Code P1113

P1113 on a GM/Vauxhall/Holden is usually a damaged or failing intake port resonance valve position sensor. Basically the sensor which tells the PCM what location the vanes in the intake for the dual port system are in is failing or has failed. From what I have read about it you will probably need to replace the intake manifold as the sensor is not a replaceable part.

Low voltage air temperature issue

I do not have a listing for that fault code, so I can only offer some generalizations. Temperature sensors are very simple two-terminal sensors with just a single component inside. For that reason, failures are very uncommon. Many cars have the intake air temperature sensor built into their mass air flow sensors. Those will have many more wires, but the sensor operates the same way. You are just as likely to find an individual sensor in the fresh air tube leading to the throttle body.

Most fault codes set as a result of a wiring problem to that sensor. 5.0 volts is fed to the sensor, and it gets drawn down by it to somewhere between 0.5 to 4.5 volts. That is the acceptable range of signal voltage for this type of sensor and many other types. Anything outside that range is what triggers a fault code. Anything that causes a break in the circuit will result in 5.0 appearing on the signal wire, and that is not an acceptable voltage. A cut wire or an unplugged sensor will set the code, "sensor voltage too high".

It is less common to get a code for "sensor voltage too low". That is typically caused by the signal wire being rubbed through and shorting to ground, meaning the engine or body sheet metal. It will also be set if the signal wire is purposely grounded to see if the computer responds appropriately and "sees" the intended change in voltage. A less-common cause is the terminals in the sensor's connector are bent over and touching, or there is corrosion growing between those two terminals.