Why can't my dealer flash my ECM?

[GWS]

Searching on Fritz's site I found TSB 21-04-00, which describes exactly the problem I am having with my shifts, since increasing the line pressure, and adding a 200 ohm resistor to the governor circuit. I thought having the dealer flash the ecm to reprogram it according to the TSB would be a simple and quick procedure. WRONG! After waiting for 2 hours, I popped into the garage to see what the problem was. They said they couldn't get the scanner to ID my ECM, and furthermore, the scanner could not acknowledge the existence of my PCM. I had my PE hooked up at the time. Does anyone know if the PE wiring will interfere with this process? Any other ideas? The dealer is stumped. After wasting two and a half hours I took the truck home.

 

[Dane]

Yes, the PE box could cause problems. All the various "black boxes" function by intercepting commands and data from the various computers (Dodge, Cummins) and sensors, etc... The black box alters the commands and data and then resends it back onto whatever buss or device it was intended for in the first place. In effect it tells lies #ad
to the different devices to cause the engine to get more fuel, boost, timing or whatever. These same "lies" could be going back to the computer that the tech hooked up, causing it to not be able to ID the ECM it's trying to program. I would also worry the program that's supposed to be written into the system might not get there properly due to the black box being hooked up.

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2001 HO 6 speed Regular Cab SLT 4x4 3. 54 anti spin 2500. Used for the daily grind and sneaking away to some secret Baja beaches toting a cabover

 

[JR2]

I have to disagree... if you have a PE the only two places that it hooks to the truck are on the injection pump and the map sensor. I have a hard time believing that plugging into the data port in the cab is effected by cliping the voltage on the boost sensor. Now if you have an PE EZ I could see how there might be some problems as it connects to a data port and is in direct communications with the ecm. Just my opnion, I could be wrong.

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John D. Rathert Jr.
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01 2500 Forrest Green Sport SLT+ QC LWB 4x4 Auto 3. 54 rear end with all options avail. DC Nerf Bars, DC Grill Guard, DC mud flaps, Line-X bed liner, Leer 160XL Topper, Power Edge, EZ Edge, SPA Boost/EGT Gauge on pillar mount, DDT's tc/vb combo, 275 RV injectors, DD 4" Exhaust and a KN RE0880 where the air box use to be. New turbo (HX40), SS fuel lines and bigger injectors in planning stages... . See My Truck, Dads truck: 98. 5 3500 SLT QC LWB 4x4, Brother Truck: 92 W250 SLT CC LWB 4x4 (Dads old truck) Winter fun - 2000 Skidoo Summit 700
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[Dodge-Tech]

JR2 is right. The ECM and PCM are not interfaced with your box. The injection pump tap is hooked up after the electronics, so they can't see the out of limit parameters and set a code. The dealer's DRB III (scan tool) probably needs an update program. There have been many situations at dealers with software problems with their scanners. If I were you, i'd wait a few weeks and have them try again, or try another dealer.

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98. 5 Intense Blue, 24 valve clubcab custom dual exhaust w/5" tips, Autometer pyro & boost gauges, K&N filter, 4. 5" Skyjacker lift kit, 36"x14. 50. 50"x16. 5" Mickey Thompson baja belteds, PE-EZ, 275 injectors, no turbo silencer ring, Mopar Performance Trans Pan.

 

[Dane]

Thanks for the info! Can you explain how the box works only being hooked up to the pump and MAP sensor?

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2001 HO 6 speed Regular Cab SLT 4x4 3. 54 anti spin 2500. Used for the daily grind and sneaking away to some secret Baja beaches toting a cabover

 

[Dodge-Tech]

The box works by monitoring boost pressure via the map sensor. Map stand for "manifold absolute pressure". It then changes the pulsewidth signal at the injection pump to tell it to add more fuel. This is done after the pump electronics to prevent an out of range condition.