ECU Programming

[Titus]

c21bill
Agree with your comments on power. I have been satisfied with acceleration on on-ramps and hill-climbing ability during mountain driving. (For reference our other vehicles are a Prius and a 4 cyl Camry, so we are not used to squealing tires!). I have not seen a need to chip from a power perspective and you'd never recover the chip cost if doing it for an improvement in fuel economy. My sole reason for chipping is if it lets me avoid the horror stories of limp home. I want the dash warning of a problem, but not the 25 mph limp home - a combination of what MB decided to do and want EPA requires.

[c21]

Originally Posted by Titus

c21bill
Agree with your comments on power. I have been satisfied with acceleration on on-ramps and hill-climbing ability during mountain driving. (For reference our other vehicles are a Prius and a 4 cyl Camry, so we are not used to squealing tires!). I have not seen a need to chip from a power perspective and you'd never recover the chip cost if doing it for an improvement in fuel economy. My sole reason for chipping is if it lets me avoid the horror stories of limp home. I want the dash warning of a problem, but not the 25 mph limp home - a combination of what MB decided to do and want EPA requires.

Good point!

[c21]

Originally Posted by Titus

c21bill
Agree with your comments on power. I have been satisfied with acceleration on on-ramps and hill-climbing ability during mountain driving. (For reference our other vehicles are a Prius and a 4 cyl Camry, so we are not used to squealing tires!). I have not seen a need to chip from a power perspective and you'd never recover the chip cost if doing it for an improvement in fuel economy. My sole reason for chipping is if it lets me avoid the horror stories of limp home. I want the dash warning of a problem, but not the 25 mph limp home - a combination of what MB decided to do and want EPA requires.

It would be nice to eliminate the potential for limp home mode without the performance mods. I sure don't want to increase the operating temp. and I have no need for the increased power. If you run across anything please share.

[Boxster1971]

Originally Posted by 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?

I doubt that any ECU tuning will eliminate Limp Home (LH) modes. They are designed into basic programming to prevent engine or transmission damage and to ensure environmental compliance.

[Titus]

An e-mail to RennTech confirmed Boxter1971's suspicion that the RennTech does not eliminate limp home. I read something somewhere (Sprinter forum?) suggesting that some chip did so. I would value LH elimination more than a power upgrade. I am not sure that LH is any more 'basic' to the ECU than the torque characteristics - just maybe not as saleable to the general public. One can identify with a power and (possible) fuel economy increase, but not so much with solving a LH problem that may not ever rear its ugly head.

[amirm]

My guess is that Renntech's tuning is changing the mapping tables only. I say this because an ECU firmware upgrade by Mercedes in my last service did not undo their changes. Modifying other parameters like Limp Home may require actual reverse engineering and changing of the firmware which they don't want to or capable of doing.

[felixkagi]

Originally Posted by amirm

My guess is that Renntech's tuning is changing the mapping tables only. I say this because an ECU firmware upgrade by Mercedes in my last service did not undo their changes. Modifying other parameters like Limp Home may require actual reverse engineering and changing of the firmware which they don't want to or capable of doing.

http://ecuchipsnewzealand.ecuchipslt...ur-vehicle.pdf

........an article that explains different types of tuning and why firmware upgrades may not detect or alter aftermarket engine tuning. Though in any case, all tuning increases fuel rail pressures and/or control the length of the injection pulse, i.e. add more fuel.

These guys obviously are trying to sell something, so form your own opinion.

[amirm]

Originally Posted by felixkagi

http://ecuchipsnewzealand.ecuchipslt...ur-vehicle.pdf

........an article that explains different types of tuning and why firmware upgrades may not detect or alter aftermarket engine tuning. Though in any case, all tuning increases fuel rail pressures and/or control the length of the injection pulse, i.e. add more fuel.

These guys obviously are trying to sell something, so form your own opinion.

If you go to Renntech web site and see their resellers, you see that most are Mercedes dealers: https://www.renntechmercedes.com/ind.../north-america

Mercedes-Benz of Anchorage
Mercedes-Benz of Rocklin
Mercedes-Benz of Westminister
Mercedes-Benz of Colorado Springs
Mercedes-Benz of Littleton

The list goes on. Indeed there are more Mercedes dealers than not!

They also have a long history of tuning Mercedes cars.

Mercedes also sells similar engine in their sedans with far more horsepower and torque.

For these reason, I am not worried about the issues they raise.

When I did my research on whether dealers will detect the change and refuse service, good point was raised as to why that would be for their benefit? They could go ahead and service the engine and get paid by Mercedes. Or make nothing by refusing the warranty service and making the customer upset.

Combined with the fact that I already had my first service and they did update things for emissions, I feel 100% safe and happy with this modification. I see nothing but upside in it.

[Camerons]

The folks who did my tune can eliminate limp mode without any power mod. Find a good tuner and they can fix a lot in software.

[Boxster1971]

Originally Posted by Camerons

The folks who did my tune can eliminate limp mode without any power mod. Find a good tuner and they can fix a lot in software.

Tell us who did it....

[Camerons]

They are in Oakville ontario. You can ship them your ecu. Like renntech or drive there. Great service.

[Camerons]

Www.chiptuning.ca

[Boxster1971]

Originally Posted by Camerons

Www.chiptuning.ca

Thanks

[ben322]

Steady state between Montreal & Quebec City

[Boxster1971]

Originally Posted by ben322

Steady state between Montreal & Quebec City

Is that at 55 mph, with tailwind and downhill?

[ben322]

Just above 55mph, (91kmh), on level ground with little to no wind. I've found that this is the sweet spot just under 2200rpms. Drops to about 24 @65.

[BurntAsphalt]

Does that tuning delete the #start countdown as well? That MB policy is more dangerous than Limp Home mode. Being stuck in middle of nowhere with limited starts is a quick way to ruin a vacation, not to mention the safety issues.

[felixkagi]

Originally Posted by BurntAsphalt

Does that tuning delete the #start countdown as well? That MB policy is more dangerous than Limp Home mode. Being stuck in middle of nowhere with limited starts is a quick way to ruin a vacation, not to mention the safety issues.

concur with this statement, especially when you have 4 starts left and a large Mercedes dealership tells you "we don't work on Sprinters on Fridays"

Drove for 3.5 hours to the next one, was there around 3:45PM with two starts left and lucky was out by by 5:30 with one new NOx sensor.

[Camerons]

You can work with the tuner you selected and send them your ecu (its under the spare battery on the driver side under the hood). Or bring the airstream in and they will take it out. You can ask for more HP more torque. No limp mode. No speed limit. All or any combination of these. Each tuner will recommend something that works for you. Mine did not recommend a full stage two tune and the airstream is much heavier than a normal sprinter. I am happy with the increase in power torque no speed limit and never have to worry about limping

[amirm]

I highly recommend having someone else take the ECU out. It is a huge pain to do it yourself. There are blind bolts that are darn near impossible to loosen. I hated taking it out and putting it in.