Hi, I have  Lexus 250 2007 that has done 190,000 kilometres.  I have a trouble code c1241 which i cannot clear, the ABS light is on and the traction control light is on.  I had a mechanic read the codes and he said it comes straight back when cleared.  Based on the code referring to low or high voltage  i have connected by Actron scan tool (which is unable to read the trouble code) and looked at the voltage generated when load is put on the electrics by having air cond on, lights on and demister on.  The voltage varies over time from 14 volts down to as low 12.4 volts but mostly sits between 13.4 and 13.8 volts running the engine at idle and at 2000 rpm.  Even with no electrical load the voltage is as variable as with load.  I am thinking the variability in the voltage, which seems to increase after 5 minutes running is indicating a problem with the alternator. When driving the car the battery light will occasionally come on for short periods of 10 to 20 seconds.  Battery has not been replaced recently but easily turns engine over.  Your assistance is much appreciated.