Home Forums Articles How To's FAQ Register
Go Back   Xoutpost.com > BMW SAV Forums > X5 (E53) Forum
Arnott
User Name
Password
Member List Premier Membership Search Today's Posts Mark Forums Read

Xoutpost server transfer and maintenance is occurring....
Xoutpost is currently undergoing a planned server migration.... stay tuned for new developments.... sincerely, the management


Reply
 
LinkBack Thread Tools Display Modes
  #11  
Old 11-17-2021, 12:36 PM
Member
 
Join Date: Nov 2021
Location: San Diego, CA
Posts: 14
Agent 14 is on a distinguished road
Got it. Man, Iíve been searching far and wide for this issue for a while.

That flow chart is the kind of info I was hoping to get here from all of the gurus.
Reply With Quote

Sponsored Links

  #12  
Old 11-17-2021, 12:52 PM
andrewwynn's Avatar
Member
 
Join Date: Jun 2015
Location: Racine, WI
Posts: 8,824
andrewwynn will become famous soon enough
Code:
Secondary air system monitor
Automatic monitoring is carried out to ensure that the secondary air system is functioning correctly. For this purpose, operation of the secondary air injection and of the shut-off and air switch-over valves must be monitored each time they are activated. The secondary air injection serves as an exhaust gas treatment during the engine warm-up phase. For this purpose, fresh air is injected directly into the exhaust manifold to ensure the catalytic converter heats up at a faster rate.

Depending on the exhaust requirement, the air volume blown into the secondary air system is measured by means of the secondary hot-film air-mass sensor.

Shortly after the engine is started, the secondary air pump is activated by the SLP relay. The time until it is switched on is dependent on the following fringe conditions:

- Engine temperature

- Load signal

- Engine speed

Monitoring principle
The oxygen sensor voltage is monitored in the engine control unit during activation of the secondary air pump. During problem-free operation of the secondary air system, the oxygen sensor voltage is primarily in the lean range.

At regular intervals (every 20 ms), the oxygen sensor voltage is registered within the control unit. Each measurement in which the oxygen sensor voltage is registered as being in the lean range is counted by an internal counter. If this count exceeds a predefined threshold, the system is recognised as being fully operational. If this threshold is not reached the engine control unit assumes there is a fault in the secondary air system. An entry is made in the fault code memory.
All I could find on the SAP on newtis. (other than wiring diagram).

Hint is it should either pass or fail bit you aren't getting either.

It seems pre 2003 with no MAF on SAP the system confirms the blower is working by making sure O₂ reads lean but why is it not flipping the monitor to fail or ok look into the inputs mentioned in the quote above. Load/temp/RPM.

I would also look into force a code unplugging O₂ if the sap valve/pump unplug trick doesn't work.

Stuff that isn't quite broken is always most frustrating. If it would just damn break you can replace it.
__________________
E53 / M54 2001 3.0i gas LHD (pair of them: his & her)
Reply With Quote
  #13  
Old 11-17-2021, 01:29 PM
Member
 
Join Date: Nov 2021
Location: San Diego, CA
Posts: 14
Agent 14 is on a distinguished road
Hell yeah, thank you so much. This is great info. Its really the last line that is worth reading twice. Points to a "not quite failing" O2 sensor.

Im going to do some testing and digging. Ill be back to report on the issue for the sake of future googles.
Reply With Quote
  #14  
Old 11-17-2021, 03:10 PM
Member
 
Join Date: Mar 2006
Location: Washington, DC
Posts: 154
nick325xit 5spd is on a distinguished road
Have you tried idling it for like 15 minutes after a cold start?
__________________
2011 M3
2006 Sierra 2500HD 4WD LBZ/Allison
2004 X5 3.0i 6MT
1995 M3 S50B32
1990 325is
1989 M3 S54B32

