LOST JEEPS
http://www.lostjeeps.com/forum/phpBB3/

P1252 & P0299
http://www.lostjeeps.com/forum/phpBB3/viewtopic.php?f=5&t=80848		 Page 1 of 1
Author:  joelukex4 [ Wed Dec 10, 2014 10:11 pm ]
Post subject:  P1252 & P0299
I realize this is an old topic but new to me as I never had an issue before in 50K miles. CRD has 87K miles , GDE Eco tune and exhaust. Everything else is stock. Check engine light recently went on and multiple cycles has not turned it off. Had codes ran and P1252 & P0299 came up. Should I start with the Vacuum reservoir solenoid first? What about the ASD relay? Still have original hoses but they don't sound like they are leaking.
Author:  flash7210 [ Wed Dec 10, 2014 10:23 pm ]
Post subject:  Re: P1252 & P0299
Sounds like one of your vacuum solenoids went bad.
It's usually the bigger one and it starts making a loud buzzing noise when it goes bad.
Author:  WWDiesel [ Wed Dec 10, 2014 11:10 pm ]
Post subject:  Re: P1252 & P0299
P1252 Jeep Description
Possible causes
- Faulty Vacuum Reservoir Solenoid
- Vacuum Reservoir Solenoid harness is open or shorted
- Vacuum Reservoir Solenoid circuit poor electrical connection
The Engine Control Module (ECM) detected a short to ground on the Vacuum Reservoir Solenoid control circuit
Author:  GreenDieselEngineering [ Thu Dec 11, 2014 8:36 am ]
Post subject:  Re: P1252 & P0299
Trace the vacuum line back from turbo to boost evm (has little air filter on bottom and blue isolator), then to the reservoir evm (all black). Take the vacuum supply off the black evm and plug it into the boost evm in the port labeled "vac". This by-passes the on/off evm and should restore boost and drivability while you order a new black evm.
Author:  gmctd [ Thu Dec 11, 2014 2:53 pm ]
Post subject:  Re: P1252 & P0299
joelukex4 wrote:
I realize this is an old topic but new to me as I never had an issue before in 50K miles. CRD has 87K miles , GDE Eco tune and exhaust. Everything else is stock. Check engine light recently went on and multiple cycles has not turned it off. Had codes ran and P1252 & P0299 came up. Should I start with the Vacuum reservoir solenoid first? What about the ASD relay? Still have original hoses but they don't sound like they are leaking.

Usual failure of the vacuum hoses is deterioration due to under-hood heat and ozone - for some unexplainable reason, when the hoses develop a leak it is invariably on the bottom unseen side of the hose - gravity??

Pull each one and look for pin-hole to pencil-tip size hole in the under-side

Also loose-fit on the hose barbs due to ozone-related hose expansion at those points

These KJ's are now 9 and 10yrs old, so prolly wouldn't hurt to replace all the vacuum hosery across the board
Author:  joelukex4 [ Thu Dec 11, 2014 8:54 pm ]
Post subject:  Re: P1252 & P0299
I just removed the vacuum hose and bypassed the solenoid. When I removed the hose I could here the vacuum release. Does this indicate the vacuum solenoid was still functioning?
Author:  gmctd [ Thu Dec 11, 2014 9:01 pm ]
Post subject:  Re: P1252 & P0299
Also seems to indicate the hose is good
- raise the VVT linkage, place your fingertip over the hose barb, release the linkage: if diaphragm is good, linkage will hold
- place your fingertip over the hose-end with engine running: if it makes a hickey on your fingertip, hose is good, no leaks

However, the solenoid vave might not leak, but the coil is bad, not energizing the solenoid valve - or, after all these years, coil is good but the solenoid shuttle may refuse to travel = no valving action

This is always a probem with PWM-actuated devices
Author:  joelukex4 [ Tue Jan 20, 2015 4:51 pm ]
Post subject:  Re: P1252 & P0299
I bypassed the vacuum solenoid by moving the vacuum line and it seems to run better. Which solenoid needs replacing?

Turbocharger Vacuum Modulator 52109543AA or Vacuum Solenoid 4606226AC
Author:  gmctd [ Tue Jan 20, 2015 5:01 pm ]
Post subject:  Re: P1252 & P0299
joelukex4 wrote:
I bypassed the vacuum solenoid by moving the vacuum line and it seems to run better. Which solenoid needs replacing?

Turbocharger Vacuum Modulator 52109543AA or Vacuum Solenoid 4606226AC

The one you bypassed - has two (count'em: 2) hoses - Vac Sol 4606226AC

viewtopic.php?p=854625#p854625
Author:  rockstar2169 [ Tue Jun 09, 2020 7:56 pm ]
Post subject:  Re: P1252 & P0299
I know this post is very old but i stumbled across it and am having a very hard time figuring out what green diesel engineering stated in one of the threads. it was something about by-passing the vacuum line coming off the turbo. i'm sorry but his description isn't very helpful. can someone please help me with a more clear description of what hose gets pulled from where. thank you. i've ordered both pn: 52109543aa and 4606226ac
Author:  WWDiesel [ Tue Jun 09, 2020 11:43 pm ]
Post subject:  Re: P1252 & P0299
From one of my older posts:
You can temporarily bypass the No. 2 item, vacuum reservoir for a test as follows:
Remove hose from "A" location and connect it to "B" location for test.

Turbo Vacuum solenoid test procedure

Failure of the vacuum reservoir solenoid (a.k.a. solenoid secondary runner valve per the parts fiche PN(PN 4606226AC) ) can produce several MIL/CEL codes and result is turbo boost problems. A temporary solution and diagnosis is to bypass that solenoid by rerouting vacuum lines as in the picture below:

By disconnecting the hose from where the red arrow is (location A) and re-connecting it where the yellow arrow is (Location B port on modulator). If that solves the problem then leave the hoses in the new/temporary configuration and order a replacement solenoid. In the interim the vehicle may be driven; the CEL will remain until you replace the on/off solenoid. The only benefit that part provides is overnight storage of vacuum in the plastic reservoir so the turbo has vacuum immediately during the start. Without it you have a 2-10 second wait before the engine vacuum pump evacs the lines enough for the turbo vanes to move. Once the replacement solenoid is installed put the hose(s) back the way they were originally.

GDE's writeup for this says "By-passing of the on/off solenoid is very straight forward. Trace the vacuum line output from the black plastic reservoir to the input of the on/off solenoid. Remove this vacuum line and plug it directly into the turbo EVM on the port labeled "VAC". The turbo EVM is the one with the blue rubber isolator and vacuum line running directly to turbo."

Also, you should probably trace the small plastic vacuum impulse line from the turbo vane modulator to the turbo van controller for a melted, collapsed, or cracked vacuum line as in this post at: viewtopic.php?f=5&t=61240
Several including myself have found problems with this line!

ImageImage
Author:  rockstar2169 [ Wed Jun 10, 2020 8:30 am ]
Post subject:  Re: P1252 & P0299
WWdiesel thank you so much for that. i now know where i was confused with gde's description. i'll be trying that later today. once those parts come in i will replace that hose you suggested.
i'm only getting the P0299 code and one of those vacuum parts was making the humming noise, up until last week. and thats when we started getting no low end boost. thanks again.
Page 1 of 1 All times are UTC - 5 hours [ DST ]
Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group
http://www.phpbb.com/