Jump to content

The RennTech.org community is Member supported!  Please consider an ANNUAL donation to help keep this site operating.
Click here to Donate

Welcome to RennTech.org Community, Guest

There are many great features available to you once you register at RennTech.org
You are free to view posts here, but you must log in to reply to existing posts, or to start your own new topic. Like most online communities, there are costs involved to maintain a site like this - so we encourage our members to donate. All donations go to the costs operating and maintaining this site. We prefer that guests take part in our community and we offer a lot in return to those willing to join our corner of the Porsche world. This site is 99 percent member supported (less than 1 percent comes from advertising) - so please consider an annual donation to keep this site running.

Here are some of the features available - once you register at RennTech.org

  • View Classified Ads
  • DIY Tutorials
  • Porsche TSB Listings (limited)
  • VIN Decoder
  • Special Offers
  • OBD II P-Codes
  • Paint Codes
  • Registry
  • Videos System
  • View Reviews
  • and get rid of this welcome message

It takes just a few minutes to register, and it's FREE

Contributing Members also get these additional benefits:
(you become a Contributing Member by donating money to the operation of this site)

  • No ads - advertisements are removed
  • Access the Contributors Only Forum
  • Contributing Members Only Downloads
  • Send attachments with PMs
  • All image/file storage limits are substantially increased for all Contributing Members
  • Option Codes Lookup
  • VIN Option Lookups (limited)

Recommended Posts

Greetings from Finland

 

Car is blowing the 5A control circuit fuse for the secondary air injection pumps and therefore throwing the P2259 code, it also has intermittent "brake booster fault" and I have a feeling these are related to each other. I'm suspecting an relay issue since the pumps are fine(tested) and the fuse is for the control circuit. I also removed and tested the vacuum pump for the brake booster and it's also fine. '

 

Has anyone had any similar issues? Where's the control relay located? I did look for info on the site (a great one!) but so far no good.

 

I'm also looking for an exhaust upgrade, sec-decat and rear section to be precise, but the pricing on those I have found has been plain silly. Any helpfull directions?

Edited by A.H.
Link to post
Share on other sites
    You can remove these ads by becoming a Contributing Member.

  • Admin

F12 (5A) controls the secondary air pumps as well as the water after-run pump relays.

I would pull the relays individually (secondary air - then after-run pump) and see if you can narrow down the problem area.

Link to post
Share on other sites

Secondary air pumps have been known to fail.

The impellers disintegrate and prevent the motor from turning.

You could try electrically disconnecting the pumps and replace the fuse to see what happens.

Link to post
Share on other sites

I have tested the pumps and those are perfectly fine. Jammed pump would drain a whole lot of current and most certainly blow out the large feed fuse for the relay(s).

 

The problem I'm having is on the control circuit for the relays. The current present in the control circuit should be very minimal, therefore the 5A fuse. I would gues that ecm applies ground to the relays when the circuit needs to be energized, only thing that can blow the control circuit fuse is a short to ground between the fuse and the relay or a short to ground IN the relay. Failed coil in the relay would very possibly cause this. Sec-air-pump relays are very simple, and i have to say very robust in construction (70A..) and I doubted i would find the culprit there - as I did not.

 

Actually I could measure the drawn current to the relays separately, I did test them from a battery unfused. I will dig into this more this evening, hopefully i'll get it sorted soon as the bugger seems to disable closed loop lambda operation in any case of a malfunction - without enabling mil- light. - no good.

 

When i'll get this storted i can get to changing out the valveblock in the autobox..

Link to post
Share on other sites
  • 1 month later...

Finally got around looking further in this;

 

Cold start; remove pump relays and afterrun coolant pump relay, fuse in place - Start the car - Fuse blows immediately (no relays attached). BUT if I immediately plug in all the relays, and replace the Fuse, both air pumps start, fuse does NOT blow and all is well in the kingdom of waterbox.

 

And it gets even more interesting; Last time I fiddled with these It seems to have cured itself, even though I did nothing??

 

My best bet is that the insulation on the control wiring is cracked or stripped in the waterbox, and moisture&dirt has been causing a short to ground condition in the circuit. We'll see if it will come back someday.

 

Anyway for the time being there are no issues, sec air pumps work every morning, no codes or blown fuses. Car runs flawless and on E85. (I have a Finnish Flexfuel conversion kit on it.)

 

 

Link to post
Share on other sites
  • 3 years later...

I am having this same set of issues - brake booster light, secondary air pump code/CEL, and the coolant after run pump is not running. 04 CTT.

 

I wrongly assumed that the coolant after run pump motor died and replaced the pump. After reading this thread, I found the F12 5A fuse to be blown. I replaced the fuse, started the car, and the brake booster pump works again but the coolant after run pump still does not function in "rest mode". I could not test if the SAI pumps work as the car was already warm. Visually, the relays look fine - no corrosion or obvious defect. I have a voltmeter, is there a way to test these? 

 

Can you guys please offer further guidance on how to troubleshoot this? My car heater is very weak at idle without the pump running and it is getting cold in the NE! 

Edited by dpatel710
Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.