My intimate familiarity with N14's payed off today... '99 Freighliner died on the freeway at Sunset. He coasted to Iowa street and came to a stop here. Nothing like working right in the middle of the road!
While Insite locked itself up and froze the computer I checked all the usual suspects. ECM fuses at the battery, cranking voltage (11.5 okay there), fuel in the tank, coolant etc... Once it decided it wanted to talk I found DTC 0254 ECM turns off fuel valve supply voltages. Interesting.
According to the troubleshooting an ECM draw of over 2 amps or measured voltage below 6 volts at pin 16 (Fuel shut off solenoid) will set the code. Found the ECM ground fuse blown. Replaced but the code stayed active and Insite will not allow you to clear engine shut down codes. The ECM has to detect that the problem is fixed but since it has shut off feed to the solenoid how do I tell it to reset? Hmm, jumper wire from the starter to the solenoid post for just a second and the code resets and goes inactive. Truck starts right up.
Why would the ECM draw over 2 amps I wonder? I bet if the solenoid was failing... Passed the ohms test but man it's hot if you put your hand on it. Checked it again 0.0 ohms. Yeah, that's not right. Went back to the shop and got a new solenoid. Checked the old again before taking it off and it's at 1.8 ohms (Spec is 6-12 if I remember correctly). Change it out and check it again just because and it's over 13 ohms. Truck starts up, no faults, no leaks, ice is on it's way to Concrete again. Solenoid was heating up and the current draw went up with it. ECM says woah wait a minute and shut's off power to the solenoid.
Fascinating thing is this truck had a new ECM and harness put in a year ago. I wonder if they were having trouble?