U codes

2013 FORD FOCUS
200,000 MILES • 2.0L • 4 CYL • 4WD • AUTOMATIC
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CHYANNE SHERIFF
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I have u codes, uo101,u0121,u0131,u0140, and u0151... how long should a diagnostic test take to find the problem? the car is not having issues . transmission changes fine, starts fine, no noises and no other lights are on but the check engine light. is 2 to 3 hours normal for these codes.
Oct 6, 2020 at 9:58 PM
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STEVE W.
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Communication codes can be difficult to track down depending on what tools a shop has. Usually you need to scan all of the modules to determine which ones are online and if one or more isn't, then go to the one(s) not online and test to see if they are offline because of an internal problem or if it is the communication buss that is the issue. In this case there are multiple modules that have lost communication so it could be a power issue as well that is causing it. Over all I would say diagnostics would take 1-2 hours or so if the shop has to dig but it depends on how good they are with diagnostic work or if they farm out that work to someone else.
Oct 7, 2020 at 12:14 AM
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CHYANNE SHERIFF
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I know one of the codes says the car will not start with the code, but the car is starting fine and there is no problem with gear shift. another code says there should be .. should the car be showing some symptoms of the codes? what would be the worst thing it could be? Thank you
Oct 7, 2020 at 6:50 AM
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STEVE W.
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It depends on what type of code it is. These all should cause some symptoms if they are current codes. I would probably write them down, then clear them and see which ones return. They could be caused by a loose or faulty power feed or a module that is intermittent and that is what could take a while. Most of them will set if the communication is lost for more than a few seconds, so even a loose connection could do it.
Oct 7, 2020 at 7:15 AM
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CHYANNE SHERIFF
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Thank you, I will do that. how do i clear the codes? can i clear them with the obd2 on my car or will i need to get code reader and hook it up to the obd2 under the dash? i can access the codes from the steering wheel but i did not now if i could clear the codes that way. How do i now if they are current codes or old codes? Thank you
Oct 7, 2020 at 7:30 AM
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STEVE W.
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I use a scan tool to clear them as that way I'm sure they are gone, plus if they come right back I can quickly scan again to see if the issue causing them is now there. I don't think you can clear them without a scan tool as most on board systems let you see the codes but not erase them, that is to keep people from clearing a code prior to sale or inspection. Unless they changed it the on board system won't tell you if they are current or history codes, but at least one has to be current if the CEL is on as history codes generally turn off the light after a few drive cycles where they don't return.
Oct 7, 2020 at 8:47 AM
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CHYANNE SHERIFF
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The light did come on once before after i put in gas and the car tried to cut off at the pump.. the car has a capless gas tank and the car was running while i was pumping gas. two days later the light went on but three days later it went off. i was told to shut the car off when pumping gas and it should not happen again.. something about evaporation.
Oct 7, 2020 at 9:12 AM
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STEVE W.
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Yes, you want the engine off while filling as the system could decide to run an EVAP test and draw a lot of fuel vapor or raw fuel into the system and cause problems. Not just triggering the light but it could draw fuel into the EVAP canister or the lines. Replacing those because of the extra fuel in them isn't cheap.
Oct 7, 2020 at 10:16 AM