LGT CREW HAD TCASII RA.

Narrative

ON APCH TO SJC; ILS RWY 12R; DOWNWIND LEG; IMC CONDITIONS; BAY APCH TOLD US TO TURN R TO 100 DEG HDG TO INTERCEPT THE LOC AND CLRED US FOR THE ILS RWY 12R AT 2000 FT; SJC. AFTER ROLLING OUT ON THE INTERCEPT HEADING; THE GS HAD ALREADY CTRED AND THEN SHOWED US HIGH. A MOMENT LATER; WE HAD A FULL GS DEFLECTION WITH NO LOC CASE BREAK. WE RECEIVED A POOR VECTOR FOR THE APCH AND WE WERE LESS THAN 6 MI FROM SJC; SO I TOLD MY FO TO REQUEST A MISSED APCH. SJC TWR INSTRUCTED US TO FLY RWY HEADING AND MAINTAIN 2000 FT. A MOMENT LATER; SJC TWR INSTRUCTED US TO CLB AND MAINTAIN 3000 FT. WE CLBED TO 3000 FT WHILE COMPLETING THE GAR ITEMS. RIGHT AFTER LEVELING AT 3000 FT; MY TCASII AURAL VOICE SAID 'DSND; DSND; DSND.' I LOOKED AT THE TCASII SCREEN AND IT INDICATED A MANDATORY 2000-2500 FPM DSCNT IMMEDIATELY. I ALSO SAW THE TARGET ON THE TCASII SCREEN RIGHT NEXT TO OUR PLANE AT 9 O'CLOCK POS; VERY CLOSE PROX (+100 FT) 6 MI SCALE. WE WERE STILL IMC. I IMMEDIATELY PUSHED THE NOSE DOWN AND DSNDED TO 2000 FT. MY FO TOLD THE TWR WE EXECUTED A TCASII DSCNT. TWR THEN TOLD US TO MAINTAIN 2000 FT AND SWITCHED US BACK TO APCH CTL FOR ANOTHER APCH/VECTOR. THERE WERE NO FURTHER PROBS. AFTER LNDG SJC; I CALLED BAY APCH/SJC TWR ON THE PHONE AND THE BAY APCH SUPVR APOLOGIZED FOR ISSUING OUR CLRNC TO 3000 FT (RELAYED BY SJC TWR). HE INDICATED THERE WAS A MISCOM BTWN THE CTLRS SOMEWHERE IN THE CHAIN OF EVENTS.