Yading and Yarchen Gar

Thanks all. Just one last question. Is it a risk, weather wise, to go around September 10 to 18? Or, will the rain likely still be coming down?

kxpn, many thanks for helpful information.
Re 3. 雅康高速, I wanted know if time between Kangding and Changdu by bus would be much shorter than now(abt 7hrs).
Now I'm thinking to rtake following itinerary:-
1. basis Sertar and Larung Gar are opened and able to buy direct bus ticket to Larung Gar/Setar:
Chengdu- Larung Gar-Ganzi-Yarchen-Ganzi-Danba-Siguniang shan-Dujiangyan-CTU
2. Oterwise:
CTU-Dujiangyan-Siguniang shan-Danba-Ganzi-Yarchen-GanziKangding or Dujiangyan-CTU
(also for altitude acclimatization)

@mattweisbard,
September is at the end of rain season, still high chance to rain, but shouldn't be too bad. Sometimes rain in the lower place but sunny in higher altitude area, or vice versa, hard to predict.

@sakakitakahiro,
A good news about Sertar, it's open, reportedly some Taiwanese and Korean have been visited their recently.
I don't know which road buses would take, expressway or G318.
It's not easy to make a 100% accurate travel plan for that region, for example the road is under construction when you are there, or temporarily close due to bad weather on a high mountain pass, or you are very unlucky stopped by police for entering Sertar...
I would recommend you do the difficult part first, leave the easy part to the end. Like: take a direct bus from Chengdu to Sertar, after Sertar going to Ganzi and Yarchen, and then Danba, Siguniang shan, Dujiangyan on the way back.
According to internet, minibus from Sertar to Ganzi (甘孜) take about 5.5 hours, from Ganzi to Yarchen Gar time is almost the same. In Ganzi, minibus to Yarchen Gar (寺廟班車) is at around intersection (川藏路/東大街).

@kxpn,
Whao! That's really good news.

Did Taiwanese and Korean travelers visited Setar with public transportation? or just managed to avoid check point on the way?

It would be helpful if you could advise where you heard such informaion from and kindly advise if it's from web site.

Yes, I will go Larung Gar first with direct bus (12-14hrs) if officially opened for foergin travelers and able to purchase bus ticket to there as it's much easier.
Thanks for useful information for local transportation in eastern Tibet!

It's mentioned in a post written by Taiwanese who visited there one month ago, he/she said the hotel staff told them two Koreans were stayed there a couple of days before them. See the last post (post #5) from the thread below:
https://www.backpackers.com.tw/forum/showthread.php?t=1925799#post10479311

Even if you can manage to avoid the checkpoint, you probably can't find any place to stay. No hotel will willing to let you stay cause they may face serious consequence.
The checkpoint is in Wengda near the main road G317, so if you are in very bad luck stopped by police, you can catch another car/bus keep going to Ganzi, having a contingency plan is always a good idea.

From the thread above you can also find a facebook link that owned by car rental people based in Chengdu, I suppose they can understand English, try to contact them see if you can get more up-to-day information:
https://www.facebook.com/rentalcar88

@kxpn,
Thanks for the above.
My understanding is correct for the first and last part?
6/30 They took the Bus to Sertar which left Chengdu 06:45 and ticket inspector took photo.
7/1 Hotel reception told that two Korean travelers stayed few days ago
But I could not translate properly middle part of post especially

"公安揮揮手說不必，約6:00到學院山腳下，坐公交上山"
What happened at Wengda check point? Police officer allowed them to enter Larung Gar?
Or they went Larung Gar by themselve from Wengda next day though police officer stoped them?

我們6/30坐6:45往色達的大巴，過檢票口，見檢票員有多一個動作，照相。
過翁達檢查站司機叫我們下來，公安揮揮手說不必，約6:00到學院山腳下，
坐公交上山，住喇榮賓館。
7/1到縣城，青旅前台告知有兩個韓國人前幾天也進來了

I'll translate the relevant part, if you don't mind:

"When we went through the Wengda checkpoint, the driver asked us to get off the bus, but the officer at the checkpoint waved his hand and said that it wasn't necessary [for us to get off the bus]. About 6:00, we arrived at the foot of Xueyuan (College) mountain. We took a bus up the mountain, and stayed at the La Rong Hotel."

@Giora
Many thanks for your helpful assistance.
It's still unclear whether Setar and Larung Gar officially opened for foergin travelers and how they purchased bus ticket.
However hope this is good news for foergin travelers.

I also hope for good news on Larung. If it's open for foreigners I hope to revisit Larung in October.

Wengda is 80+ km before Sertar, I believe if you can pass the checkpoint in Wengda that means you are allowed to enter.

Sorry I can't confirm that news. Just bear in mind that even it's official doesn't mean much, things can change at anytime for any reason. (for example if someone do something that might cause tension, they will close the road immediately)
So, take your chances, plan for the worst, hope for the best, enjoy an adventure journey...