P0551... duh duh duh

zhneon · Post by **zhneon** » Fri Jan 08, 2010 5:54 pm

*Clears throat*
Ok, so long story short, I had a major issue with a flat tire. Unrelated, but it brings me to my beloved mechanic, we'll call him mr. mech. So, I says, "Mr. Mech, I need you to replace the tire(s), and check out this CEL. Thank you." My CEL is P0551, if I recall this deals with power steering. I get the car back today, with good new all-season yokohamas on the front. Excellent. To my surprise, mr. M has ripped up my interior lighting (dash leds). He claims that these were "short cirucuiting" the computer, hence the CEL. :bs2:

Drive two miles, CEL is back on. So my question is, first, can anyone give me alternate information on P o551. PS fluid acceptable levels, no symptoms, 03 sxt. And also, could these lights in fact short circuit and cause this specific CEL. If so, it waited three months to do so.

I thought that this would be an appropriate sectiond because it is a ps CEL, but feel free to move it anywhere. Yes, it is a long story, but I trust my fellow 2gners to help. Thanks all.

OB · Post by OB » Fri Jan 08, 2010 6:16 pm

A quick search on the code reveals that P0551 is a fault related to the PS pressure switch. This switches job is simple; when PS pump load is high (i.e. parking a low speeds) a signal is sent to the PCM. The PCM then signals an increase in idle speed via the IAC and additional fuel. The idea is to prevent to engine from dying from excess load, same as when the AC is turned on. The switch is probably bad, causing readings that the PCM knows to be out of normal parameters, thus throwing a CEL.

Now, to answer your question, no, LED cluster bulbs cannot cause a CEL. The PCM does not monitor light bulbs or light circuits. A short in a bulb, LED or not, will 99% of the time simply cause the filament (or diode) to burn out, opening the circuit. The bulb is usually the weak link in a low-power lighting circuit, so fuses aren't needed.

Sounds to me like your "mechanic" is full of shit and should be replaced immediately. I recommend running any issues you might be having by us here at 2gn first in the future, you'll probably fare better.

zhneon · Post by **zhneon** » Fri Jan 08, 2010 6:24 pm

Thank you very much. As for the mechanic, I agree. Now, of course, I need to go in and rewire the lights which is a PITA. As for advice, 2gn is my first choice, and I checked the CEL here originally, but since I had two issues I thought it would be easiest to leave a ps issue to the "pros". So much for that idea.

Post by **occasional demons** » Fri Jan 08, 2010 7:22 pm

If Mr. Mech works for a garage, then I would go to the manager, and have $ taken off the bill, or make Mr. Mech put it back to the way it was. A little rubbing his face in it may help him out. You were charged for the labor of him destroying part of your car, so it is only right if the place compensates you for damages done. The PS switch is about $36, and it is in a fun spot to reach. If you are not careful, it can be cross threaded. A bit of fluid will leak out. being an '03 it is likely ATF +4.

zhneon · Post by **zhneon** » Fri Jan 08, 2010 7:27 pm

Unfortuneately Mr. Mech owns the shop, or I would have immediately said something. Oh, that and he is a good friend of my father's, which is a fail...
Thanks for the tip. I beleive that I was reading a thread about this a while ago. Is adding PS fluid the one that is detrimental? or is it adding ATF to ps... can't remember. I will prob have to just go get ATF.

Post by **occasional demons** » Fri Jan 08, 2010 7:40 pm

Using dad's friend FTL!

There was another member that had problems with that.

ATF is what you want. They switched to it in '02 or '03. If you are fast enough, it won't drain much, but rushing it could cause the threads to get crossed. I just took my time to make sure it threaded fully by hand, then tightened. It is in the PS rack on the rear where the input shaft goes in. the crossmember is a fine obstruction. If you don't feel comfortable with doing it, it would be cheaper to pay a regular shop than replace the PS rack for screwed threads.

OB · Post by OB » Fri Jan 08, 2010 7:44 pm

ATF+4 is the correct fluid. Use a 7/8" deep well socket to remove and install the switch. Top the fluid level off, run the engine, and turn the wheel from lock to lock several times to bleed air out of the system.

If that guys owns the shop, I feel bad for anyone who goes there. Sounds like he's one of those old school guys who is scared of new technology (i.e. computer controlled cars, LEDs, etc). I know guys who have been wrenching for 30 years who won't touch anything new. It's sad, but mechanics of yesteryear are no match for modern day technicians.

Post by **occasional demons** » Sat Jan 09, 2010 8:41 am

OB wrote: It's sad, but mechanics of yesteryear are no match for modern day technicians.

Well the ones that aren't open minded, or too stubborn to at minimum open a book and learn.

If anyone in just about any field doesn't know how to use the internet, I wouldn't trust them to be of the best of their abilities. There is prolly more current info there than in books. And like some books, you also have to be savvy enough to weed out the false info.

Yes, there are a few that can get by on the shear ability to figure it out as they go, but those are few and far between.

This guy is either being a total dick, because he doesn't think these "kids" should be adding unneeded stuff to the car, or he is just that dumb.

I may not agree with what ppl do with thier cars all the time, but I wouldn't try to blame something unrelated on it. If it did cause the problem, I would at least try to understand why it is a problem, and offer a soulution. At least it would show the customer that you are trying to help them keep the car the way they like it. A happy customer comes back with freinds.

zhneon · Post by **zhneon** » Sat Jan 09, 2010 10:08 am

Unfortunately my impression was that he truly thought that the lights were the problem. In the past I have also had a few issues, for one I was told that the codes I pulled via keydance "aren't accurate." To clarify he isn't a dick or anything at all, I think that he just seriously doubts that an 18 year old kid would know anything. Its not like I wired the lights up personally.

BTW I hopefully will get to the switch sunay. I appreciate all the help

Mopar00Neon · Post by **Mopar00Neon** » Sat Jan 09, 2010 2:25 pm

Ah, memories. When I was 18, I was a used car tech at a Ford dealer. Which means I worked on everything with at least 4 wheels that people might have traded in, or that was bought at auction.

Had a manager that doubted my abilities. I would have saved that dealer a lot of money over the years if he had listened to my write-ups on parts/service required.

Red04SxtLuvr · Post by **Red04SxtLuvr** » Sun Jan 10, 2010 11:58 am

zhneon, what a PITA. "old school" mechanics are fine for older cars, but usually not that dependable on new cars. They learn on older cars without all the computerized stuff and try to "fix" everything the same way. You probably know more about your car than Mr Mech. Sorry to hear about what a mess a simple problem became. Good luck with the switch.

zhneon · Post by **zhneon** » Thu Jan 14, 2010 9:00 pm

Never got to this on sunday lol.
Can anyone give me a pn for the pressure switch. Or perhaps which pn category to put a request in. I went to advance auto parts and explained exactly what I needed. And I got some part for $150.

Post by **occasional demons** » Thu Jan 14, 2010 11:00 pm

viewtopic.php?t=23634

Edit:
AutoZone PN: PS399

zhneon · Post by **zhneon** » Fri Jan 15, 2010 9:28 pm

why thank you