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Discussion Starter · #1 ·
Hi everyone!

I had the issue where heat won't come out unless the ICE was running and troubleshooting points me to replacing the 2-way coolant valve (PN# 22987494).

I've checked around the forums and Google and people mention replacing it, but I can't find any how to. The closest thing I can find is the to replace the pump in the passenger wheel well, but that's (possibly) not the problem.

Can someone point me to where I can find the right steps for this valve please?

Thanks!
 

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according to the service manual,

Preliminary Procedures
1. Disable high voltage system. Refer to High Voltage Disabling and High Voltage Enabling .
2. Pinch and remove the heater water shutoff valve actuator inlet hose from valve. Refer to Heater Water Shutoff Valve Actuator Inlet Hose Replacement .
3. Pinch and remove the heater water shutoff valve inlet hose from valve. Refer to Heater Water Shutoff Valve Inlet Hose Replacement .
4. Pinch and remove the heater water auxiliary pump inlet hose from valve. Refer to Heater Water Auxiliary Pump Inlet Hose Replacement .
 

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Thank you so much!! I don't suppose you would be willing to share the steps for disabling the high voltage system as well, by chance? ��
1. First disconnect the 12V AGM battery by removing the negative lead and setting it aside.
2. Open the center console and remove the bottom covering. Remove the HV disconnect plug.

When you are done, reverse the procedure. Connect the HV disconnect plug first, then reconnect the 12V battery.
 

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Discussion Starter · #7 ·
I figured out how to remove the quick connect! It's held in place with a U shaped thin metal clip. Get a flathead screwdriver wedged into the top end of the little clip and push it off then simply wiggle and jiggle the hose off.

Now onto the next problem: I replaced the valve and the heat still isn't working in EV mode! Ughhhhh.... No more CEL though, that's nice! (Hopefully it's not just because I disconnected power like normal cars do)

I did a ton of research over the year and people tested various ways and outcomes of turning heat on full blast in comfort on HI. My power consumption would go to about 5kw for about 10 seconds then slowly go down to 0.5kw. Many people on the forums found it was this valve causing the problem as it was stuck in ICE mode. This time my power went up to about 7kw for about 1 minute and very slowly dipped down to 0.5kw.

Any ideas?
 

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If it is not the valve or the pumps and you have checked the fuses, it is probably the Coolant Heater Control Module (CHCM). This is the electric unit that creates cabin heat when the engine is not running. It is prone to failure. I just had mine replaced. In Canada, it was a $900 part and $900 labor plus diagnostics. I think the unit will throw a B101D diagnostics code (or something similar to that) but not necessarily a check engine light. There is a service bulletin on it ( https://static.nhtsa.gov/odi/tsbs/2013/SB-10063994-2273.pdf ) which may or may not apply.

There is a youtube video ( https://www.youtube.com/watch?v=NgJM6vpHGQE ) on how to diy it if you are so inclined and the part can be had online for less than $900 Canadian. To access the part to remove and replace it, remove the top intake cover, disconnect the fuel injectors, disconnect the fuel rail, remove the intake manifold in order to have the clearance, clamp the lines, remove and replace and then put it back together and top off coolant. Lots of hoses in the way and very little space but doable if you have the tools and are in reasonable shape (you pretty much have to lay on the engine/fender to get in to do it. You may need access from underneath too to undo the clamps.

Of course, you also need to disconnect the 12v and the disable the hi-voltage battery as it is a high voltage part.

So far, I have not been able to get it covered under any warranty. Some here suggest it is a voltec part but the dealer and the service guide say otherwise.
 

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Did you rule out the pump being the problem? If you are going to throw parts at this, that is probably the next step. The question is which pump and where is it. I think there is more than one pump in this circuit.
 

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Discussion Starter · #11 ·
I'm thinking a pump might be the next step. There used to be a thread where they mentioned the name and part# buy I can't seem to locate it anymore. It was in the right front passenger wheel well and I think it was called a heater coolant pump?

Any help locating that part number would be great, thanks!
 

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Discussion Starter · #12 ·
Good news! I replaced the heat coolant pump today and my heat is back to blasting HOT!!! It was WAY easier than replacing the 3 way valve too!

Spent a total of just under $250 between both parts.
 

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My 2014 had similar symptoms... no heat unless I ran the engine in hold mode and then later the heat would work ...sometimes for a day or two. Also at times the pump was making a bad vibration that could be heard and felt thru the firewall at the passenger foot level. Got into the dealer this week and the diagnosis was the heater control module had the error code and identified with an intermittent short .... scheduled replacement in less than 2 weeks (due to holidays) and glad I purchased extended GMPP which is covering cost.
 
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