On the way to Death Valley last week, while towing the 5'er, the check engine light came on. (2005 F-350 w/ manual tranny). The manual says if the light is flashing, it's BAD. Thankfully, t wasn't; it was just on solid. The manual says there "could" be water in the fuel, or the gas (diesel?) cap "could" be lose. The light's supposed to go off after 3 cold starts. Well, the cap was on tight, and I'd last bought fuel where I always do at a heavilly-used Shell station, so I'm not sure about the water-in-the-fuel theory. The light did go off after 3 or 4 cold starts, and probably a tank and a half after it first came on. But then... a day later when we were out on a 4x4 trail in the middle of nowhere in Death Valley with no cell phone service, I turned the truck off so we could take in the views at the summit of the trail... and the darn thing wouldn't start again!! Well, it did start, but not the first, or the second, or even the 3rd try. On the 4th try I tapped the pedal and it finally turned over, but the dang check engine light was back on again - urgh! The next time I turned it off and on again, the light was out, and it hasn't been back on since. We made the trip home uneventfully (thank goodness!)
My questions: If I wait another 4-6 weeks (until I'm due to take it in for an oil change) to get the OBD codes checked out, will that be a problem?? What does that light REALLY mean??
Here's the rig parked when it wouldn't start again! It was very windy & the sun's in my eyes - ha!:
If it doesnt give you any more starting problems and the light stays off, I would just get them to read the codes when you go in for next service. Keep an eye on all gauges especially oil pressure and temperature. Anything else goes wrong I would take it in.
Has the HFCM been drained recently? You might also check the fuel filters to be sure they aren't dirty. Whatever it is, it sounds intermittent and can probably wait a few weeks. Of course, it won't hurt anything to change the oil early, either.
My only concern with waiting while the light is off, is that the codes may not be there to view if you wait too long. Maybe just running it in for a diagnostic hookup would be a prudent decision. I unhooked the egr valve in my 06 for a few days, and the check engine light came on. It went off a few starts after I hooked it back up. Service appoinment a few weeks later showed no codes. Maybe this isn't the norm, but it is what experience I have to share!
Well here we are a month and a half later, and I never did take it to the shop, and on our way back from Pismo this weekend the light came on again. I was towing again, and just getting up to speed before shifting into 4th gear at about 55 mph, and it lit up. Then, later on after we got home, it wouldn't start up again until I tapped the accelerator pedal. Three starts later it went out and it hasn't been back on in the last couple days. Hubby thinks the fuel pump has been making a weird noise lately, too, for whatever that's worth. Anyway... I'm taking it in to the dealer in the morning. Stay tuned!
The check engine light is telling you that the onboard computer has found a problem. When you are driving the computer is watching all of the sensors, inputs, and other parts of the engine, transmission, ABS, and body systems. If one of these systems is out of line it will set a problem code in its memory and turn on the dash light. This can be something as simple as a fuel cap that is loose or as major as a cylinder that is not firing. The diagnostic system is quite advanced, say when you start it sees a coolant temperature of X degrees, if in a certain amount of time the temperature does not rise then it knows that there is a problem with the sensor and reports the problem. Any dealer can pull the problem code, or you can also take it to AutoZone and they will pull the code for free.
Now my guess is a problem with the drive by wire system. The truck does not have a mechanical cable going to the engine. It uses a sensor on the throttle peddle to tell the computer how much power you are wanting. When you try to start the engine if it sees anything other than the normal position of the peddle it will not start and set a code. If there is a loose wire or other problem with the sensor it will see that problem and not start the engine. When you tap it you may be wiggling the wire and it then gets a good connection.
The paperwork says: "Faulty fan clutch and IDM 0.00 system performance tests 6.0 diesel, codes P0528, P0264, P0267, P0270, P0273. P0276, P0282, P0460 & P0611 (HOLY COW that's a lot of codes!) in memory. Perform KOEO test - pass; KOER test - pass. No hard codes. Pin point tests, test fan clutch failed, fan clutch not engaging, contact hot line #102477710, inspect wire harness - checks ok, R&R faulty fan clutch, and FICM (Fuel Injector Control Module) as per hot line, clear codes, retest system pass."
They said good thing I brought it in today 'cause I was only 600 miles away from the 36,000-mi warranty being up. I didn't have to pay for anything.
When I picked it up and left the shop, I could hear the fan reving up with the engine RPMs, but it went away after the truck warmed up. I've NEVER heard that before in the two years I've owned this rig - hmmmm...