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+--- Thread: ISX12 500EV bad de-mandated club (/showthread.php?tid=10136)
ISX12 500EV bad de-mandated club - thewondershowzen - 05-19-2025
Hello and thanks for letting me join. I am working on a firetruck that has an ISX12 in it that has been de-mandated and now has more trouble than before.
When this truck came in our shop to troubleshoot a CEL, it only had codes for a bad def head and the department decided they wanted everything removed since it wasn't the first time it had happened.
(We do not remove anything in our shop, but have sent people to this local business before with great luck) Now the truck is not correct and I am obligated to get them taken care of since I recommended this shop that has said they have done everything they can and that the truck needs to go to the stealership to diagnose a bad wiring harness. (rolls eyes)
After a local sh*p de-mandated it, (gutted both cans, and plugged the EGR) they could not get it to make enough power to pull 3rd gear for a week. (red flag, I know but) After them reflashing, reflashing, and reflashing, the truck seemed to run with decent power. But...
It will backfire through the exhaust about 30 seconds after being turned off almost every time the truck is drove. They took the truck back to troubleshoot and said that everything checks out on their end.
It has excessive white smoke on startup and a haze when running. The jake brake does not function, and the check engine light will come on with a soft code set in the transmission for engine overspeed when the RPM's exceed 1000-2000 RPM (not always consistent at what rpm, but will never go over 2000 without setting). P0726
The check engine light goes off after every ignition cycle, but comes on as soon as it is driven.
I have since checked every plug on the engine and transmission harness for bad or corroded connections and changed the engine speed sensor just because, all with no change.
I really feel they got a bad tune and would love a second opinion.
RE: ISX12 500EV bad de-mandated club - hhow55 - 05-19-2025
In regards to the backfire issue. Other's in the past have stated that issue was caused by a plugged EGR cooler.
RE: ISX12 500EV bad de-mandated club - thewondershowzen - 05-20-2025
(05-19-2025 )hhow55 Wrote: In regards to the backfire issue. Other's in the past have stated that issue was caused by a plugged EGR cooler.
Did they remove the egr to remedy the backfire?
RE: ISX12 500EV bad de-mandated club - hhow55 - 05-20-2025
Remove the egr then cleanout soot, and reinstall.
RE: ISX12 500EV bad de-mandated club - Rawze - 05-20-2025
also assume the de-mandate programming is bad. More then 90% of every file look at each year are.. half of which driver swears nothing it wrong while its blowing head gaskets and tearing up the engine internally.
copy the program out of the ecm and e-mail it to me for a proper review of what someone did in there.
info: https://rawze.com/forums/showthread.php?tid=8425&pid=72945#pid72945
RE: ISX12 500EV bad de-mandated club - thewondershowzen - 05-20-2025
(05-20-2025 )Rawze Wrote: also assume the de-mandate programming is bad. More then 90% of every file look at each year are.. half of which driver swears nothing it wrong while its blowing head gaskets and tearing up the engine internally.
copy the program out of the ecm and e-mail it to me for a proper review of what someone did in there.
info: https://rawze.com/forums/showthread.php?tid=8425&pid=72945#pid72945
I will get that copied today. Thank you
RE: ISX12 500EV bad de-mandated club - thewondershowzen - 05-21-2025
(05-20-2025 )Rawze Wrote: also assume the de-mandate programming is bad. More then 90% of every file look at each year are.. half of which driver swears nothing it wrong while its blowing head gaskets and tearing up the engine internally.
copy the program out of the ecm and e-mail it to me for a proper review of what someone did in there.
info: https://rawze.com/forums/showthread.php?tid=8425&pid=72945#pid72945
I will get that copied today. Thank you
RE: ISX12 500EV bad de-mandated club - thewondershowzen - 05-21-2025
Pm and ecm file sent. Thank you
RE: ISX12 500EV bad de-mandated club - Rawze - Yesterday
this file is soo badly done that it is a wonder that the engine does not go into derate and shut down. It is absolutely horrible and incomplete.
someone absolutely had no clue what they were attempting there, and it is very clear that they were doing nothing but poking in the dark with it, throwing random settings at it in hopes that something would stick. The result is trash however, and harmful to the engine in may ways, unfortunately. If whoever attempted this wants to actually learn how these engines and their programming works, they should get on my mumble server to start learning all this stuffs. Otherwise, everything they touch is going to be an absolute disaster.
.
Whoever made this mess also must have used the Winols software, as the file is also corrupted beyond repair. Third-party garbage software such as that is notorious for corrupting engine files so badly, and in this manner.
The engine will have to be flashed back to its factory programming and the de-mandate made from scratch again for it too be fixed and the program corruption removed.
The ECM needs to be updated/flashed with the latest factory software first before continuing.
** Back up all vehicle settings (in insite: work order + ecm template + ecm image).
** flash to latest factory software according to the engine ser#.
** run engine for 10 minutes on new factory software to rebuild data.
** copy it out via CT and e-mail it to me to have it re-done properly.
My opinions about a firetruck, ambulance, etc. ...
== THIS IS A PIECE OF EMERGENCY EQUIPMENT!!!!>>>>>>> PEOPLE'S LIVES DIRECTLY DEPEND ON EQUIPMENT SUCH AS THIS!!!!!.
NO ONE, BUT NO ONE SHOULD BE HALF-ARSSING SOMETHING LIKE THIS!!!.. IT HAS TO BE AS CORRECT AS ABSOLUTELY POSSIBLE!!!. --- THERE ARE NO EXCUSES!. THERE ARE NO SECOND CHANCES IF SOMEONE DIES OR SOME MAJOR PROPERTY DAMAGE OCCURS DUE TO GUESS-WORK, HALF-ARSSED ENGINE TUNING TRASH!!!.
ITS NO LESS THAN SOMEONE DOING A TYPICAL HALF-ARSSED DE-MANDATE ON A PASSENGER JET.. AND THEN BLAMING THE ENGINES AS IT FALLS OUT OF THE SKY AND KILLS EVERYONE ON BOARD DUE TO IT EATING ITSELF TO PIECES AS A RESULT!!!.
WELCOME TO THE BAD DELETE CLUB!