The Subaru SVX World Network   SVX Network Forums
Live Chat!
SVX or Subaru Links
Old Lockers
Photo Post
How-To Documents
Message Archive
SVX Shop Search
IRC users:
SVXBot

Go Back   The Subaru SVX World Network > SVX Main Forums > Technical Q & A

Reply
 
Thread Tools Display Modes
  #1  
Old 11-21-2018, 02:55 PM
theflystyle's Avatar
theflystyle theflystyle is offline
Registered User
Subaru Bronze Contributor
 
Join Date: Jul 2008
Location: Fulton, MD
Posts: 630
Registered SVX
Trunk Fuel Resistor

Hello,

I am having a hard time finding the Subaru part number for the trunk fuel resistor (the one with the two long white wires) underneath the rear deck. The part number on the unit itself is A15-000R20 but I couldn't cross reference it with any Subaru part numbers.

Thanks!
__________________
1994 SVX LSi
JDM Tailbar and Grill, Clear Corners, 15min-mod, Nevin Blue RSB, G-FORCE SPORT COMP-2 Tires, Phenolic Spacers (Manifold & Throttle Body), SS Brake Lines, Maniac Electric Motors 160A Alternator
1994 Legacy L
WRX Wheels
2008 Legacy 3.0R
HID, Bilstein F/R, WhiteLine LCA Bushings, Potenza RE970AS PolePosition Tires
Reply With Quote
  #2  
Old 11-22-2018, 12:21 PM
theflystyle's Avatar
theflystyle theflystyle is offline
Registered User
Subaru Bronze Contributor
 
Join Date: Jul 2008
Location: Fulton, MD
Posts: 630
Registered SVX
Re: Trunk Fuel Resistor

Finally found it listed under "Engine and Cooling" then "Relay & Sensor (Engine)" on the Subaru Parts website. Unfortunately the part is no longer available.

For posterity, here is the part number information:

Resistor Assembly (rear trunk lid) - 22654AA060
Fuel Control Module (rear trunk lid) - 22637AA000
Relay Assembly (round under dash) - 82501GA240
Relay Assembly (square under dash) - 25232AA020

For those wondering, my car died while driving. Had it towed to my garage and began chasing the issue. Fuel was not being delivered to the engine (past the fuel filter) so I then checked the relays under the dash. Followed by verifying power to the fuel pump. After that I tried disconnecting the rear deck Fuel Control Module and the car started right up. This leads me to believe the Fuel Control Module is to blame.
__________________
1994 SVX LSi
JDM Tailbar and Grill, Clear Corners, 15min-mod, Nevin Blue RSB, G-FORCE SPORT COMP-2 Tires, Phenolic Spacers (Manifold & Throttle Body), SS Brake Lines, Maniac Electric Motors 160A Alternator
1994 Legacy L
WRX Wheels
2008 Legacy 3.0R
HID, Bilstein F/R, WhiteLine LCA Bushings, Potenza RE970AS PolePosition Tires
Reply With Quote
  #3  
Old 11-22-2018, 12:29 PM
RedLionSVX's Avatar
RedLionSVX RedLionSVX is offline
Registered User
 
Join Date: Aug 2018
Location: Red Lion
Posts: 36
Re: Trunk Fuel Resistor

Wow, how many miles on your car?
Attached Files
File Type: pdf fuel.pdf (470.8 KB, 27 views)
Reply With Quote
  #4  
Old 11-23-2018, 07:04 AM
theflystyle's Avatar
theflystyle theflystyle is offline
Registered User
Subaru Bronze Contributor
 
Join Date: Jul 2008
Location: Fulton, MD
Posts: 630
Registered SVX
Re: Trunk Fuel Resistor

She has 115K but is kept in the garage and never driven in any precipitation.

That attachment does not have the parts I listed in case you were wondering.

I would really like to find a test for the fuel tank resistor. I didn't see anything in the factory service manuals yet.
__________________
1994 SVX LSi
JDM Tailbar and Grill, Clear Corners, 15min-mod, Nevin Blue RSB, G-FORCE SPORT COMP-2 Tires, Phenolic Spacers (Manifold & Throttle Body), SS Brake Lines, Maniac Electric Motors 160A Alternator
1994 Legacy L
WRX Wheels
2008 Legacy 3.0R
HID, Bilstein F/R, WhiteLine LCA Bushings, Potenza RE970AS PolePosition Tires
Reply With Quote
  #5  
Old 11-28-2018, 11:04 PM
SacSVX SacSVX is offline
Registered User
 
Join Date: Mar 2016
Location: sacramento
Posts: 30
Re: Trunk Fuel Resistor

I’ve been having the same issue where the car dies. After long threads of MAF sensor, I "believe" I have traced it to a fuel supply issue (I still haven't tested it). There have been multiple threads on this peculiar problem.

