I have two codes PO201 & PO221. I have replace #1 injector , #1 coil pack and throttle position sensor. My truck is still running rough and throwing the same codes . I drive a 2005 F150 4.6 liter. please help
Customer do you have access to a volt meter and the ability to use it?
yes; I am a fork lift technician but am lost on newer autos. thank you Richard
Richard, were these the same two codes you had when you first started trying to repair the truck? Also, the P221 - TP ciruit range/performance fault. Is only set during the run test. Do you have access to a scan tool that can read pid data in the engine computer?
The first things I would check would be fuses #5, #29, and #30 in the interior fuse box behind the passenger's lower kick panel. Then with the key off remove all three PCM connectors. Inspect the pins on the PCM and in the connectors for water intrusion, or pin damage. If you don't find anything, leave the PCM disconnected for five minutes. Reconnect everything an try to start the truck. See if your problem has cleared up.
I'm concerned that you possibly may have an engine computer problem. Try this first, if that does not clear your problem up, I will walk you through further pinpoint tests to try to isolate the cause of your problem.
Hope this helps,
Just to let you know, if you do need a PCM, the PCM is covered by an 8 year/80,000 mile emission warranty.
Michael, I checked all the fuses and they checked good , unpluged the connections on the PCM and restarted the truck. Same thing . I did not know the PCM had an 8 -80 warranty. what next. I do thank you for your time. Richard
Richard, although you have two different codes I am going to focus on just one for now. Let's focus on the P0201. That is the injector code, that is most likely why you have the engine skipping. With the key off and the battery disconnected, remove the connector on the PCM (engine computer) that is closest to the passenger's side of the vehicle. Find the tan wire in the connector. Now remove the middle connector and find the red wire. Check the resistance between those two wires. It should be between 11 and 18 ohms. Then check each of those two wire for a short to ground. If those checks are good then you most likely have a PCM failure. The only thing that could cause that code is if the injector resistance is off, there is a problem with those wires, or a bad PCM.
As far as the TP sensor is concerned, you may want to make sure it is connected properly to the throttle body. It is possible to install incorrectly. I'm more concerned about the injector code though. If the PCM is bad it could cause more than one problem.
All Ford's carry an 8yr/80k mile emissions warranty that covers the PCM and the catalytic converters.
Let me know what you find.
Hope this helps, if you have any further questions do not hesitate to ask.
Michael, I checked the resistance of those two wires and had 12.3 ohms . So I will assume the PCM is bad. You ask if I had access to a scan tool. When this started I bought the OBDCOM software and connector. I noticed last night when tring to read the TP sensor and RPM of my truck Ihad no readings at all. My guess would be the PCM is gone. Thanks you have been a life saver. Ineed to ask one other question, will ford dealers warranty the part if I replace it. Richard
Richard, unfortunately for Ford to warranty the part a Ford dealer has to complete the repairs. I'm sure that when you go in, the dealer will inform you that if the PCM is not the problem you will be responsible for all charges. But as long as what we have tested is correct I am confident that you have a PCM problem. The emissions warranty should cover all parts and labor costs for the PCM replacement.
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Ford Senior Master Tech & ASE Master w/14 yrs exp. Served on Ford's Tech Review Panel