Attention: TDR Forum Junkies 
This post pertains to the Cab and Chassis 6. 7L engine only.
Last week I posted that with 24,000 miles on the odometer I had a Check Engine Light and a P0191 code. The code indicated the ECM detected an issue with the fuel rail pressure sensor. The local dealer advised me that a note from an engineer at Cummins stated that Cummins is aware of the problem and advised that in most cases, the fuel pressure sensor is not actually bad, the computer only thinks it is. The notice advised that a software update will be issued in October to correct the problem. Later I spoke to someone at Cummins and was told my symptom was different and I had a different problem.
I decided to take the truck back to my selling dealer who is 300 miles away because that dealer has a Level IV trained and certified Cummins tech. I hooked up my fifth wheel and left early Monday to go to Gainesville (TX) and spend a day or two having the truck examined and repaired if possible.
After I arrived in Gainesville and parked my trailer I was driving slowly down a local street and was amazed to glance down at the instrument panel and see that the Check Engine Light was gone.
The CEL and code had been on for a week and 3,000 towing miles and suddenly the light cleared itself.
The dealership took my truck in the following morning and checked it out and could find no cause for the CEL. I learned that the computers on the new engines are very sophisticated and are capable of monitoring many functions. The computer uses complicated and sophisticated programming that allows it to check and recheck these functions and after a programmed number of key cycles the computer can extinguish the code if it decides the original fault is no longer present.
The mysteries of computers!!! I guess I can still say my truck is troublefree after more than 25,000 miles.
Last week I posted that with 24,000 miles on the odometer I had a Check Engine Light and a P0191 code. The code indicated the ECM detected an issue with the fuel rail pressure sensor. The local dealer advised me that a note from an engineer at Cummins stated that Cummins is aware of the problem and advised that in most cases, the fuel pressure sensor is not actually bad, the computer only thinks it is. The notice advised that a software update will be issued in October to correct the problem. Later I spoke to someone at Cummins and was told my symptom was different and I had a different problem.
I decided to take the truck back to my selling dealer who is 300 miles away because that dealer has a Level IV trained and certified Cummins tech. I hooked up my fifth wheel and left early Monday to go to Gainesville (TX) and spend a day or two having the truck examined and repaired if possible.
After I arrived in Gainesville and parked my trailer I was driving slowly down a local street and was amazed to glance down at the instrument panel and see that the Check Engine Light was gone.
The CEL and code had been on for a week and 3,000 towing miles and suddenly the light cleared itself.
The dealership took my truck in the following morning and checked it out and could find no cause for the CEL. I learned that the computers on the new engines are very sophisticated and are capable of monitoring many functions. The computer uses complicated and sophisticated programming that allows it to check and recheck these functions and after a programmed number of key cycles the computer can extinguish the code if it decides the original fault is no longer present.
The mysteries of computers!!! I guess I can still say my truck is troublefree after more than 25,000 miles.
