• Mustang Forums
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
  • Fox 5.0 Mustang Tech

Help with scanner codes

  • Thread starter Thread starter subcreep
  • Start date Start date Mar 23, 2004

subcreep

New Member
Dec 1, 2003
30
0
0
Jax, FL
Mar 23, 2004
#1
  • Mar 23, 2004
  • #1
I ran the KOEO (key on engine off) test and got no hard faults, but I did get a 31 (EGR Valve position sensor) error from memory.

For the KOEN (key on engine on) test I got a 44 (problems in thermactor air system) and a 94 (Thermactor air system problem in right bank)

Are these codes related, if not what should I do to troubleshoot? My check engine light only flashes when the outside air temp is below 55 degrees. The car runs really rich, I smell gas constantly even when idling and I get terrible gas mileage. I've checked for fuel leaks (there are none), and the EGR valve vacuum is good.


'92 vert LX - BBK cold-air, o/r x-pipes, 3 chamber flows
 

subcreep

New Member
Dec 1, 2003
30
0
0
Jax, FL
Mar 23, 2004
#2
  • Mar 23, 2004
  • #2
Just to add to this problem, there were no hard faults during either test. So what the hell is the thermactor air system? It looks like the vacuum system???????
 

jrichker

StangNet's favorite TOOL
In Remembrance. Thank you for your contributions
Mar 10, 2000
27,512
2,813
234
Dublin GA
Mar 23, 2004
#3
  • Mar 23, 2004
  • #3
Codes 94 & 44 - Check vacuum lines for leaks, & cracks. Disconnect the big hose from smog pump: with the engine running you should feel air output. Reconnect the smog pump hose & apply vacuum to the first vacuum controlled valve: Its purpose is to either dump the pump's output to the atmosphere or pass it to the next valve. The next vacuum controlled valve directs the air to either the cylinder heads when the engine is cold or to the catalytic converter when the engine is warm. Disconnect the big hoses from the back side of the vacuum controlled valve and start the engine. Apply vacuum to the valve and see if the airflow changes from one hose to the next.
The two electrical controlled vacuum valves mounted on the rear of the passenger side wheelwell turn the vacuum on & off under computer control. Check to see that both valves have +12 volts on the red wire. Then ground the white/red wire and the first solenoid should open and pass vacuum. Do the same thing to the light green/black wire on the second solenoid and it should open and pass vacuum.

Remember that the computer does not source any power, but provides the ground necessary to complete the circuit. That means one side of the circuit will always be hot, and the other side will go to ground or below 1 volt as the computer switches on that circuit.

See the following website for some help from Tmoss (diagram designer) & Stang&2Birds (website host)

http://www.veryuseful.com/mustang/tech/engine/images/fuel-alt-links-ign-ac.gif

http://www.veryuseful.com/mustang/tech/engine/images/88-91eecPinout.gif
 
You must log in or register to reply here.

Similar threads

Electrical Code 29 again
  • Creomod
  • Jul 31, 2026
  • Fox 5.0 Mustang Tech
Replies
7
Views
248
Fox 5.0 Mustang Tech Aug 3, 2026
Creomod
2
Running very very rich
  • 2esoteric
  • Oct 31, 2025
  • Fox 5.0 Mustang Tech
Replies
4
Views
390
Fox 5.0 Mustang Tech Oct 31, 2025
Noobz347
C
Engine Code 94 and 13
  • CmdrDerp
  • Nov 3, 2024
  • Fox 5.0 Mustang Tech
Replies
3
Views
377
Fox 5.0 Mustang Tech Nov 4, 2024
AeroCoupe
Engine Looking for suggestions and or ideas
  • PonyGTrider
  • Aug 25, 2026
  • Fox 5.0 Mustang Tech
Replies
17
Views
346
Fox 5.0 Mustang Tech Yesterday at 12:17 PM
PonyGTrider
J
Thanks for the information on codes 31,34,44 and 94!
  • JK86LX50
  • Mar 5, 2025
  • The Welcome Wagon
Replies
3
Views
313
The Welcome Wagon Aug 5, 2025
gkomo
Share:
Bluesky Email Share Link
  • Mustang Forums
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
  • Fox 5.0 Mustang Tech
Menu
Log in

Register

  • Forums
  • What's new
  • Media
  • Resources
  • Contact
  • Sponsor
X

Privacy & Transparency

We use cookies and similar technologies for the following purposes:

  • Personalized ads and content
  • Content measurement and audience insights

Do you accept cookies and these technologies?

X

Privacy & Transparency

We use cookies and similar technologies for the following purposes:

  • Personalized ads and content
  • Content measurement and audience insights

Do you accept cookies and these technologies?