computer update=reduced mpg

[superdave]

please help me figure this out... i bought a new 1999 3500 ram with cummins and auto tran. . after about 6000 miles i was getting 19. 8 or 19. 9 mpg at high speed hiway driving... about 16. 8 hiway with a load ranging from an empty 16' trailer to a 36 ft travel trailer... took the truck in for minor warranty work and the dealer "updated" the computer... after that i only get 15. 6 empty hiway driving and 12. 2 loaded hiway... . i certainly did not gain any more power... the propaganda sheets for the dodge cummins clearly states they meet all fed guidelines for emissions... . the dealer stated the update was to bring the engine into emission requirement. . ????? why does the advertising state it is in compliance???? any others had this problem?????

 

[Bob Wagner]

Superdave,Which TSB did you have done?

Thanks,

 

[jstyer]

I had the same thing happen with my '99 before I traded it in my '01 and I was not the only one. I met a fellow from Pennsylvania at a truck stop who asked me if i had my truck into dealer and "updated" because he had and he also saw a great decreasse in mileage. I don't know what TSB was used because it was in the shop for something else at the time. YOU ARE NOT ALONE!!!

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'01. 5 2500 QC 155"WB, White, 4x4, ETH/DEE, 4. 10 LSD, SLT, All power, Trailer , Plow Prep and Camper Special Group, Keyless Entry, Flip-up Towing Mirrors, Lund Window Deflectors and Running Boards, Profile Plus Bug Shield, Century raised top cap, PacBrake,Banks Git Kit, Banks pyro & boost guages and Auto Meter fuel pressure guage, 35 foot Hitch Hiker 5th wheel.

 

[MidwestMotorman]

I had the exact opposite happen on my 99. I saw twelve loaded and 15 highway. It went to 23 towing and 19 highway afterward. I can not give the TSB because my truck was also in for something else.

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99 2500 QC longbox, SLT, 4x4, 24V Cummins, 5 spd, 3. 55 LSD

 

[Michael Hughes]

They should have put a sticker under the hood on the cross member in front of the radiator.

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1999 2500 ST LB 4X4 Metallic Red, 5-speed, 3. 54 gears, LSD, camper and tow package
Westach Boost/EGT (pre and post turbo) mounted on A pillar.

 

[superdave]

i found a sticker under the hood... it says: PCM 56040199AC and ECM 3237303055... . change authoruty 8/11/99 dealer code 44075 date 3/15/2000... ... i was led to believe the cummins was epa approved as it came from the factory... so why the changes?????? it makes me really very unhappy with the truck.

 

[MikeR]

In your post of the sticker,it says the TSB# is 18-11-99. This update is not an emissions update,it was made for owners that were complaining of low power while towing. There were so many owners that complained of a mileage decrease after the reflash... likewise,there were owners that liked it. My '99 definitely woke up after the reflash. It was smooth all the way to redline where it had a hesitation at 2000rpm before the reflash. The tech told me it changes engine timing slightly.

Give it some miles to see if it gets better. Technicians have posted here before that the program doesn't always load entirely. If it doesn't,you can always have it re-done.

-Mike

[This message has been edited by MikeR (edited 06-01-2001). ]

 

[superdave]

thanks mike... the dealer is the one who told me it was an emissions thing... . i did not get any more power just much less mpg... since most of my driving is empty mpg means something to me... also i have no power when i am towing even a light load if my rpm is under 2100..... at or above 2100 it pulls terrific,,,,BUT 2100 gives me 75mph, above the posted limit... is 2100rpm when the turbo is working? i really know nothing as you can see... . i have put 20000 miles since the upgrade computer thing... it dont get no better as they say... thanks

 

[Bob Wagner]

Dave, Please go open your hood find the sticker that the dealer applied and please post the TSB number that is on the sticker.

Thanks

 

[Vaman]

I had the emissions update done and saw a loss of power and decreased mileage. I specifically told them I didn't want it done (I asked for the PCM update for safety reasons) but they "mistakenly" did it and couldn't reverse it. Just one of many, many reasons why I love the Dodge boys...

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98. 5 2500, 24v, 5 speed, QC, 4x4, 4. 10 LSD, short bed, Line-X liner, tow package, camper suspension, Westin nerfs, camper shell, TST PowerMax Competition, 275 RVs, Psychotty air, HX-40, 4" straight pipe exhaust, Southbend clutch, ProComp A/T 305/70/R16s, EGT/Boost/Fuel pressure pillar gauges, Grover air horns... Love my Cummins, no love for Dodge

 

[superdave]

rob the numbers under the hood are as follows... . PCM 56040199AC and ECM 3237303055 change authority 8-11-99 dealer code 44075 date 3-15-2000