Engine Coolant Bypass Valve Stick

[Moose1269]

Good day,

I own a 2016 Ram Eco Diesel outdoorsman. My check engine light came on and when I used my snap on tool the following codes appeared.
P26AB-00 Engine coolant Bypass Valve Stuck
P2682-00 Engine coolant bypass circuit low

so I purchased an aftermarket Bypass Valve - four Season #74916

i removed the factory three way coolant valve and installed
The aftermarket Four Seasons Valve. The plug would not line up with the plastic fins on the Four Seasons assembly so I used a utility knife to cut them off so I could attach the plug to the valve body. So everything appears
To be working, I have good heat and AC when I alter
The temperature from high to low. But the engine codes are back. I tried clearing them several times with no luck. Am I missing something, maybe as it was not quite plug and play perhaps the ECM is picking up a
Voltage difference causing the code?
Any suggestions would be greatly appreciated. Below is the old valve and the box that the aftermarket valve came in.
thanks for
Any help in advance.
Matt

 

[Tmckinney20]

Matt, years ago I ran into a similar problem on a mercury. I bought a second rate knock off verses an OEM bypass valve trying to save a few bucks. My codes kept coming back. I bought an OEM valve and everything cleared up with no further issues. I'm not saying it will fix your issue, but some things I would replace with a factory part. Others like belts, hoses, oil you can get away with. If the price difference is minimum, choose an OEM part. It could save you money and headache long term. Sorry I could not help you further but I thought I would pass on my experiences.

 

[Moose1269]

Matt, years ago I ran into a similar problem on a mercury. I bought a second rate knock off verses an OEM bypass valve trying to save a few bucks. My codes kept coming back. I bought an OEM valve and everything cleared up with no further issues. I'm not saying it will fix your issue, but some things I would replace with a factory part. Others like belts, hoses, oil you can get away with. If the price difference is minimum, choose an OEM part. It could save you money and headache long term. Sorry I could not help you further but I thought I would pass on my experiences.

I ordered the Mopar factory replacement valve this morning. I will have it by June 27th and installed shortly after. I will make sure
To post the results either way.
it was 270 total vs 444 total for the OEM part. A bit of a difference but for the extra 174.00 dollars I would trade up any day for the headaches. I was stuck on a Sunday with the new valve already installed otherwise I would have just returned it when the electrical plug wasn't an exact plug and play.
Ill be back with the results by months end!

 

[Tmckinney20]

Here is where I buy my Mopar parts.

2014-2019 Ram Coolant 3 Way Valve 52014971AB | My Mopar Parts

2014-2019 Ram part # 52014971AB - Coolant 3 Way Valve

www.mymoparparts.com

 

[Moose1269]

Yes thats the US website and pricing, wish our price was similar up here in Canada. The canadian Mopar.ca is roughly 100.00 Canadian more than that US price.

2015-2019 Ram HVAC Heater Control Valve 52014971AB | Mopar Parts Canada

HVAC Heater Control Valve - 52014971ab. Genuine Mopar® Parts & Accessories. Manufacturer Warranty. From the Dealership to your Door.

www.moparpartscanada.ca

 

[Moose1269]

Yes thats the US website and pricing, wish our price was similar up here in Canada. The canadian Mopar.ca is roughly 100.00 Canadian more than that US price.

2015-2019 Ram HVAC Heater Control Valve 52014971AB | Mopar Parts Canada

HVAC Heater Control Valve - 52014971ab. Genuine Mopar® Parts & Accessories. Manufacturer Warranty. From the Dealership to your Door.

www.moparpartscanada.ca

Update on the 3 way Coolant Valve. Just as a recap I replaced the original factory 3 way coolant valve with an aftermarket Four Seasons 3 way valve.
the tabs on the Four Season 3 way valve electrical port were not spaced to match the Ram electrical connector so I had to cut them off. Need less to say the fault codes would not clear with this aftermarket valve. I replaced it with the Mopar factory recommended 3 way valve and problem solved. i returned the four seasons Piece of garbage for a full refund. Hope this helps saves someone some time down the road!!

 

[Moose1269]

Running into the 3 way coolant Valave issues again. Trouble code indicates valve stuck.
i unplugged the 6 wire plug from the valve body and tested terminal 1 and it has no supply voltage when it should be 12vdc with ignition in run position or truck running. I trace the wires to a ten pin connector just inside the bumper passenger side. Unplugged it, cleaned it and tested the supply wire pin feeding it and nothing there as well. The wires are tapped up and they go up into a larger wrapped bundle at the front top passengers side rail.
they go back to the wire conduit and some appear to the ECM. I didn't unwrap the bundle
Yet but just checking to see if anyone knows where the supply termination is?

thanks again,
Matt

 

[559ram]

Following Ive had a similar issue I keep getting bypass codes even after replacing with mopar part it worked for awhile then same as you codes came back took it to dealer they claimed plug by bumper was corroded and quoted 1k to repair it I said no way and checked plug i do not see any corrosion I did clean it and add dialetric grease I do hear a clicking which Im assuming is the bypass valve trying to move when i cold start the truck Im at a lose also

