B737 first officer reported captain aborted takeoff due to master caution light illumination.

Attributes
ACN	1753340
Time
Date	202007
Local Time Of Day	0001-0600
Place
Locale Reference	ZZZ.Airport
State Reference	US
Environment
Light	Daylight
Aircraft 1
Make Model Name	B737-800
Operating Under FAR Part	Part 121
Flight Phase	Takeoff
Flight Plan	IFR
Component
Aircraft Component	Engine Indications
Person 1
Function	First Officer Pilot Not Flying
Qualification	Flight Crew Air Transport Pilot (ATP) Flight Crew Instrument Flight Crew Multiengine
Experience	Flight Crew Last 90 Days 150 Flight Crew Type 1500
Events
Anomaly	Aircraft Equipment Problem Less Severe

Narrative:

During the takeoff roll at approximately 75 knots; the master caution light illuminated. No indication was made on the annunciator panel and it was unclear what caused the master caution light to illuminate. The captain elected to abort the takeoff. After clearing the runway we saw that the number 2 engine control annunciator was illuminated. 'Overhead' was never illuminated on the annunciator panel. We taxied back to a gate; called maintenance and swapped aircraft.

Original NASA ASRS Text

Title: B737 First Officer reported Captain aborted takeoff due to Master Caution light illumination.

Narrative: During the takeoff roll at approximately 75 knots; the Master Caution light illuminated. No indication was made on the annunciator panel and it was unclear what caused the Master Caution light to illuminate. The Captain elected to abort the takeoff. After clearing the runway we saw that the number 2 Engine Control annunciator was illuminated. 'Overhead' was never illuminated on the annunciator panel. We taxied back to a gate; called maintenance and swapped aircraft.

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.