Commercial captain reported a discrepancy between charted procedural altitude constraints on the map...

Narrative:

We noted a difference in a published altitude on a missed approach when comparing the approach plate with the aircraft database. We briefed the ILS 31C approach to chicago-midway airport. The missed approach instructions on the approach plate direct a left turn toward peotone and an altitude of 2;100 (or below) until crossing igecy. The legs page of the CDU displayed the igecy altitude as '2100A.' [although] our procedures should preclude an altitude deviation should a crew fly the missed approach; I believe the possibility exists. The [commercially provided] approach plate text would lead pilots to level off at 2;100. Should a pilot become busy with missed approach tasks and check the legs page for the correct altitude setting (rather than the printed approach plate); he/she could easily set the final altitude in the [map procedure] (2;600).

Original NASA ASRS Text

Title: Commercial Captain reported a discrepancy between charted procedural altitude constraints on the MAP from the ILS Runway 31C at MDW and the constraints published in the aircraft's FMS database.

Narrative: We noted a difference in a published altitude on a missed approach when comparing the approach plate with the aircraft database. We briefed the ILS 31C approach to Chicago-Midway Airport. The missed approach instructions on the approach plate direct a left turn toward Peotone and an altitude of 2;100 (or below) until crossing IGECY. The LEGS page of the CDU displayed the IGECY altitude as '2100A.' [Although] our procedures should preclude an altitude deviation should a crew fly the missed approach; I believe the possibility exists. The [commercially provided] approach plate text would lead pilots to level off at 2;100. Should a pilot become busy with missed approach tasks and check the LEGS page for the correct altitude setting (rather than the printed approach plate); he/she could easily set the final altitude in the [MAP procedure] (2;600).

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.

Attributes
ACN	1159346
Time
Date	201403
Local Time Of Day	0601-1200
Place
Locale Reference	MDW.Airport
State Reference	IL
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 121
Flight Phase	Landing
Flight Plan	IFR
Component
Aircraft Component	Navigation Database
Person 1
Function	Captain
Qualification	Flight Crew Air Transport Pilot (ATP)
Events
Anomaly	Aircraft Equipment Problem Less Severe

Commercial captain reported a discrepancy between charted procedural altitude constraints on the map from the ILS runway 31C at mdw and the constraints published in the aircraft's FMS database.