B737 Undifferentiated or Other Model
Flight Crew Air Transport Pilot (ATP)
Flight Crew Last 90 Days 169; Flight Crew Type 16700
Situational Awareness; Human-Machine Interface
Deviation / Discrepancy - Procedural Published Material / Policy
Air Traffic Control Issued New Clearance; Air Traffic Control Issued Advisory / Alert; Flight Crew Became Reoriented; Flight Crew Overcame Equipment Problem
Human Factors
Received ATIS for SJC which stated to expect ILS 30L Approach.  Programmed FMC based on that criteria and completed a thorough brief.  As with all briefs; as Pilot Flying; I read from the approach plate and STAR plate while Pilot Monitoring verified the FMC.  Unknown to me; the First Officer (FO) had inadvertently selected a transition point of GILRO which does not exist on this particular STAR (SILCN 1).  He said he noted that he had done that as I was briefing and he was going to 'clean it up'; however; we were given a descend via with a modification of deleting the restrictions at waypoint VLLEY of 280 knots/FL 190-FL 140.   This left us with nothing but at or above crossing restrictions on the rest of the arrival.  At this time ATC said we were cleared the RNAV (Z) 30L.  We quickly reprogrammed FMC and briefed the new approach; everything looked good.Passing about 17;000 feet MSL; Approach transmitted what I heard to be '(call sign) are you going to make the altitudes on the approach?'  I looked down and we were on VNAV PATH; showing over 3;000 feet low.  I then looked at STAR and saw we had no restriction; being in a critical phase; I told ATC to give us a vector if we needed it which he did.My FO believes that he was asking us if we could get down for the altitude of the new approach.  As we looked at the LEGS page; we discovered that the 'clean up' of the LEGS page never occurred; and in fact it showed us going to KLIDE then back out to GILRO then back to KLIDE.  When he did clean it up; and closed discrepancies; it showed about 3;000 feet high.  While we may have salvaged it; it would have been a handful and taking the vector was a better course of action.  Uneventful approach and landing afterwards.We thoroughly debriefed the event and determined the error.  Selecting GILRO as a transition should never had been done and once it was noting the discrepancy on the LEGS page; and informing me and cleaning it up at the moment should have occurred.  ATC asked us to fill out an ASAP as this has apparently happened before and wanted the Company to note it.
A B737 Captain is queried by ATC about not descending quickly enough to make the instrument approach into SJC and a vector is accepted. The SILCN1 STAR had been connected to the ILS 30L approach at KLIDE without removing the GILRO fix producing extra mileage and a late descent.