Hers:
1989 325iX
1996 911 Turbo


Reply With Quote
  #15  
Old 11-17-2021, 03:23 PM
Member
 
Join Date: Jun 2021
Location: Austin, TX
Posts: 322
X5chemist is on a distinguished road
My X5 set codes for the same non completed test. The problem was not enough air flow (Foxwell code readings). I went through 3 pumps. The first two were cheap RockAuto knock offs. The third and current one is their most expensive pump available. The third one passed and set emissions. The OEM was changed due to failing bearings.
__________________
'06 X5 3.0i - bought @143,123 miles (12/26/20)
Reply With Quote
  #16  
Old 11-17-2021, 03:27 PM
andrewwynn's Avatar
Member
 
Join Date: Jun 2015
Location: Racine, WI
Posts: 8,824
andrewwynn will become famous soon enough
There is a reason those pumps are so pricy. They have to generate enough volume and pressure to overcome the exhaust pressure and then some.

I still think OEM is stupid expensive. I would probably get a used one vs. buy OEM. (especially knowing how to use a 5 series or 7 series model on the e53) (more source material)
__________________
E53 / M54 2001 3.0i gas LHD (pair of them: his & her)
Reply With Quote
  #17  
Old 11-17-2021, 05:03 PM
Member
 
Join Date: Nov 2021
Location: San Diego, CA
Posts: 14
Agent 14 is on a distinguished road
Quote:
Originally Posted by nick325xit 5spd View Post
Have you tried idling it for like 15 minutes after a cold start?

Yes. Few times.

Iíll source a pump from my local dismantler and see if that helps.
Reply With Quote
  #18  
Old 11-17-2021, 05:51 PM
Member
 
Join Date: Sep 2020
Location: Woodinville, WA
Posts: 66
Corellian Corvette is on a distinguished road
Quote:
Originally Posted by andrewwynn View Post
I still think OEM is stupid expensive. I would probably get a used one vs. buy OEM. (especially knowing how to use a 5 series or 7 series model on the e53) (more source material)
PLEASE SAY MORE
Reply With Quote
  #19  
Old 11-17-2021, 08:07 PM
andrewwynn's Avatar
Member
 
Join Date: Jun 2015
Location: Racine, WI
Posts: 8,824
andrewwynn will become famous soon enough
I have a write up on xo.

When wife's SAP failed I had one from 7 series same vintage and it needed just a little fine tuning to work.

I had to cut a tiny bit of plastic of the back of the headlight hardware and had to drill new holes to mount (it's about 30į different angle), however was a simple job and i already had the pump.

I think it will be a lot easier = cheaper to find one from a 5 or 7 series. The outlet pipe was compatible. It doesn't use the remote mounted filter the filter is built in.
__________________
E53 / M54 2001 3.0i gas LHD (pair of them: his & her)
Reply With Quote
  #20  
Old 11-21-2021, 04:07 PM
Member
 
Join Date: Nov 2021
Location: San Diego, CA
Posts: 14
Agent 14 is on a distinguished road
Ok, did some more diagnosis. The pump is fine I confirmed with known good one. Check valve work too. I put vacuum on it and I could blow air through.

I pulled O2s and cleaned them. They are very clean and new ish.

Iím thinking the rigid vac line going to the rear of the motor is a problem.

However, This morning I tested by blocking off that vacuum line to the back of the motor disconnecting it from the pump and simulating five psi on the pump to open the check valve. Itís still not clearing. I am watching that monitor not complete. There are no other engine codes still.

Any more thoughts?


Sent from my iPhone using Tapatalk
Reply With Quote
Reply

Bookmarks

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
Trackbacks are On
Pingbacks are On
Refbacks are On





All times are GMT -4. The time now is 05:57 PM.
vBulletin, Copyright 2021, Jelsoft Enterprises Ltd. SEO by vBSEO 3.6.0
© 2017 Xoutpost.com. All rights reserved. Xoutpost.com is a private enthusiast site not associated with BMW AG.
The BMW name, marks, M stripe logo, and Roundel logo as well as X3, X5 and X6 designations used in the pages of this Web Site are the property of BMW AG.
This web site is not sponsored or affiliated in any way with BMW AG or any of its subsidiaries.