2nd Generation Specific (1986-1992) 1986-1992 Discussion including performance modifications and technical support sections.

Tricking the ECU (not MOP.. no solenoids + resistor = no CEL?)

Thread Tools
 
Search this Thread
 
Old Sep 25, 2004 | 10:35 PM
  #1  
poor_red_neck's Avatar
Thread Starter
Wait................What?
Tenured Member 10 Years
 
Joined: Apr 2003
Posts: 521
Likes: 0
From: Raleigh/Cary, NC - USA
Tricking the ECU (not MOP.. no solenoids + resistor = no CEL?)

For those who have removed emissions:

How did you get rid of the CEL?

Im tired of having to pull codes for the AWS, Relief, Switch, 6pi, etc etc everytime I need to pull ECU codes. That and now that the damn car is fixed... I'm tired of seeing the check engine light.

Will putting a resistor of the same ohm reading as the solenoid fix this?
Reply
Old Sep 25, 2004 | 10:36 PM
  #2  
poor_red_neck's Avatar
Thread Starter
Wait................What?
Tenured Member 10 Years
 
Joined: Apr 2003
Posts: 521
Likes: 0
From: Raleigh/Cary, NC - USA
btw i have searched.
Reply
Old Sep 25, 2004 | 11:50 PM
  #3  
WAYNE88N/A's Avatar
Lives on the Forum
Tenured Member 05 Years
 
Joined: Feb 2004
Posts: 5,721
Likes: 3
From: Coldspring TX
I don't know, but a solenoid acts VERY different than a resistor electrically...For instance, reading a solenoid out with a meter's puny power source might net you about 2 ohms (depending on the function and "power" of the solenoid, of course), but when the ECU allows the circuit to be energized, the inductive reactance created resistance is way up there- that's why they get hot. Solenoids (relay coils, the emission related guys, the two on the ACV, the starter solenoid, etc) waste a crapload of power for the job they do. I couldn't even venture a guess as to what kind of circuit impedance is "felt" by the ECU to "tell" it that the solenoid is energized...
Reply
Old Sep 26, 2004 | 01:19 AM
  #4  
RotaryResurrection's Avatar
Lives on the Forum
Tenured Member: 20 Years
Liked
iTrader: (8)
 
Joined: Oct 2003
Posts: 11,576
Likes: 27
From: Morristown, TN (east of Knoxville)
First...you are not recieving the CEL because of the removed solenoids. I've removed tons of emissions/solenoid racks with never a CEL on an FC. The only things to trigger an s5 CEL are OMP, TPS, pressure sensor, water thermosensor, and 02 sensor. You have another problem. Now, when you go to PULL codes, you WILL get the codes for the removed parts. BUt those will not set off a light.

FWIW, FD guys (including myself) running on the stock ecu who remove their solenoids (identical to FC ones) run 330ohm 1/2 watt resistors in place of the actual solenoid to fool the stock ecu. In that car, you WILL get a CEL from removal of these solenoids. So yes, that can be done.
Reply
Old Sep 26, 2004 | 09:03 AM
  #5  
poor_red_neck's Avatar
Thread Starter
Wait................What?
Tenured Member 10 Years
 
Joined: Apr 2003
Posts: 521
Likes: 0
From: Raleigh/Cary, NC - USA
Ok, forgot it was my TPS that was in there as well. Bought a used one off somebody here on the forum, installed and set to 1 ohm and it was still pulling a code for both. (After resetting the ECU).

so I dunno... i was just so used to pulling the tps code (for 6 months running w/o one) that I kinda ignored it.

Thanks for the info kevin
Reply
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Jeff20B
1st Generation Specific (1979-1985)
73
Sep 16, 2018 07:16 PM
Bauer778
3rd Generation Specific (1993-2002)
10
Nov 4, 2015 04:42 PM
alexdimen
3rd Generation Specific (1993-2002)
20
Oct 23, 2015 01:50 PM
FC_DREAMS
General Rotary Tech Support
7
Sep 9, 2015 06:24 PM




All times are GMT -5. The time now is 08:05 PM.