Just jumper that wire to test fuel pump and ECU. - Saab 900 Bulletin Board - Saabnet.com
The banner above is an advertisment - if it asks you to download software, please ignore.
Site News - 4/9 Saab Owners' Convention Day Pass Raffle | 3/26 M Car Covers (by State of Nine)
[General | Members | C900 | 9000 | NG900 & OG93 | 93 | 95 | NG95 | 99 | Sonett | Vintage Models | Clubs | Other Cars | FAQs | Gifts | Member Photo Galleries | Member Directory | Classifieds | Manuals | *Buddy Registry | *Mileage Registry | Polls | What's New | Raffle | Photo of the Month | Sponsors]

C900 Bulletin Board
1979-1993 & 94 Conv [Subscribe to Daily Digest]
(Search Author's Posts: e.g. Keyword:username)*Members Only

[Main C900 Bulletin Board | BBFAQ | Prev by Date | Next by Date | Post Followup ] Member Login / Signup - Members see fewer ads. - Latest Member Gallery Photos
Just jumper that wire to test fuel pump and ECU.
Like This Post: - Subscribe to Daily Digest for this Bulletin Board
Posted by RayF (more from RayF) on Wed, 1 Aug 2012 19:49:45 Share Post by Email
In Reply to: Re: OBDI codes / Justin, Saabnutt, Wed, 1 Aug 2012 19:19:46
Alert me when someone posts in this thread:
Members do not see ads below this line. - Help Keep This Site Online - Signup

Saabnutt - -

I believe you are overthinking this. The temporary jumpering I suggested is perfectly safe, and it will tell you with a minimum of trouble whether fuel pump or its relay are a problem, or not. Or whether ECU somehow is providing all else needed to run the car, except for signal to fuel pump.

I think by the way there's something a little off about your reasoning that that ground wire would show 12 volts instead of showing ground. If the ECU is sending the correct signal on it, which is ground, it should have no potential to ground when car is cranking or running. If you want to test that wire, test it when you're turning the key to Start, with starter turning the motor over.

With that little lilac wire jumpered to ground, your fuel pump should run with the key turned to On. You may hear its rumble back there in the tank, and you should also be able to hear the fuel rushing through the fuel rail as excess is returned to the tank thru the fuel pressure regulator.

It's the only wire from the ECU that is that color and gauge. I found it easiest to access it just beyond the multiplug at the ECU end, not the relay end, by pulling it out from the wire loom a little. I recommended the crimp tap because it lets you get to the wire without stripping the insulation or cutting the wire, and you can leave it installed for any future testing needs.

posted by 71.173.9...

Posts in this Thread:
Alert me when someone posts in this thread:
Members do not see ads below this line. - Help Keep This Site Online - Signup
Post a Followup

No Site Registration is Required to Post - Site Membership is optional (Member Features List), but helps to keep the site online
for all Saabers. If the site helps you, please consider helping the site by becoming a member.

Name: Member Login / Signup - Members see fewer ads. - Latest Member Gallery Photos
E-Mail: (Optional)
Re-Enter E-Mail: (Confidential & Secure - Not revealed to other users!)
Note: Please check your spam folder for BB responses.

Subject:

Posting rules are simple - No for sale/wanted ads may be posted here - use the site classifieds.
You may not cross-post your message to multiple BBs.
Not permitted: political/religious topics and being disrespectful (personal attacks, insults, etc...).
 Site Members do not see any red text, inline ad links, bottom of page anchor ads, box ads, or anti-spam check.

Message: (please no for sale/wanted classifieds - post those in the Saabnet.com Classifieds)
Links are now automatically made active, no need for any special code (or use the Option Link field below) - don't put links in () or end with a '.'
To add inline images to your post, use [img]http://www.domain.com/img.jpg[endimg] (or use the Optional Image Link field below).

Links are now automatically made active, no need for any special code (or use the Option Link field below) - don't put links in () or end with a '.'
To add inline images to your post above, use [img]http://www.domain.com/img.jpg[endimg] (or use the Optional Image Link field below).
Optional Link: (e.g. http://www.saabnet.com/)
Link Title: (Optional)
Optional Photo/Image Link: (e.g. http://www.saabnet.com/img.jpg)
Photo/Image to Upload: (Please be patient while file uploads)



StateOfNine.com
SaabClub.com
Jak Stoll Performance
M Car Covers
Ad Available

The content on this site may not be republished without permission. Copyright © 1988-2024 - The Saab Network - saabnet.com.
For usage guidelines, see the Mission & Privacy Notice.
[Contact | Site Map | Saabnet.com on Facebook | Saabnet.com on Twitter | Shop Amazon via TSN | Site Donations]

Random Saabnet.com Member Gallery Photos (Click Image)
This is a moderated bulletin board - Posting is a privilege, not a right. Unsolicited commercial postings are not allowed (no spam). Please, no For Sale or Wanted postings, SERIOUSLY. Classifieds are to be listed in The Saab Network Classifieds pages. This is a problem solving forum for over 250,000 Saab owners, so expect to see problems discussed here even though our cars are generally very reliable. This is not an anything goes type of forum. Saabnet.com has been a moderated forum since 1988. For usage guidelines, see the Saabnet.com Mission and Purpose Page. Please remember that you are not anonymous. Site Contact | Site Donations | Other Sites by SP - Poverty2Prosperity.org | Run Club Menlo Park | ScreenBot


Site Members do not see red text instructions, bottom of the page anchor ads, or box ads.
Click here to see all the Site Membership Benefits!