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Code 538

  • Thread starter Thread starter wytstang
  • Start date Start date Nov 24, 2005
W

wytstang

Mustang Master
Mar 14, 2004
4,988
4
78
Summerville,SC missing South Fl. weather :(
Nov 24, 2005
#1
  • Nov 24, 2005
  • #1
I've had this little problem since my PIP stator went out a few weeks ago. And again it was triggered going a constant 70 mph on the highway. KOER showes codes 538: Insufficient RPM change during KOER dynamic response test/ Operator error. This is after I reved it to 5000+ rpms. The car on the highway didn't seem to have the get up and go power it used to have in 5th gear going 70mph. I was hoping after the entire dizzy was replaced with a mint condition used dizzy with a brand new PIP stator installed and cap and rotor too. But it still feels some what down on power, now I don't know if the o2 sensor (it showed up during a KOER test) is being triggered by the other problem (codes 538) or should I just replace the o2 sensor and see if that fixes both problems. I mentioned the code to the divability tech at ford who fixed my pip stator and worn dizzy. He said that codes was probably triggered due to the dizzy being worn out. He showed me my dizzy and it was very worn out, so he gave one he had and just replaced the pip. Low end feels great but top end feels slugish which the o2 could cause this. But the CEL only comes on at 70+ mph and around town (50mph) no CEL and runs perfect. The car has a new fuel filter, fuel pump(255), plugs, wires, cap and rotor, will be running seafoam through in the next week or so. Anyhelp with this code 538 is welcomed and with in the next month both o2 sensors will be replaced they are due. Unfortunatly my internet is somewhat fubared so getting on is somewhat difficult, but I will find a way to read any responses so please leave some if you can. *cough* JT/Grady*cough* :SNSign:
 

HISSIN50

"How long does it take to get help in here?
15 Year Member
Nov 29, 1999
31,179
33
129
Nov 24, 2005
#2
  • Nov 24, 2005
  • #2
Danny, Grady can help you a lot more than I can, but I will take a little stab at it.

The PIP code can be related to the O2, as you said. With one or more cylinders not firing as they should, it will funk the mixture and stoichiometry.

A reminder that at WOT, O2 input is fairly ignored for that time period. So I kinda doubt the O2 is causing a high RPM/demand lack of power. Does that sound good to you Danny?

I have a faint feeling that at high RPM, the PIP signal is being obscured or washed for some reason. The SN95 PIP uses data from notation of the rising and falling edge of its movement (Foxes only use one).

Do you note any missing at all, or is it like you hit the proverbial wall at high RPM? One other thought - how are the plug gaps?though a bit of a PITA, have you closed the gap a little to see if it helps?

Because of all the soaking issues you have had this season, I would also be a little concerned that one or more electrical connections has become corroded. During high frequency situations, these can rear their ugly head (loss of amplitude in sensory readings or diminished frequency).

My random thoughts. I bet others can help ya out a bunch. Good luck Danny.
 

HISSIN50

"How long does it take to get help in here?
15 Year Member
Nov 29, 1999
31,179
33
129
Nov 24, 2005
#3
  • Nov 24, 2005
  • #3
Oh yeah, for grins have you reset the KAM and observed what it does and what codes are generated?
 
W

wytstang

Mustang Master
Mar 14, 2004
4,988
4
78
Summerville,SC missing South Fl. weather :(
Nov 24, 2005
#4
  • Nov 24, 2005
  • #4
Well the diveability tech cleared all the codes so KAM is clear. There is no sign of a miss at higher RPMs so the lack of "passing power" I used to feel before the PIP started going south. At 70mph I have to drop it into 4th to get the "get up and go" feeling that I used to get from 5th (thanks to 3.73s). The o2 came up during normal KOER test the code 538 came up after the test was done and I gunned it to 5000 and it flashed that code, just like before I had the tech replace the pip. But because the car stays under 70mph for extended periods it never popped up again. As far as the "soaking" goes the water never reached passed the bottom of the door. The only reason it got inside the car was due to the seat bolts "seaping(sp)" through. Even then it didn't reach the PCM not evn the pcm ground (although I cleaned it just in cae). The bottom of the oil pan is as far as the h2o reached during the storm. I haven't closed the gap because they worked fine prior to the current issues that have occured (gap at .54 motorcraft). Thanks for your reponse JT you've been very helpful; much appreciated
 

mo_dingo

20+ Year Stangneter
Aug 26, 2003
3,031
2
58
Tucson, AZ
Nov 25, 2005
#5
  • Nov 25, 2005
  • #5
538 code means you did the self test wrong, i.e. you didn't cycle the brake or steering wheel or OD button during the test at the right time..Nothing to worry about.

That is all I have for you now.
Scott
 
W

wytstang

Mustang Master
Mar 14, 2004
4,988
4
78
Summerville,SC missing South Fl. weather :(
Nov 25, 2005
#6
  • Nov 25, 2005
  • #6
Really........so then it's just the o2 triggering the CEL on at a constant 70+mph??That's the only other code it spit out left bank reading lean. Could this cause the lack of "passing power" I'm experiencing(sp?). The CEL only comes on at high rpms/mph (constant) so I was thinking the o2 was out of the picture (closed loop). Damn Scott I feel a lot better.
 
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