ECU Programming

[Camerons]

Has anyone reprogrammed their euc to get more HP and torque ?

[uncle_bob]

Originally Posted by Camerons

Has anyone reprogrammed their euc to get more HP and torque ?

Hi

Yup.

Done the above *and* met pollution specs? Nope

Done the above and not voided the warranty? Nope.

Bob

[Tronadora]

Originally Posted by Camerons

Has anyone reprogrammed their euc to get more HP and torque ?

I would be happy just to get higher RPM shift points. My first to second shift happens so quickly, especially when engine is hot and A/C is running, that it is downright dangerous to pull out in city traffic. Very sluggish! Dealer of course said no adjustment is available, so I'd also like to know how to improve this aspect of the programming.

[LB_3]

There are a number of Interstate owners here that have done this but we don't discuss it much on the forums since it can be an emotional topic for some.

There are a multiple places that do it from mild to wild. On the NCV3 you will need to remove the ECU and either mail it off to be reprogrammed or go to a shop that does this. I believe Protag even had his Mercedes dealer send his ECU off and reinstall it so it's not a guaranteed warranty violation.

Some tunes will just eliminate limp home mode caused by emissions failures. Losing speed on a highway can be dangerous so I would recommend this sort of upgrade since having a stuck egr valve is not an emergency but that 18 wheeler behind you might be.

As for performance tunes, so long as they can keep cylinder pressures within nominal operating ranges, it would be near impossible for a dealer to prove that your tune caused a failure. Many of the European versions of our vans have much higher HP and torque ratings so these mods can be done safely. As for their impact on the emissions I can only guess. But I suspect there is little impact short of wide open throttle when you're using that extra HP to accelerate up to speed on a short onramp.

Some tunes are done for economy. In these tunes they often reduce how much exhaust gas is sent back through the intake. This increases the exhaust gas temperatures and gives you more performance from less fuel. It increases Nitric Oxide emissions but reduces CO2 and other pollutants. Pick your poison I suppose.

If you're out of warranty and not in an emissions testing state, I wouldn't fault anyone for adding a few peak horsepower and torque to help get our heavy vans up to highway speeds a little faster.

[amirm]

I had mine done by these guys: https://www.renntechmercedes.com/ind...p-422tq-detail

Did a lot of research and all I read was positive about such tuning.

If you look at their dealer list, many are Mercedes dealerships: https://www.renntechmercedes.com/ind.../north-america

Other than pain the neck of removing the ECU because it is under the aux battery in the hood, everything has been super positive. The van went from lethargic and in my opinion unsafe (would scare the pants off of me to try to merge into freeway at times and have it struggle) to almost running like a competent car.

I suspect the lifetime of the engine is shorter with this change but I am fine with it. It is not like we are using it like a delivery truck day in and day out.

So if you can shell out $1,000, I highly recommend it.

[uncle_bob]

Hi

Ok, here's the warranty impact: Your engine will be dumping more "stuff" into the North American pollution gizmos. You get a nice long warranty on them. That may be different in Canada then the US, but I believe it's pretty much same same. If you have a warranty claim and the dealer runs a checksum on the ECU, they will know it's been fiddled. No need to pull it. You can do it with it in place. Will they be that smart? Who knows ....

Bob

[Protagonist]

I did take my NCV3 Interstate to my Mercedes Benz dealer. They removed the chip and FedExed it to RennTech. They didn't even have to call for pricing, because the price of a RennTech ECU tune is already in the MB shop manuals. RennTech is an authorized Mercedes Benz upfitter, meaning that MB has approved the RennTech ECU tune and it will not void the warranty. They will not reset the ECU back to factory specs when they perform service— but even if they did, RennTech would redo the ECU tune for free.

The engine runs leaner, and a little bit hotter, by about 10°F, but has never overheated because of the ECU tune.

Horsepower, torque, and even MPG are all improved, most of the time. The horsepower and torque are easily noticed when I merge onto a highway while pulling my Honda, or when I ascend steep grades when pulling the Honda.

