04' LS no driver heat w/ solution code 2998

[psuguy131]

My driver side heat stuck on high (90) on 12/13/08. No matter what temp I selected it was always hot. Once I turned the car off and back on, the temp went to 60 and stayed there. The passanger side was adjustible.

Using forums like this, I found out how to pull the codes from the heater control unit. I received two codes
1. 1265 cold air bypass valve
2. 2998 Dual climate control valve (DCCV) short to ground

Other posts had these same codes, and I later learned that 1265 can be a kind of "bunk" code that is sometimes thrown out. However, the 2998 was legit.
The DCCV controls hot coolant to the driver (D) and passanger (P) heater core(s). Normally this operates open on high heat (no voltage) and closed on low (60) heat with voltage. The DCCV has 3 ports (from above): D side (right), P side (left), and a supply (bottom).
The P side coolant line was extremely hot to touch under normal operating temps and full heat. The D side was luke warm to the touch (should be hot) and the return line was in between in temp.
The third indicator was the 10 amp fuse was blown. I could replace this for a few minutes of heat, then it would short out again and blow the fuse.

My diagnosis was as follows:
1. Disconnect the connector to the DCCV. This should trigger an immediate full open on both the D and P sides. Once again only the P side was hot.
2. The fuse was also an indicator that there was a short, hence the 2998 code.
3. Upon getting the new DCCV (I recommend Rockauto.com), I blew into the supply port, and both the D and P sides had air flow. No voltage meant that the solenoids were open.

Once I took out the faulty DCCV, I again blew into the supply port. This time I was only able to get air flow from the P side. The D side was closed when it should have been open.
This process took about an hour and a half in a cold garage and a few beers!!! All that was needed was a standard pliers, a large plier, a flathead screwdriver, and an 8mm and 11mm socket. I did not even drain the radiator. I would remove a coolant hose and plug it with clean shopp rags to prevent excessive coolant loss. Note: Leave the bottom supply hose attached to the DCCV you are removing and swap this hose over onto the new DCCV and reinstall together.
Heater control testing followed and this produced correct results. Problem solved.
Parts cost approx. $108.
1 gallon of pre-mex anti-freeze $12 (kind of a jip since non-mixed anti-freeze is the same price, so I'm paying $6 bucks for water).
Total cost with MY labor: about $150 and 3 beers.
Total time: 1.5 hours

I would like to give a very sincere thanks to ShoRod for his support and advice throughout this enitre process. Not only would I recommend his advice to any who seeks it, I would without question take my LS to him in a second.

Any follow-up postings are appreciated.

[gcwimmer]

You may want to bleed the air out of the system a few times.

[shorod]

Thanks for the helpful and detailed write-up!

-Rod