looking at a 1997 disco engine light is on. And this code comes up=charging system= any idea what it is? Any help would be appreciated. Thanks warren

 

Actually its a 96 thanks warren

 

exactly what code # are you getting ?

 

You will not get a charging system code, if your battery or alt do not have enough juice your battery light on the dash will come on but you wont get a code.

 

P0138 charging system code?

 

P0138.... " o2 sensor circuit high voltage ( bank 1/ sensor 2) "

you likely have a faulty O2 sensor.....driver's side BEHIND the cat converter

the front 02's regulate the fuel /air mix ......the rear O2's basically check the efficiency of the converters....

usually this code ...if it's the only one you have, would indicate a faulty sensor.....you should replace them both( behind the cats) instead of just one.. as you dont want to confuse the Rover Gods,

One way to check would be to switch the 2 rear sensors, side to side, and see if the problem follows the sensor