P1252

kobusdP · **Posted:** Sun May 30, 2010 10:24 am

I searched this website and found valuable information on stuff to look at.

However, I need to ask.

It ran fine on Friday night. Saturday I gave the Jeep its Bi monthly cleaning which includes the engine. I used engine cleaner and a high pressure hose.

2 Hours later when I drove off I saw the MIL on. No boost. No smoke.

What did I wet? Obviously it has to be that.

The vacuum hose to the turbo is good. When I suck on it the wastegate moves and I can form a vacuum to hold the pressure.

The hose from the air filter to the turbo is SHOT! at the 90 degree bend on the turbo it is completelyruined.

Lots of oil in the pipe from turbo to intercooler. Found that the Shell looking diaghpram on the head was filthy. I cleaned it.

I sprayed all the electrical connections with some spray for water. Only found water in one but the water trap filter.

Clean both sensors in the air filter box.

Will be looking for the EGR as pointed out in one of the posts.

When I reset the code, it lights up immideately when I start up and idle.

What else can I look for?

Thank you in advance

GreenDieselEngineering · **Joined:** Sun Jun 07, 2009 5:10 pm **Posts:** 1111

P1252 is a shorted out on/off solenoid for the vacuum reservoir. This can be by-passed, but to clear the CEL you need to buy a new part. Give us a call if you want assistance with the by-pass work around.

4sefed · **Posted:** Sat Dec 18, 2010 3:06 pm

not to revive an old thread but rather than creating a new one

I ran my codes this morning and this is one of the ones that popped up.

just wondering what this part is for and what the deal is if there is a work around, how does it affect the operation of the vehicle?

I got a p0100- I have the maf disconnected
a p0299 I think my frozen ehm issue caused an underboost situation.
and the p1252.

mdalien · **Joined:** Tue Jun 22, 2010 10:22 pm **Posts:** 41

A cheaper fix is a 150 ohm resistor plugged in place of the solenoid.
System thinks the coil is there and is happy.

Quiksilver · **Posted:** Wed Feb 02, 2011 10:02 am

How does this resistor plug in and what does it look like?

Is it wired in or literally plug in? where would i plug/wire it into?

I have bypassed the vacuum line so thats all working again

Dealer wants $100 for the solenoid :shock:

DynoPax · **Posted:** Thu Feb 03, 2011 10:50 am

How typical! I just got that very same code this morning while driving on my way to work... Ordered a new solenoid but was wondering if there is any negative impact with driving the Jeep still. Apart from unsteady throttle, everything else is fine so: Should I stay or should I go?

Quiksilver · **Posted:** Thu Feb 03, 2011 10:58 am

DynoPax wrote:

How typical! I just got that very same code this morning while driving on my way to work... Ordered a new solenoid but was wondering if there is any negative impact with driving the Jeep still. Apart from unsteady throttle, everything else is fine so: Should I stay or should I go?

Do you have a part number - my local guys are just guessing as to which one it is.

DynoPax · **Posted:** Thu Feb 03, 2011 11:44 am

The guy at the stealership also had a hard time finding it and this is what he gave me: 4606226AC

GreenDieselEngineering · **Joined:** Sun Jun 07, 2009 5:10 pm **Posts:** 1111

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.

DynoPax · **Posted:** Thu Feb 03, 2011 3:44 pm

Keith,

Thanks for the swift reply! BTW, if I understand correctly :roll:

, I disconnect it from the solenoid input & plug it into the turbo EVM VAC port.

Reason I'm asking is because I cannot find a %&!* diagram that displays the vacuum system in its whole, apart from the crude one available on moparpartz, lacking details :banghead:

EDIT: Yup, done and working. Now, all I have left to do is pick up the part and install this weekend... Thanks again, Keith!

Quiksilver · **Posted:** Wed Feb 09, 2011 3:56 pm

hey - did you receive the part yet? did it fix it?

DynoPax · **Posted:** Thu Feb 10, 2011 3:42 pm

Yep, installed in a jiffy (2 minutes), hooked the lines back the way they were and problem solved, no more CEL... At least not that kind :furious:

, like the one popping out intermittently because of bad ECM contacts, I presume... Whenever it occurs, it can light up the cluster like a x-mas tree, then leave a couple up (ESP-ABS-Sentry) and shut off the engine after 3 sec. Wiggling the wire pack next to the ECM connector does the trick everytime... Will look more closely into it when the weather gets milder...