The biggest gain in fuel economy occurs at about 45mph, where I get about 5mpg more. Below 35mph (in town) there's no change that I can see, because with all of the traffic lights in town, fuel economy varies widely from one day to the next anyway. Doesn't take idling at very many red lights to torpedo fuel economy. From 45 to 65, I see a gain of 1-2mpg, even when pulling a 3300-pound Honda Fit. Above 65mph, fuel economy goes way down even when NOT pulling the Honda. At 70mph, I see about 3mpg less than before.

Also, if I have to stomp the accelerator to gain speed in a hurry (merging onto the highway on a steep grade in heavy traffic), the dashboard display shows an immediate drop in fuel economy, but that's to be expected. It's worth the hit in order to accelerate 1400 pounds of metal (van plus toad) to highway speeds before you get to the end of the on-ramp.

My Honda owner's manual says not to tow if faster than 65mph anyway, so I just mosey down the road at 60, proudly displaying a bumper sticker that says "I'm Retired. Go Around Me." I'm retired, it's an RV. Why should I be in a hurry? Slow down and enjoy the drive— and enjoy 19+ mpg while towing my car.

Can't say whether the ECU tune meets emissions specifications. Probably not in California, where vehicles are required to exhaust cleaner air than they suck in (that's right, in some California cities, the ambient air doesn't meet emissions requirements, and there have been tests to prove it). Fortunately, that's a non-issue for me because Louisiana doesn't test emissions except for vehicles registered in the Baton Rouge metro area, which mine isn't. But from an intuitive standpoint, if the air-fuel mixture is leaner at most speeds, emissions should be reduced because you get more complete combustion.

[Boxster1971]

Originally Posted by Tronadora

I would be happy just to get higher RPM shift points. My first to second shift happens so quickly, especially when engine is hot and A/C is running, that it is downright dangerous to pull out in city traffic. Very sluggish! Dealer of course said no adjustment is available, so I'd also like to know how to improve this aspect of the programming.

The simple fix for this is to shift your van manually. The automatic in Sprinters is about the easiest automatic to shift manually that I have ever driven. I shift mine manually all the time, especially in traffic where I might need a quick burst of power. The other alternative is to floor the accelerator when you need more power it will then down shift. But if you don't want to drive it that hard just shift manually using the tachometer to keep engine in the power band above 2,000 rpm.

[Camerons]

Thanks for all the help. Ontario does have a drive clean test. Relies on reading the EUC. I don't think they check to see if it has been tampered with. I will call a local renntech installer and see. Appreciate all the advice . Cam

[uncle_bob]

Originally Posted by Camerons

Thanks for all the help. Ontario does have a drive clean test. Relies on reading the EUC. I don't think they check to see if it has been tampered with. I will call a local renntech installer and see. Appreciate all the advice . Cam

Hi

If MB authorizes the "tune" then it's not tampering. You are covered from pretty much any nasty outcome.

Bob

[Protagonist]

Originally Posted by Boxster1971

The simple fix for this is to shift your van manually. The automatic in Sprinters is about the easiest automatic to shift manually that I have ever driven. I shift mine manually all the time, especially in traffic where I might need a quick burst of power. The other alternative is to floor the accelerator when you need more power it will then down shift. But if you don't want to drive it that hard just shift manually using the tachometer to keep engine in the power band above 2,000 rpm.

I believe the RennTech ECU tune does alter the shift points. But I can't really remember; I had the ECU tune done about 4 years ago, and some of those brain cells have gone bye-bye. All I know is, when I need my Interstate to get out of its own way, it now has the acceleration to do it.

You know what they say, "When the memory goes, you can just forget it!"

[Camerons]

Protagonist is right. Tuning is a good thing. Better mileage (as long as you use cruise). Better acceleration. No limp mode. No speed limiter.

The other advantage is that some tuners know a LOT about the sprinters. They know what is going to break next. The same things break on all sprinters. They can eliminate some of these fails with software. The van won't be legal however it will pass emissions test.