 

[Moose1269]

Sorry this has taken a bit of time. Just juggling family and work then in trying to trouble shoot this issue. So as a recap, 2016 Ram eco diesel. I
Changed the 3 way coolant valve in June 2023 replaced with mopar coolant valve. In November 2023 the Service 4WD light came on intermittent, then stayed on solid. With in minutes the check engine light came on. i read the code and is was P26ab 3 way coolant valve stuck.
i tested power to the coolant valve on pin 1 of the connector and supply was 0 volts DC with ignition in run position engine off. i disconnected the 4 pin connecter to my front Differential 4WD actuator and tested for supply and had 0 volts DC with ignition in run position.
I traced the wires to the 10 pin connector just inside the front passengers side bumper and disconnected it. I tested power on the pink and beige pin and 0 Volts DC. Today I disconnected the 10 pin connector and pulled the bundle of wires up so I could unwrap the black tape and inspect the wires. Low and behold the tape was worn through and the pink and beige supply wire was severed. The ground was barked up a bit as well. It rubbed through on the metal frame but without taking the bundle up to inspect you would never be able to see it. I reconnected the wires and used heat shrink to seal the connection up. Taped everything and tucked it all back in. 4WD Service light went off immediately and I cleared the engine code and all is back to normal!! Hope this helps someone else out in the future. Power to the 3 way coolant valve is also power to your 4WD actuator.

 

[1shadowsabre]

That is some good troubleshooting Moose, nice job!

 

[nschlomer]

Hi everyone I'm having the same issue with pending code coming up shortly after first start. The cel will come on after second start. All this after checking harness and replacing valve with oem. I'll check the power wire next but does anyone have a pinout of the connector? It's a 2014 btw.

 

[Moose1269]

Here are the Pin out descriptions for the 6 pin connector that plugs into the 3 way coolant valve. Clean the wires off good so you can See the colours, you will find them back at the 10 pin connector. If there is an open or short in Supply (12vdc) from
The 10 pin connector then the 4 wheel drive Service light should come on as well…..only if you have 4wheel drive. If no power at the 10 pin connector with ignition in the on position then check your fuse next. If fuse is good go back to that 10 pin connector and start peeling back the tape to inspect the wires. Its a pain in the u know what but it the only way that I could figure out my issue.

 

[nschlomer]

Thank you for your response it is appreciated! I checked the connector at the valve and a good 12v supply, good 5v supply, ground is good, 3.18v on the signal supply when I start the truck with heat on. I have 1.8v on the signal supply when I start the truck on cold. I even hooked up my old valve that threw the same codes and it would switch between cabin heat and trans heat. The only thing I suspect is the signal return voltage does not change at 11mv when the valve is in either position. Does anyone know what that voltage should be? I assume it would be different at closed and open positions.

 

[Mar]

Matt, years ago I ran into a similar problem on a mercury. I bought a second rate knock off verses an OEM bypass valve trying to save a few bucks. My codes kept coming back. I bought an OEM valve and everything cleared up with no further issues. I'm not saying it will fix your issue, but some things I would replace with a factory part. Others like belts, hoses, oil you can get away with. If the price difference is minimum, choose an OEM part. It could save you money and headache long term. Sorry I could not help you further but I thought I would pass on my experiences.

I agree, lots of knockoffs out there that I have read failing. Spend the extra and do it once. I did, no issues.

 

[markb]

Moose1269- you just saved me a bunch of money and time. I had the exact same problem. First the Service 4WD light came on, 45 minutes later the check engine and the P26AB code. Found your thread and located shorted out wires on the same 10 line wire harness behind the passenger side bumper. Looks like the harness gets stuck between the wheel well cover and the frame and then rubs through the wrap and insulation. Don't know if I would have ever found this, let alone in less than 2 minutes under the hood!

 

[rickram]

Moose1269- you just saved me a bunch of money and time. I had the exact same problem. First the Service 4WD light came on, 45 minutes later the check engine and the P26AB code. Found your thread and located shorted out wires on the same 10 line wire harness behind the passenger side bumper. Looks like the harness gets stuck between the wheel well cover and the frame and then rubs through the wrap and insulation. Don't know if I would have ever found this, let alone in less than 2 minutes under the hood!

I'm working on a 14 with a hemi. Spent the 500 on a new valve. Seemed like everything was heating up correctly.
Had burn your face off heat last night.
Today blowing outside air .I came across this thread a couple of days ago.
Had the truck running up to temp. Not blowing heat.
Went under the hood and jiggled that 10 pin plug around.
Went directly to the cab and it was blowing burn your face off heat again within seconds.
Had to search the Googles to refind this thread.
The valve that was in there had been replaced had a 2016 date on it.
This has put me in limp mode a couple of times. Due to a cooling performance code.
Feeling confident and hopeful I'll find the bad spot tomorrow.