Code PO243 - Wastegate solenoid

[Halbur]

I've had the check engine light on twice in the last week. It went out on it's own once but is back now. Code PO243 for the wastegate solenoid is coming up. The truck is running normal and if it wasn't for the light I wouldn't know a thing. I have two questions. Can I run the truck normaly (light duty) until the new solenoid gets here? Also, when I checked the fuse as some other forums suggested (#6) the slot was empty! Any help is appreciated.



2006-2500-no mods.

 

[p-Bar]

It should be fuse 36 if memory serves me right. You will go into limp mode no A/C low boost

 

[cerberusiam]

The solenoid is controlled directly form the ECU, no fuse. You can drive around for years with the CEL and have no problems other than it won't make more than 25 lbs of boost. To solve that just crimp the boost reference h0se and go easy with the right foot.

The solenoid has failed and defaults to full boost. For about $60 you can get a fooler and a boost elbow to disable it and turn the CEL off.

 

[CKelley1]

the solenoid failure results in 20 psi max boost. the boost fooler will not do anything. nearly 100% of the solenoid failures is a broken wire about 1/4 inch away from the solenoid. unplug it and with a pair of water pump pliers unscrew it. flex the wires to determine the broke one and repair. p0243 code is set off on high ohm's on solenoid, not on boost pressure. a better way is to get a 147 ohm 1 watt resistor and cut the leads off of the solenoid and use the resistor instead. next add spring tension to the diaphragm to increase opening to 33 psi. look at a bd spring kit to see how to fashion one or buy theres or get there adjustable diaphragm. it is easy to adjust either one with the turbo on the bench. just hook the diaphragm up to your paint spray regulator and adjust opening to 33 psi, reconnect hose and install. i was born lazy and convert the solenoid to a adjustable boost elbow. it takes me 30 minutes to convert and 10 minutes to adjust without removing turbo or need of air to adjust. but i have a lathe and well equipped shop. here is a pix showing where the wires broke on this one, we pick up bad ones to convert saving our good ones for others. i am out of good ones for the moment. #ad

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[DNDracing]

The failure on the truck pictured in my avatar and in my signature was exactly what ckelley described, broken wire just down loom from the solenoid. Unfortunately my poor trouble shooting skills didn't realized this before I replaced the solenoid. New solenoid had a 2" pig tail that also fixed the break.

I did drive around with the CEL on for about a month before I got to the fix with no issues.

Check the wire connections first. If you can't find anything there, and it is the solenoid valve, this is where I got mine:

http://hoeslidiesel.com/store/page13.html

 

[cerberusiam]

Just to clear up some misinformation, the PO243 can be set for any number of reasons. Broken wire, shorted wires, or a failure in the solenoid itself. The control signal is a PWM signal and if it doesn't work right or looks wrong to the ECU it sets a CEL and the solenoid goes full open. Default full open is full boost to the WG actuator which, depending on how it was set, usually is 22-25 psi. Enough to make the truck run decent but not over boost it and go into limp mode. The failures are pretty even between a solenoid failure or a simple broken wire.

A boost fooler was not mentioned, a boost elbow was and is the simple fix along with a WG fooler. Once the solenoid fails you treat it just like an HX35 and add an elbow to control boost to the actuator. The WG fooler is just a resistor to turn off the CEL. It can be bought or built depending on preference.

 

[CKelley1]

cerberusiam we are probably saying the same thing only in a different form. the wg fooler is the resistor i mentioned. the ecm sends a 5 volt pulse modulated width signal to the solenoid. the solenoid's purpose is for emissions control, it works as part of the in-cylinder egr. with no signal to the solenoid a set of passages is blocked off by a spring loaded tip. the speck calls for it to be 20 psi gate opening. the diaphragm is set for 20 psi at this point the pressure and temp is not high enough to produce a lot of NO as engine load increases the ecm will try to limit the boost to just barely have enough oxygen for combustion thus no excess oxygen to produce NO. it works this way, as the ecm sees need for more air it sends wider and more pulses to the solenoid opening the ports to relieve some pressure back to the volute, thus raising boost under very tight control. the dimensions of the he351 has more back pressure than i like at high end to trap the exhaust in the cylinder for the egr. if you look at the curves on the 351 about the max efficiency is around 32 psi and is down hill from there. we run a fleet of dodges and did many test to figure out how to delete the egr, we watched the solenoid signal on a oscilloscope while driving. i have never shorted the wires out for fear of ecm damage but when trying to determine the size of the resistor i could use before setting off the p0243 code i can tell you it is the resistance that sets it off. in dismantling the solenoid it is obvious that a failure internal to the solenoid would be no more than 1 in a 1,000 failures. the high resistance will come from the break of the wire or a bad crimp on the wire plug. we removed our solenoids and modified them as the trucks came from the factory. halbur it only takes 2 minutes to remove it to look at it, grab it anywhere with the pliers and unscrew it. you will find the problem immediately. if you put a new one on keep that one for a potential future mod.

 

[cerberusiam]

The ECU montors resistance as a default. A short or open will trigger an error. It also monitors rationality of the signal. If the solenoid fails to set correctly based on what the ECU wants to see it defaults it to open and sets DTC's. The last 3 I did in additon to mine were a solenoid failure. Futz with them enough and they would work for a time then code again.

All the solenoid does is control the amount of boost that is applied to the WG actuator, DP has nothing to do with it. The ECU has a set point it tries to maintain boost at to limit fueling and emissions. When it cannot maintain boost with a rational range it codes and sets a CEL.