BlackLibertyCRD · **Posted:** Sun Feb 27, 2011 2:44 am

Darn it, I now got the P1252. Started out I'm driving in a snow storm about 45 MPH when I noticed the engine surging up and down. I figure maybe it's because I'm plowing through snow so I took it out of overdrive and set the tach steady on 2,000 RPM still about 45 MPH. At one point the esp light flashes kicks it out of gear and throttle down. I recover that and went back to 2,000 RPM and the engine light comes on. Looked at the creader and keeps flashing code P1252. Shut the engine off for a minute at a stop and code came right back. OK if the solenoid for the vacuum reservoir is bad, how did it make the engine surge up and down? I also noticed the headlights blink at times, is this caused by the short, Maybe unplug the solenoid so nothing else gets damaged? I can't tell you if I have a loss of power because I can't get on the throttle in the snow much.

AZ CRD · **Posted:** Sun Feb 27, 2011 11:21 am

BlackLibertyCRD wrote:

Darn it, I now got the P1252. Started out I'm driving in a snow storm about 45 MPH when I noticed the engine surging up and down. I figure maybe it's because I'm plowing through snow so I took it out of overdrive and set the tach steady on 2,000 RPM still about 45 MPH. At one point the esp light flashes kicks it out of gear and throttle down. I recover that and went back to 2,000 RPM and the engine light comes on. Looked at the creader and keeps flashing code P1252. Shut the engine off for a minute at a stop and code came right back. OK if the solenoid for the vacuum reservoir is bad, how did it make the engine surge up and down? I also noticed the headlights blink at times, is this caused by the short, Maybe unplug the solenoid so nothing else gets damaged? I can't tell you if I have a loss of power because I can't get on the throttle in the snow much.

I caught the p1252 a few weeks ago when I power washed the engine bay. My guess is that something got wet in your rig driving in the snow. The loss of power I experienced was fairly subtle--not like a blown turbo hose or anything. Interesting that this code seems to be popping up a lot lately.

I ordered the solenoid, but the short cleared itself before the part arrived.

BlackLibertyCRD · **Posted:** Sun Feb 27, 2011 10:16 pm

OK I switch the vacuum line and unplugged the solenoid. Engine runs fine and now get code P1250 that the solenoid is open instead of shorted. It clears with the creader just like the P0102 code. :mrgreen:

I could leave it like that but I thought I would put dielectric grease in the connector to see if dampness had anything to do with the short. Well the code came right back so it mean the the solenoid if bad. Will order one tomorrow.

JcGilmour · **Posted:** Tue Mar 01, 2011 4:12 pm

I just got into the vacuum reserviour solenoid shorted problem also. Interestingly enough right after I power washed the engine.
I pulled the solenoid and checked its function. It works just fine and the coil resistance is above the minimum 10ohms (26). I suspect this problem is cause by the ECM getting wet and incorrectly measuring the solenoid current.
No fix yet other than bypassing the vacuum around the solenoid and scratching my head.

John

BlackLibertyCRD · **Posted:** Tue Mar 01, 2011 4:53 pm

I got my solenoid today once we figured out the part name for it. It's called Solenoid, secondary runner valve in the parts catalog. :-)r

It fixed the short for me and it hooked back up to normal with no codes.

racertracer · **Posted:** Tue Mar 01, 2011 5:12 pm

Can you tell us where the vacuum reserviour solenoid is located on the vehicle?

JcGilmour · **Posted:** Tue Mar 01, 2011 5:23 pm

Right side of the engine compartment, just above the vacuum reserviour
No hidden at all.

JcGilmour · **Posted:** Wed Mar 02, 2011 11:35 am

For those of you that purchased a new vacuum solenoid because of a p1252 code (shorted) after power washing the engine or heavy water exposure, I suggest that you consider rechecking the old solenoid if you still have it.

As stated in my previous post, I checked mine for a short condition and found the coil resistance to be 26ohms. The manual spec for this is a minimum of 10ohms, so my coil should be just fine and when I applied 12V the vacuum switched just fine.

When I removed the solenoid yesterday to test, I rerouted the vacuum around the solenoid as mentioned in this thread so I could drive the vehicle. I also brought the solenoid in the house and baked it in my toaster oven at 212F (100c) for about an hour. Not that this should have made and difference as the coil resistance was normal but my thinking was that I may have blasted water into the bleed port and this water may have frozen causing the over current (1252) cell.
I reconnected the electrical connector and mounted the solenoid on the vehicle yesterday but the over current condition continued. I left it connected but with the vacuum lines routed around it.

This morning, now about 48hours after soaking the engine with my power washer, the ECM declared the solenoid healthy!

I have reconnected the vacuum lines and all is well.

As previously mentioned, I believe this problem is mis diagnosed by the ECM. I suspect some how after water soaking the engine and ECM, the current measurement to test the solenoid at startup fails for no good reason. Let it dry out (while you wait for the new part) and all is OK.

Best,
J

P1252

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