Error Code P085C is defined as Gear Shift Control Module “B” Communication Circuit High. Error Code P085C is a generic trouble code, meaning it applies to all cars with the OBD-II system, especially those made from 1996 up to the present. Specifications on the definition, troubleshooting, and repairs, of course, vary between make, model, and powertrain configuration.
The PCM (powertrain control module, also known as ECM or engine control module) monitors the gear shift control module. It sets the error code if it sees a problem communicating with the gear shift control module, particularly if the data sent to the PCM is lower than the expected or the specifications set by the manufacturer.
Check Engine light or Service Engine Soon Warning light on.
Check for the possible causes listed above; inspect all related wirings, connectors, and harness.
Then, check for damaged components such as bent, broken, pushed out, and corroded connector pins.
Make sure you test drive your 2012 Mitsubishi Eclipse spyder after completing any repairs to see if the condition is fixed.
Don’t forget to erase all P code(s) first before taking your 2012 Mitsubishi Eclipse spyder for a test drive. This will turn the Check Engine light off, which will give you a good idea if your repairs worked as the Check Engine light will be activated if the problem remains.
This is a serious and complicated problem, which means it must be addressed by an expert technician as soon as possible.