To access and replace the shift solenoid (or the entire valve body which often houses multiple solenoids, as replacing the whole thing is sometimes easier than individually replacing one solenoid), you'll need to:
1. Remove the transmission: This is a major job requiring significant mechanical skills and tools. It's not a simple task and is best left to a professional transmission mechanic or someone very experienced with vehicle repairs.
2. Disassemble the valve body: Once the transmission is out, you'll need to carefully disassemble the valve body. This exposes the internal solenoids, including Solenoid C.
3. Replace the solenoid(s) or valve body: Replace the faulty solenoid C or, more likely, the whole valve body assembly.
In short: The solenoid isn't somewhere easily accessible under the hood. It's *inside* the automatic transmission. You'll need a professional mechanic to diagnose the issue accurately and perform the repair. Attempting this yourself without significant transmission repair experience can lead to further damage.