The car starts normal from cold, but when it heats up (especially during the summer) after driving, it stalls out and cannot be restarted until it cools down. I've gotten good at stabbing the throttle to prevent it from stalling out when I sense a failure, which is what led me to look at fuel delivery issues.

Here's the weird part. When I got the engine running normal, I would unplug the fuel control module from under the deck lid, yet the car would continue to run normally. H Am I missing something? Can someone elaborate?

.

Last edited by svxcess; 12-05-2018 at 08:22 PM.
Reply With Quote
  #6  
Old 11-28-2018, 11:41 PM
Trevor's Avatar
Trevor Trevor is offline
Registered User
 
Join Date: Feb 2002
Location: Auckland, New Zealand
Posts: 5,103
Registered SVX
Re: Trunk Fuel Resistor

Quote:
Originally Posted by SacSVX View Post

I’ve been having the same issue where the car dies. After long threads of MAF sensor, I "believe" I have traced it to a fuel supply issue (I still haven't tested it). There have been multiple threads on this peculiar problem.

The car starts normal from cold, but when it heats up (especially during the summer) after driving, it stalls out and cannot be restarted until it cools down. I've gotten good at stabbing the throttle to prevent it from stalling out when I sense a failure, which is what led me to look at fuel delivery issues.

Here's the weird part. When I got the engine running normal, I would unplug the fuel control module from under the deck lid, yet the car would continue to run normally. H Am I missing something? Can someone elaborate?
Several years ago I explained in a post exactly how the system works, but I no longer have the circuit diagram. If this can be provided I will again do so.

Sincerely, Trevor.
__________________
Trevor, New Zealand.

As a child, on cold mornings I gladly stood in cowpats to warm my bare feet, but I detest bull$hit!

Last edited by svxcess; 12-05-2018 at 08:23 PM.
Reply With Quote
  #7  
Old 12-02-2018, 01:17 PM
theflystyle's Avatar
theflystyle theflystyle is offline
Registered User
Subaru Bronze Contributor
 
Join Date: Jul 2008
Location: Fulton, MD
Posts: 630
Registered SVX
Re: Trunk Fuel Resistor

Quote:
Originally Posted by Trevor View Post
Several years ago I explained in a post exactly how the system works but I no longer have the circuit diagram. If this can be provided I will again do so.

Sincerely, Trevor.

Attached is the only circuit diagram I found with the resistor and fuel control module included. What really bothers me is that the resistance measured on the fuel resistor (R34 in the diagram) reads a resistance of 1.2 ohm (.2 is my multimeter’ss probe resistance). Yet when I unplug it, the car starts. When its plugged in it does not.

.
Attached Images
File Type: png diagram.png (50.0 KB, 23 views)
__________________
1994 SVX LSi
JDM Tailbar and Grill, Clear Corners, 15min-mod, Nevin Blue RSB, G-FORCE SPORT COMP-2 Tires, Phenolic Spacers (Manifold & Throttle Body), SS Brake Lines, Maniac Electric Motors 160A Alternator
1994 Legacy L
WRX Wheels
2008 Legacy 3.0R
HID, Bilstein F/R, WhiteLine LCA Bushings, Potenza RE970AS PolePosition Tires

Last edited by svxcess; 12-05-2018 at 08:26 PM. Reason: Better quality attachment
Reply With Quote
  #8  
Old 12-02-2018, 03:49 PM
Trevor's Avatar
Trevor Trevor is offline
Registered User
 
Join Date: Feb 2002
Location: Auckland, New Zealand
Posts: 5,103
Registered SVX
Re: Trunk Fuel Resistor

Quote:
Originally Posted by theflystyle View Post
Attached is the only circuit diagram I found with the resistor and fuel control module included. What really bothers me is that the resistance measured on the fuel resistor (R34 in the diagram) reads a resistance of 1.2 ohm (.2 is my multimeter’s probe resistance). Yet when I unplug it, the car starts. When its plugged in it does not.
Great, exactly what I needed.

When the ignition is turned on the fuel pump is supplied with a positive supply via the fuel pump relay and fuses SB4 and No. 16 but overall switching of the pump relay and therefore the pump, depends on the ECU completing the negative ground circuit via d23.

The pump receives its negative supply via two alternatives, i.e. the resistor R34 or the fuel pump modulator switching transistors which are controlled via the ECU.

