ADC auto scan example

Dear,
I also use a XE167FM, I want to read input P15.0 to P15.6 but it's not working.
I change the input at each timer.
When I read only one input it's ok, but if i want to read 15.0, 15.1 the next time... 15.5 the next time it's not working.
I use :

ADC1_vStartParReqChNum(ucCptReadSensor);
ADC1_vSetLoadEvent();
while(ADC1_uwBusy());

fPressureA = (ADC1_uwGetResultData(RESULT_REG_7) + fPressureA * 20)/21;

Do you have an idea about what is wrong?
thank you for your help
Benoît