What is DSTC - 2005 Volvo XC90

has any body suggested running the fault codes first

Raise the vehicle and start the engine. Put the vehicle in drive, make sure that if the vehicle is equipped with DSTC it is turned off. If the front wheels turn but the rear driveshaft doesn't, the most likely cause is the coupler between the transmission and the angle gear is bad.

try a different key, also can try unlocking driver door with key to disable the immobilizer

Dear Sir the Fault you have is all about your Dynamic Stability and Traction Control.The sensors fitted on your wheels which are checking the wheel speed usually get gummed with road dirt and debris and cause error to trigger. Ask Volvo mechanic to clean the sensors and the problem would resolved.

This indicate a problem has occured in the Dynamic Sstability And Traction Control System. You must get the system control module scanned for the fault code. There is a big problem with this system based on the number of complaints seen on line, average cost to repair is about $1000.00

The DSTC system by Volvo means Dynamic Stability & Traction Control, and is the equivalent of the ESP system (means the Electronic Stability Program). If the DSTC lights on the dashboard permanently the DSTC system is faulty. You must access the DSTC Electronic Control Unit (ECU) memory to pull out all DTC (Diagnostic Trouble Codes), using diagnostic equipment connected to the data link connector of the car. Then you will be full informed about bad pieces (e.g.: front right wheel abs sensor interrupted, ...). After bad pieces replacement you will be able to erase all faults memored by DSTC ECU, in other words reset the DSTC system and turn off the warning lamp on dashboard.

what does the yellow triangle means for volvo s60?

Risk for slippery conditions
If the warning light comes on and stays on, this indicates that traction with the road surface is reduced. Drive with caution. If this light flashes, it indicates that the DSTC system is working to restore traction to one or more of the wheels. Reduced Stability Control
If the green indicator light in the DSTC button goes out, DSTC has reduced effect because the system had been switched off with the button in the center console. The text DSTC SPIN CONTROL OFF will be displayed in the text window.

when this code comes up again make sure you get the p code from a scanner to narrow down the source of the problem ,hope this helps,the p code is a more refined direction to where the problem is

Yes they are, you need to run the trouble code test and find out what is stored in memory.