It is well known that a number of modern cars can be very unforgiving of low battery charge conditions. The NG 9-5 is, apparently, not exempt from this problem.
One reason for the system to generate fault messages is high resistance in sensors and load components, motors, solenoids and lamps. While doing a routine check round the engine i decided to check the earth points, these are located around the front strut top mounts and on the bodywork between the radiator and the headlights. I also checked the battery earth connection.
Contrary to popular belief the battery terminals should be absolutely free of any contamination during assembly. By all means apply a thin film of suitable grease after assembly. The quoted torque value for the battery terminal bolts is 4.5 nM not 20nM both terminals were well below the WIS figure when I started.
Earth points similarly should be free of all contaminants when assembled, I disconnected one to find that this wasn't the case so I cleaned the earth point, ring terminal and nut before tightening it, I used 15nM. I checked all the other earth points and found the torque to be well below this figure.
Whether you are suffering from spurious fault messages or not, I would urge all NG9-5 owners to check the tightness of all the earth points and the battery terminals.
