jpete Posted April 4, 2011 Share Posted April 4, 2011 2004 F350, has a very intermittant cranks normally, wont start. Truck was towed to our shop. Engine cranked 10 seconds and would not start,was monitoring ICP which went to 1500psi imediately during this crank. Cranked it again for another 15-20 seconds, and suddenly started. No koeo or koer codes. Failed network test and showed U1262 during that test. Everything appears to be working. Never saw a code like this before. Had a hell of a time finding it on the PTS site. Ever come across this code before. Could it cause and intermittant cranks wont run? Quote Link to comment Share on other sites More sharing options...
Jim Warman Posted April 8, 2011 Share Posted April 8, 2011 A few words of caution about the network test and "U" codes. When performing a network test, if a particular module isn't installed on a unit, that module may be listed as a "fail" rather than a "module not present". The results of the network test need to be considered carefully to determine what it is really telling us. As an example, if we see "PAM (park aid module) - Fail network test" kind of message, the first thing we need to do is determine if the truck has a park aid module. You don't say what module(s) failed the network test making it a little difficult to offer too much help. That you are communicating with the truck and can read ICP_PRES, one would assume that the PCM is functioning and, in the abscence of any od demand FICM codes, that the FICM is also capable of responding to the network ping. Similarly, network codes can be a little worrisome. If a network code isn't repeatable or isn't accompanied by a symptom, I'm not too likely to spend much time on it. Comm codes ("U" codes) can be set simply because a module took a little long to boot up or a module momentarily sent out some "unexpected" information. ("Noise" on a sensor circuit, RFI, loose connection, that kind of stuff.) Your U1262 indicates a concern has been present with communications on the SCP network - you don't say that this is an Excursion (which would have PATS) so that leaves something to do with the instrument cluster - not too likely that this is going to be the cause of a no start. The "no codes" thing is a bit bothersome... not even a P1000? or a P0603? You'd expect "something" if it was one of the usual suspects. I'll caution against using ICP_PRES when looking for a no start/hard start cause. ICP pressure is a computed value... that is to say if the PCM doesn't like what the ICP sensor is telling it, the PCM will make up shit... and even display it back to you. ICP_V (ICP volts) is what you want and you need to see IPR% along with it for it to make any real sense. There are some other PIDs to monitor listed in section 4 of the PC/ED. If this is an early build '04, I'd begin by looking for ICP sensor bias KOEO - should be 0.18 to 0.24 volts - and/or an oil leak at the back of the motor... Good Luck. Before I forget... When looking in the online WSM for codes and such, there is a search box near the top of the window (right beside the printer icon) - you can enter your search term there (in the case U1262) and it will display the results in a popup window. Quote Link to comment Share on other sites More sharing options...
jpete Posted April 14, 2011 Author Share Posted April 14, 2011 Hey Jim, Appreciate the response. I'll remember the tip on the ICP monitoring. Out of ignorance and habit we always look and the PSI when we have a no start. We have chased our share of internal oil leaks. There was a P1000 code which I failed to mention. The network test is not something I have any experience with. I was kind of grabbing at straws. The IDS reported System: Network Test Fail No response on the UBP line pin 3 on the DLC Standard Equipment Modules U1262 HEC SCP Data Link Fault I was thinking even though it does not have PATS that some crazy conflict in a module could cause a cranks won't run? I could not repeat the problem, so I did not pursue the codes any further. I returned the vehicle to service and kept my fingers crossed. Not comfortable with not finding a problem cause I know a breakdown with occur at the worst time and I'll have another tow bill. Quote Link to comment Share on other sites More sharing options...
Jim Warman Posted April 15, 2011 Share Posted April 15, 2011 HEC is Hybrid Electronic Cluster (Instrument Cluster).. Since your code hasn't returned one can temporarily "assume" that it might be something transient or nuisance. Your P1000 isn't really a code in the truest sense. We generate those whenever we clear DTCs and they wont go away until all the continuous monitors run their course and deliver a "pass". When I see a P1000, I get snoopy and look at CLR_DIST (the mileage traveled since the code was cleared). There's a good write up on the diesel engine monitors in the PC/ED Section 1. Assuming this is an early build motor (ICP at the back under the turbo), I've seen a lot of funky ICP sensors. These can all manner of grief and do it intermittently. Do the biased sensor check (KOEO voltage) first - it's quick, easy and non-intrusive. You see the odd funky ICP sensor on late build engines but not with the regularity of an early build... If it does become a non start, there are several PIDs you can monitor that will get you looking at your problem area. These are listed in the PC/ED Section 4 under the "Hard start/no start" heading.Step 10a through step 10i pretty much cover anything that will keep the engine from starting (other than low compression concerns). HTH.... I am also assuming that you have access to the online manuals? Quote Link to comment Share on other sites More sharing options...
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