Check engine light

[professor229]

Briefly.... check engine light on a 2004 Ranger... O'Reilly's report said it was the sending unit electrical signal that was wrong. Bought a lifetime guaranteed fuel pump/sending unit from A1. Removed bed, replaced the unit. To do this you have to disconnect the fuel pump relay, run the motor out of gas, then disconnect the battery. I did, fairly easy install, screwed up the relay so bought a new one, everything is fine. Took the grandkids fishing yesterday and on the way home, the check engine light came on..... I would bet it is the same problem.... Read some forums that said the error code light may still come back on after the fix and stay on until it recycles several times.... True? and.. If I take it to my mechanic who I usually hire but did this one myself, can he shut off the light and clear the error code for good? or should I just try the cycle it several times and be patient?

 

[franklin2]

What is the exact error code or codes they received?

 

[professor229]

PO 462 Fuel level senser 'A' electrifcal circuit input signal had low voltage for a predetermined period of time....

The above from the OReilly VeriScan report... Showed it to my mechanic and in genreral terms, the sending unit was screwed up... and of course, it is part of the entire fuel pump assembly... so changed it all....

 

[mperry]

Ah, that odd little P0462. I might just buy a cheap scan tool and reset it myself. Alternatively, getting a scan tool ap for your phone and bluetooth connector. That'd set you back around $150 but you can use that to scan for problems. I thought the normal way to get to the pump is to drop the tank, but you removed the bed? The hose on my '94's tank started leaking and it was $500 to drop the tank, so doing it yourself was a good step. I paid rather than drain the tank at home.

As you said, the PCM is receiving an out-of-spec reading. You might also see the fuel gauge show odd readings. You might try testing your old fuel sensor's readings with an ohm meter and compare it to your new one. On the old one, connect the multi-meter to the wiring and move the float from empty to full. If it was still good the Ohm readings should vary smoothly. A fluctuation (dead spot?) indicates it was bad. Ford published the readings at one time (low and high readings) but I couldn't locate them. It can also be a wiring problem. Damaged wires or corrosion in one of the connectors can trigger the same error. In the past I've had 2 problems with new parts from O'Reilleys so that's another possibility. In my case, that's about a high fail rate.

Sorry if my info is out of date. It's been decades since I last had a sensor fail... pre OBDII.

Oh, and maybe reset? One person says he disconnected the battery, waited a couple minutes, and reconnected. Another said "To reset the fuel gauge on the Ford Ranger you need to hit the ODO/TRIP button, then turn the vehicle off. Hold the button and turn it back on and make sure it says it is in ODO/TRIP mode. Now turn the vehicel off again. Wait 10 min, turn it on, then turn it off. It is now reset."

 

[professor229]

Hey.. thanks for the suggestions.... and I got a good idea... I forgot that my son already has a "reader" but I just texted him to ask if it would also clear the code..... Will find out about that.. I know that O'Reilly's at one time, had a code reader and it WOULD clear the code but they could not do it... sooooooo they would get to that screen and I had to press the enter key to do that function... but this is a new system they have and it is imprressive but when I took the reader out to the Ranger and plugged it in and read it, there wasn't a menu option that I remember... doesn't mean that there isn't a menu that has an option to clear the code... so.... I would need to take it back and might.... However, there are several articles that I read that said that this Ranger computer may take "several cycles" before it would clear the code... I have only run the truck twice since then so I am going to start driving it back and forth a few miles to the lake each day and see if it clears itself... I do have a mechanic that I checked with (he is busy) and he agreed that the sending unit was probably to blame. I think if I take the Ranger down to him, he would clear the code for me too... but I will try to drive it a bit first... The weird thing is that when the problem light lit up, the gas gauge still read correctly and the fuel pump still worked properly too.... so ??? I did NOT buy the fuel pump at O'Reillys..... I got a lifetime warrantied fuel pump from A1 auto.... and a back story.... When I bought this Ranger it was a project... and I have over 200 hours into body and mechanical work tied up in it... It looks pretty nice.... and only has 108,000 miles on it. I paid $500 for it... It was totaled from body damage when it went into a ditch and the box had a major dent... I had fun pulling it... and eventually did with a ..... well... toilet bowl plunger... not kidding... but decided to get a used box from Texas and did for a very reasonable price... no rust... and I repainted it and installed it... It is easier to remove the bed of an older Ranger (six bolts and three on the gas tank filler tube and one electrical connector separated) than it is to drop the tank... You also do NOT have to remove the box... I slid it back two feet by myself, you know, one side, and then the other, repeat.... until the top of the gas tank is sitting right there looking at you... it was so easy... I am going to drive it a few times now to see if the light does go off by itself as suggested by several other sources.... I will try to clear the code myself with my son's machine or take the Ranger down to my mechanic and buy him a six pack... I know you can shut off the engine light by removing the battery cables and that had to be done to install this new fuel pump/sender.... but I am pretty that it does NOT clear the code... If all else fails, my mechanic will get it to figure it out.... but that is down the road a bit..... by the way.... estimates on this project was around $500 in MN and flat rate in California was $1200.... unreal... I have a whole $100 into it.. thanks again...

 

[ericbphoto]

OBDII reader with Bluetooth is less than $50, more like $20. App for your phone is free, such as Torque Lite

 

[professor229]

OBDII reader with Bluetooth is less than $50, more like $20. App for your phone is free, such as Torque Lite

I know my son has one and yes, blue tooth so he reads the info from his phone... my question to him is if his will clear the code.... and I will find out that when he replies.... Other than that, the OReilly's system is as advertised on TV... take it out, turn on the ignition, plug it in, wait until it tells you "done... take it back in to the store" where the kid at the counter plugs it into their interface/system and prints out an impressive sheet with all you need to know... of course, trying to sell you the solution parts ..... but this kid didn't really care one bit if I bought a fuel pump from them or not..... and they were two/three times higher than A1...

 

[professor229]

So..... replaced the fuel pump/sending unit assembly. My son used his check engine line tool to clear the code.... drove it down to the lake today (five miles) and no light came on. Started the Ranger to come home... and there it was "check engine light." I feared it was not really the fuel pump/sending unit because it was less than three years old... but changed it anyway.... Now, it is apparent, that this was NOT the problem... Next step? I will crawl under so I can see the wires that run from the plug on top of the gas tank and see if that harness/wiring runs into the cab or under the cab to the engine compartment... and see if there is a ground wire that is bad or a frayed wire.... The gas gauge and fuel pump I installed work fine and correctly. Ordinarily I would just forget about it.... but this one is an annoying problem... and I would like to know... Anybody else got any other ideas about what I should be checking? Thanks.