The driving rod position sensor for a 2012 Chevy Impala will be situated in the engine of the vehicle. You'll have to look behind and the motor and close to the firewall. It will be on the lower left hand side of the motor among it and the firewall. A substitution sensor will cost somewhere in the range of $20 and $50. The higher of this will be for an OEM sensor. If you have any desire to have an expert trade out the sensor for you it will cost somewhere in the range of $150 and $300 for all out parts and work.