 0% (shut)

EGR target ~70% -> 0%

Intake throttle 18 deg -> 82 deg (choked) [1308mV -> 4180mV, linear/healthy]

Main inj timing -4 deg -> -6 deg (retarded)

Pilot qty (pre) 1.9 mm3 flat-> 2-3.4 mm3 HUNTING

Main qty (final) 10.5 flat -> 8.5-10.5 HUNTING

HP pump (SCV) target 1775 mA -> 1625-1675 mA

All six actuators step together and revert together. Rail target = actual in BOTH states (no control error, so it's commanded, not a runaway). The roughness is the pilot/main quantity hunting in the high state.

WHAT I READ INTO IT

Looks like the ECU is commanding a warm-idle heating/rich strategy: less air (EGR shut + throttle choked) + more fuel (rail up, post-inj) + timing retard = dump heat / go rich in the exhaust. On a DOC-only truck there's no

DPF/LNT/SCR that should need this at a warm idle, which is what makes it odd. Target=actual everywhere means the pump/SCV/rail sensor/injectors are all just obeying — not failing.

QUESTIONS FOR THE HIVE

1. Anyone recognize this exact 6-actuator warm-idle signature on a 4N15? Is it a known cat light-off / LNT-purge / de-NOx strategy, or a mis-gated enrichment?

2. Why would a base DOC-only cal command it at all — cross-market/wrong base file, or a real function?

3. Anyone map-diffed a 4N15 remap and seen the enable threshold / mode tables for this? Trying to confirm before a stock-flash test.

All the help is greatly appreciated. By the way this engine is kind of similar to Toyota's Hilux, also uses DENSO pump and and so on, so it should be similar setup.

https://preview.redd.it/cr3qwwrt7bbh1.png?width=973&format=png&auto=webp&s=50944da74dcf420db9162f0c7c3da64386e0b4f7

Hi guys,

Wanted some advice/help.

I had my 2019 VW Golf GTI Performance 55000 miles Automatic just suddenly lose power on me while driving last week, still had the dash on and lights but couldn’t gain power and shift gear to D. Opened the bonnet and noticed my relay was making a clicking noise, I replaced my relay with a genuine VW part brand new and still same clicking noise & wouldn’t start.

Had a few mechanics including one with official VW scanning tablet come out and they said that the ECU is faulty/damaged.

I had an auto electrician come out too who inspected all the wires and electrical components and he took the ECU out and showed how it rattles once shaken, as if something is inside loose.

He also scanned the vehicle and came up with the following fault code P086A00- ECM, PCM Power relay deenergized performance too early.

Also, when the relay is in the vehicle the brake lights are off, whenever I remove the relay all of a sudden my brake lights come on as if someone is pressing the brake. It is really weird.

I sent my ECU in for them to repair but unfortunately they couldn’t test it and therefore couldn’t repair it.

I am not stuck with either buying a brand new ECU (£1700 quote from VW)

Or, buying a used one for £350 which includes flashing over previous data from my damaged one and all coded correctly.

I need some advice please, how reliable are used ECUs given they have been coded correctly?

P.S, my car was NEVER mapped, no mode, & I drive normally don’t rag it.

Could anyone recommend an ECU with good programmable capabilities and open-source support?

I plan to LS swap an LS3 or 9 into a Subaru Brat. Don't have much ECU programming experience but I have loads of experience programing microcontrollers for trade.

Hi everyone I have been hearing a lot about PowerHouse Tuning, does anyone know anything about them and has already tuned their car with them?
Their IG is: PowerHouse.Tuning

Hello everyone,

I’m just starting to get into tuning cars, and I’ve been looking into two tools: the KTAG 200II and FormulaFlash. I’m not sure which one to choose or which one is considered better, especially for someone who’s just starting out.

If anyone has experience with either of these tools, I’d really appreciate your thoughts. Also, if you have any other budget-friendly tool recommendations that are reliable and good for beginners, I’d love to hear about them.

Thanks in advance!

I own a 2014 Audi S5. Current performance mods are only a 034 Stage 1 E93 tune and CTS Cold Air Intake.

When i was completely stock, launch control would work as follows. Turn traction to sport, hold brake in, press gas, climb to 3k rpms, then launch. Simple.

BUT now, after my tune my launch control is weird. I do the same as usual and my rpm caps at literally 1k. I have googled and googled, i have tried using traction completely off instead of sport, obviously my cars drive select is dynamic/S. I don't understand why it just hits 1k and wont go further after my tune, it's like the launch control is useless.

Any suggestions on how to fix? Is it worth re-flashing my car?