The resistor will provide a reduced voltage and therefore limited pump speed in the event of the pump modulator or its control failing. The resistor will also prevent full zero voltage in respect of pulse width modulation speed control of the pump.

Under normal circumstances pump speed and therefore pressure, will be controlled via the modulator and ultimately by the ECU by means of pulse width modulation.

The pump will run at a reduced speed with the pump modulator disconnected.

I presume that you are reading the value of the resistor with it unplugged. It would appear certain that the resistance value is too low but I do not have the specified figure. This would result in the resistor circuit overriding control via the modulator as would a short circuit to ground within the resistor housing.

Can you locate the correct specified value of the resistor?
__________________
Trevor, New Zealand.

As a child, on cold mornings I gladly stood in cowpats to warm my bare feet, but I detest bull$hit!

Last edited by svxcess; 12-05-2018 at 08:26 PM.
Reply With Quote
  #9  
Old 12-04-2018, 06:57 PM
theflystyle's Avatar
theflystyle theflystyle is offline
Registered User
Subaru Bronze Contributor
 
Join Date: Jul 2008
Location: Fulton, MD
Posts: 630
Registered SVX
Re: Trunk Fuel Resistor

Trevor,

All your information has been greatly appreciated. When reading your explanation it makes sense when paired with the diagram.

Regarding any specs or values for the resistor or the modulator, I have not been able to find anything. I would love to see if anyone had a stock unit they could test so that we could have a known good unit to compare to.

I am going to hopefully get a replacement used unit to test soon. I will provide updates as they occur.
__________________
1994 SVX LSi
JDM Tailbar and Grill, Clear Corners, 15min-mod, Nevin Blue RSB, G-FORCE SPORT COMP-2 Tires, Phenolic Spacers (Manifold & Throttle Body), SS Brake Lines, Maniac Electric Motors 160A Alternator
1994 Legacy L
WRX Wheels
2008 Legacy 3.0R
HID, Bilstein F/R, WhiteLine LCA Bushings, Potenza RE970AS PolePosition Tires
Reply With Quote
  #10  
Old 12-04-2018, 09:58 PM
Trevor's Avatar
Trevor Trevor is offline
Registered User
 
Join Date: Feb 2002
Location: Auckland, New Zealand
Posts: 5,103
Registered SVX
Re: Trunk Fuel Resistor

Quote:
Originally Posted by theflystyle View Post
Trevor,

All your information has been greatly appreciated. When reading your explanation it makes sense when paired with the diagram.

Regarding any specs or values for the resistor or the modulator, I have not been able to find anything. I would love to see if anyone had a stock unit they could test so that we could have a known good unit to compare to.

I am going to hopefully get a replacement used unit to test soon. I will provide updates as they occur.
I find this situation very sad, as years ago there would have been many members keen and able to assist you. There must be numerous parts cars out there with a resistor available for easy removal.

Furthermore, surely there is someone who can unplug and measure the resistor in their operational SVX. If I still had my car, doing so I would have involved less time than that expended in posting the required messages talking about the issue. LOL

Probably it would have been preferable for the post to have appeared in the Technical section, but this surely is not a real problem.

I would expect the resistor value to be in two figures but it can it not be estimated without full details covering the pump motor and its requirements.

THIS POST LAUNCHES AS A ROCKET OF DISTRESS!
__________________
Trevor, New Zealand.

As a child, on cold mornings I gladly stood in cowpats to warm my bare feet, but I detest bull$hit!

Last edited by svxcess; 12-05-2018 at 08:29 PM. Reason: Typo
Reply With Quote
  #11  
Old 12-05-2018, 08:28 PM
svxcess's Avatar
svxcess svxcess is offline
Pristine Green Polo Machine
Alcyone Gold Contributor
 
Join Date: Feb 2001
Location: Westminster, MD
Posts: 6,562
Significant Technical Input Registered SVX Classic SVX
Re: Trunk Fuel Resistor

.
Moved to the Technical Q&A forum.
.
__________________
.
Subaru Ambassador

1996 Polo Green LSi #216...138,100 miles...

JFICX8659TH100216JF1CX8659TH100216........Mfg. Date: 11/1995......... Service Date: January 2, 1997

"The Pristine Green Polo Machine"

First Polo Green on the Network
First Clear front turn signals, JDM Alcyone hood emblem, rear panel, and BOXER engine cover on the Network (US) (2000)
First 5000K HID factory fog lights (2007)
First SVX JDM BBS wheels on a USDM SVX (2013)