 

[CKelley1]

it does not monitor the rationality of the pmw signal, for the p0243 code the ecm sends a siglal to the solenoid to tightly control it but if it does not it will not set off a p0243 code. the p0243 code is resistance only. proof is when you add a aftermarket turbo and the resistor you never set off a p0243 code no matter where boost or fueling is at. the wg actuator is set at 20 psi opening the solenoid is a adjustable boost elbow that is adjusted by a 5 volt pwm signal from the ecm. in your failures the wire was into inside the insulation and did not look broke.

 

[cerberusiam]

Oh, it does a bit more than monitor resistance. The WG controller is a solenoid itself that can short to ground or draw too much voltage and trip the code for rationality. The driver circuit in the ECU is also monitored to make sure it is not shorted or open. The resistor replaces the solenoid which is the biggest error generator so of course you get no codes goven the harness and ECI is good. The P0243 is catch all code that means there is a problem in the circuit, that is why there is 8 steps to determine where the issue is and what the fix is.

I have had this code generate randomly with an over boost code and stock software WITH the resistor in place and working. I have had it show as a DTC and no CEL, and with a CEL and 10 other codes when a battery\ground issue was present. The circuit failure can also be a part of other circuit failures and DTC's. It is not JUST resistance.

DAMAGED WIRING HARNESS OR CONNECTORS
WASTEGATE SOLENOID
(F504) FUSED IGNITION SWITCH OUTPUT OPEN
(K139) WASTEGATE SOLENOID DRIVER CIRCUIT OPEN
(K139) WASTEGATE SOLENOID CIRCUIT SHORTED TO GROUND
(K139) WASTEGATE SOLENOID DRIVER SHORTED TO VOLTAGE
(K139) WASTEGATE SOLENOID DRIVER CIRCUIT SHORTED TO ANOTHER CIRCUIT
ECM
INTERMITTENT CONDITION

6. (K139) WASTEGATE SOLENOID DRIVER SHORTED TO VOLTAGE
Measure the voltage between the (K139) Wastegate Solenoid driver
circuit at the Wastegate Solenoid connector and battery negative.
Is the voltage less than 1 volt?

8. WASTEGATE SOLENOID
Reconnect the ECM harness connector.
Reconnect the disconnected Wastegate Solenoid harness connector.
Turn the Ignition on, engine not running.
Disconnect the Wastegate Solenoid harness connector.
Connect an incandescent test light across the supply and driver pins
at the Wastegate Solenoid harness connector.
NOTE: The ECM will perform a self check of the circuit after
approximately 30 seconds, which should light the incandescent
test light.
Does the light illuminate brightly after 30 seconds of being connected?

 

[MChrist]

Hey, guys. My truck just gave me a CEL with code P0243. My compound turbo system actually removes the solenoid and plugs it, and I have a boost fooler wired in. No problems since I installed the system several years ago. Any idea where I should start looking, since I don't even have a solenoid? I already gave her a thorough looking over for bare wires and found none.
I've cleared the code several times, but it returns within a few minutes.

Thanks!

 

[cerberusiam]

The WG fooler has likely failed. They do that occasionally.

 

[MChrist]

Ok thanks. I'll order a new one and see if that fixes it. Otherwise, truck runs and acts exactly the same as before.

 

[MChrist]

The WG fooler has likely failed. They do that occasionally.

Cerb, I thought you would like an update. I called ATS and ordered a new boost fooler. The gentleman also suggested the solenoid cap off thing. . don't remember what it's called. . but it's by the oil filter and connects the two wires that went to the waste gate solenoid. It was only $20, so what the heck.
The new boost fooler is all built into a 8" piggy back whip, so you unplug the weather pack plug from the sensor (MAP?) and plug this in its place, then plug the original into the new whip. The old one was spliced into one of the wires, so that needed to be respliced using solder and heat shrink.
That didn't fix it. I cleared the code, but it returned after a few seconds. Well, I still had that other part, so I popped that one in, and that cured it!!
I took pictures of everything, but the cap off thing had corrosion in it. It's a weather pack looking thing, but the open end is sealed with shrink wrap, so salt and water had worked its way in and completely powdered the connecting wires!!
Check engine light is now clear. Hopefully, this may help others. Check your solenoid cap off thingy for corrosion. It's right in front of the oil filter, and easy to get to. And only about $20. Mine was sent to me by something like "Big O" or "Rock Auto". Same place, two names.
Either way, hope this helps. And thanks, Cerb for pointing me in the right direction.

 

[cerberusiam]

The WG fooler has likely failed. They do that occasionally.

Mchrist, notice I said WG fooler, that would be the one by the oil filter, not boost fooler. Your asessement of the corrosion causing the problem is dead on. If the WG fooler does not pass the signal correctly the code pops up becuase the ECU thinks the circuit is open. When I get those codes I umplug, clean, and use dielectic grease on the boost and WG fooler and the problem usually disappears.

Glad you got it fixed.

 

[MChrist]

DANG, you are absolutely right!! My eyes saw WG Fooler, and my brain saw Boost Fooler. . If that's the only mistake I make today, I'll be happy :-laf



Thanks again.

 

[fantom318]

After having the p0234 code come on and off in my 07 5.9 dually a few times, I did some searching on the web and ended up finding this post. After reading everything and finally getting some time to look over my truck, I cleaned a few electrical connectors, I crawled under the truck to examine the wiring on the wastegate solonoid and low and behold when I looked up at it, there was a spot of green on the one wire about 2" from the connetor. Cut it out and spliced it back together, drove the truck for 30 some miles and cel never came back on. Great place for very useful information.

 

[Jack in Alaska]

My RAM has been coding P0243 for a month, on and off then on, then off. Truck runs fine, 40psi boost etc. After researching I found an article about the wiring bundle rubbing on the tiny wires to the waste gate valve. Upon further inspection my truck has suffered from the same fate. Fortunately I had ordered a new waste gate valve, pricey little sucker. We installed it today and all is well once gain in RAM land. Way cheaper than a truck payment.