After the first 1000km I can report 3 l/100 better fuel. Passing on a two lane road is possible. It can now go 150kph. The tuner did not recommend an aggressive tune as the airstream is heavy. An aggressive tune will stress the power train too much and blow the torque converter. The tune they did works well for me . Love that I won't have to limp home. Did that once with a blown O2 sensor. Never again. Monetary Payback period for me is 40000km and the fuel savings pays for the tune. Smiles are instant when you press the accelerator. I would highly recommend a tune

[amirm]

On the first to second shift, we have a steep driveway. I always manually shift it into first gear. But despite that, as soon as we go 10-20 yards up the driveway, there is a distinct shift into a higher gear causing all the torque to be lost. Anyone know what is going on? I don't think the RPM is getting too high for it to override but I have not looked.

I have only gotten hit with that in traffic once. Otherwise, it pulls with authority with the tune. The scary situation where you want to get out and push the thing as you merge on the freeway , is all gone.

[Boxster1971]

Originally Posted by amirm

On the first to second shift, we have a steep driveway. I always manually shift it into first gear. But despite that, as soon as we go 10-20 yards up the driveway, there is a distinct shift into a higher gear causing all the torque to be lost. Anyone know what is going on? I don't think the RPM is getting too high for it to override but I have not looked.

I have only gotten hit with that in traffic once. Otherwise, it pulls with authority with the tune. The scary situation where you want to get out and push the thing as you merge on the freeway , is all gone.

If you are manually shifted into first gear the change you are experiencing is the lock-up of the torque converter. When it is unlocked there is a power gain from the torque converter that goes away when it locks up. Try holding the rpm just below the point where you feel that lock-up. That might improve your hill climbing.

[amirm]

Originally Posted by Boxster1971

If you are manually shifted into first gear the change you are experiencing is the lock-up of the torque converter. When it is unlocked there is a power gain from the torque converter that goes away when it locks up. Try holding the rpm just below the point where you feel that lock-up. That might improve your hill climbing.

Ah, didn't know that. Thank you.

[felixkagi]

Originally Posted by Camerons

Has anyone reprogrammed their euc to get more HP and torque ?

Before venturing into chipping your rather expensive MB Sprinter engine, you would want to read below article (and a few more written in german where much of this ECU "tuning" comes from).

https://outbackjoe.com/macho-diverti...o-diesel-chip/

[felixkagi]

Originally Posted by Protagonist

The article is not entirely factual................. It's an RV, not a delivery van!

Well, the article is just an opinion and to the writers defense, he makes mention of why one might want to have a "tuned" diesel engine. However as he states; OEM engine tuning is a compromise and a manufacturer would know best how to satisfy all points.

Correct me if I am wrong, I believe you mentioned in one of your posts that you noticed a 10F coolant temperature increase?

In any case, the article has many great points on how to stretch trouble free driving with ANY vehicle. I for one would no longer purchase a vehicle that has or had a tuned ECU installed.

[Protagonist]

Originally Posted by felixkagi

Before venturing into chipping your rather expensive MB Sprinter engine, you would want to read below article (and a few more written in german where much of this ECU "tuning" comes from).

Despite what the article says, I am perfectly happy with my RennTech ECU tune. I wouldn't go back to the factory ECU tune even for a double-your-money-back refund. If anybody asks me if they should get it done to their Airstream Interstates, I will still tell them "Yes" without hesitation.

My Interstate, just like almost every RV, spends a lot more time parked than it does moving, and the mean time between failures is not an issue for most engine components on a vehicle that only racks up 10k miles a year and hardly ever exceeds 60mph.

But the main advantage of the ECU tune, the ability to accelerate like you mean it, when you need to, far outweighs the amount of added engine wear from having the ECU tune.

[Titus]

I went to the RennTech website and see no mention of the device eliminating the limp home mode. Are you sure that it eliminates limp home? Which ones? If eliminating LH is my goal, wouldn't it be much cheaper to use an OBD device to override the LH?

[c21]

I'm surprised to hear of Protag's positive results with chips. I have chipped 3 vehicles and in all 3 instances wound up with a bit more power and a bit worse fuel economy. My stock AI outclimbs everyone in our rv caravans and far exceeds everyone's mileage so no chips for moi!