HID lighting (5000K) for headlight and H3 fog lights, PIAA SuperExtreme 120W high beams, rebuilt EG33 longblock, Cometic head gaskets, Phase II flexplate, 160A high-output alternator in aluminum-ceramic coated case, new design alternator wiring upgrade v.4, rare factory headlight protectors, refinished JDM BBS mesh aluminum wheels and custom, polished billet aluminum new hex center caps, LED grille mod, Raceconcepts dimpled/slotted rotors, Akebono ceramic pads, Goodridge S/S braided brake lines, Smallcar Stage 1 shift kit, ThermalTech aluminum/ceramic-coated valve covers, Energy Suspension urethane front & rear swaybar bushings, Bontrager22 rear swaybar with QS Components Chromoly Teflon/Kevlar endlinks, "$15.00/5 minute" suspension mod. Hella Supertone horns, Custom stainless steel exhaust system with 2" headpipes, Magnaflow cats, AeroTurbine AR25 resonator /AWD "Bullet" muffler.


R.I.P. 2010 Subaru Outback Limited 2.5 CVT...338,000 miles. Totaled by a COW March 4, 2016
2014 Hyundai Elantra Limited ...76,000 miles. Actually quieter and smoother than the SVX


5th Registered Network member 2/21/2001

My NEW locker..I...My Email..I..Wikipedia/SVX .I..SVXNATION

.
Reply With Quote
  #12  
Old 12-05-2018, 11:00 PM
Trevor's Avatar
Trevor Trevor is offline
Registered User
 
Join Date: Feb 2002
Location: Auckland, New Zealand
Posts: 5,103
Registered SVX
Re: Trunk Fuel Resistor

Quote:
Originally Posted by svxcess View Post
.
Moved to the Technical Q&A forum.
.
Thanks friend, compliments of the season.
__________________
Trevor, New Zealand.

As a child, on cold mornings I gladly stood in cowpats to warm my bare feet, but I detest bull$hit!
Reply With Quote
  #13  
Old 12-06-2018, 02:29 PM
irox irox is offline
Registered User
 
Join Date: Jun 2016
Location: CA
Posts: 51
Re: Trunk Fuel Resistor

If I get a chance this weekend, I'll throw a ohm meter across mine and see what it says.

What's the quickest way to access it? (I know the vague location.)

Cheers,
Ian.
Reply With Quote
  #14  
Old 12-06-2018, 02:58 PM
theflystyle's Avatar
theflystyle theflystyle is offline
Registered User
Subaru Bronze Contributor
 
Join Date: Jul 2008
Location: Fulton, MD
Posts: 630
Registered SVX
Re: Trunk Fuel Resistor

Quote:
Originally Posted by irox View Post
If I get a chance this weekend, I'll throw a ohm meter across mine and see what it says.

What's the quickest way to access it? (I know the vague location.)

Cheers,
Ian.
that would be greatly appreciated. Its under the rear deck, behind the trunk liner between the two speakers. I ended up taking the pop-its off to allow the whole cover to come off. I don't know if there was/is an easier way.
__________________
1994 SVX LSi
JDM Tailbar and Grill, Clear Corners, 15min-mod, Nevin Blue RSB, G-FORCE SPORT COMP-2 Tires, Phenolic Spacers (Manifold & Throttle Body), SS Brake Lines, Maniac Electric Motors 160A Alternator
1994 Legacy L
WRX Wheels
2008 Legacy 3.0R
HID, Bilstein F/R, WhiteLine LCA Bushings, Potenza RE970AS PolePosition Tires
Reply With Quote
  #15  
Old 12-06-2018, 05:49 PM
Trevor's Avatar
Trevor Trevor is offline
Registered User
 
Join Date: Feb 2002
Location: Auckland, New Zealand
Posts: 5,103
Registered SVX
Re: Trunk Fuel Resistor

Quote:
Originally Posted by theflystyle View Post
that would be greatly appreciated. Its under the rear deck, behind the trunk liner between the two speakers. I ended up taking the pop-its off to allow the whole cover to come off. I don't know if there was/is an easier way.
Also special thanks from me Ian.

Please make sure that the resistor is disconnected when you measure it, otherwise existing circuitry in parallel could upset the reading. No doubt I am stating the obvious and asking you to suck eggs. LOL
__________________
Trevor, New Zealand.

As a child, on cold mornings I gladly stood in cowpats to warm my bare feet, but I detest bull$hit!

Last edited by Trevor; 12-06-2018 at 08:33 PM. Reason: Addition
Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -6. The time now is 05:42 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2018, vBulletin Solutions, Inc.
2001-2015 SVX World Network
(208)-906-1122