Narrative:

Cruising level at 4000 feet; in and out of the tops of cumulus clouds; red oil warning light and yellow vacuum warning lights on the annunciator panel. Heard the electric vacuum backup pump come on. Oil temperature and pressure gauges were normal but I elected to declare an emergency and requested immediate routing to nearest suitable airport at 060/10 nm. I was concerned that oil warning (temperature or pressure) and vacuum failure had any association with each other. Pulled the vacuum circuit breaker and confirmed suction went to zero. Reset circuit breaker to maintain backup suction. Turned direct to ZZZ while confirming status with approach - souls on board; fuel. Elected to remain at 4;000 ft until approximately 5 nm out in case of engine failure in order to deploy cirrus parachute if necessary. Set up navigation for ILS approach. ATC directed decent to 2000 ft and advised minimum maneuvering 1;600ft. Broken cloud bases at approximately 1;500 ft allowed me to descend to VFR conditions. At approximately 3 nm from runway; I elected to cancel IFR and continue VFR in case of continued gyro or vacuum system failure. Landed without incident. Maintenance confirmed engine driven vacuum pump shaft sheared and wiring error between oil warning and vacuum failure red lights. When engine driven pump failed; red vacuum warning light should have been lite; not the oil warning. Note that pre-start annunciator checks show both oil and vacuum lights lite; after start; both lights are out. There is no way to determine wiring error until one has a vacuum failure or an oil warning due to temperature or pressure problems. Maintenance and cirrus techs are researching problem to determine whether problem is in factory wiring; annunciator lens; or connector problem.

Related reports:

Google
 

Original NASA ASRS Text

Title: SR20 pilot experiences a Red Oil Warning Light and a Yellow Vacuum Warning Light on the Annunciator Panel at 4000 feet. The oil temperature and pressure but the reporter elects to declare an emergency and divert to a suitable airport. Maintenance discovers the vacuum pump shaft sheared and the warning light system improperly wired.

Narrative: Cruising level at 4000 feet; in and out of the tops of cumulus clouds; Red Oil Warning Light and Yellow Vacuum Warning Lights on the Annunciator Panel. Heard the Electric Vacuum backup pump come on. Oil Temperature and Pressure gauges were normal but I elected to declare an emergency and requested immediate routing to nearest suitable airport at 060/10 nm. I was concerned that Oil Warning (Temperature or Pressure) and Vacuum Failure had any association with each other. Pulled the Vacuum circuit breaker and confirmed suction went to zero. Reset circuit breaker to maintain backup suction. Turned direct to ZZZ while confirming status with Approach - Souls on Board; fuel. Elected to remain at 4;000 ft until approximately 5 nm out in case of engine failure in order to deploy Cirrus Parachute if necessary. Set up Navigation for ILS approach. ATC directed decent to 2000 ft and advised minimum maneuvering 1;600ft. Broken cloud bases at approximately 1;500 ft allowed me to descend to VFR conditions. At approximately 3 nm from runway; I elected to cancel IFR and continue VFR in case of continued gyro or vacuum system failure. Landed without incident. Maintenance confirmed engine driven vacuum pump shaft sheared and wiring error between Oil Warning and Vacuum Failure red lights. When Engine driven pump failed; Red Vacuum warning light should have been lite; not the Oil Warning. Note that pre-start annunciator checks show both Oil and Vacuum lights lite; after start; both lights are out. There is no way to determine wiring error until one has a Vacuum failure or an Oil Warning due to temperature or pressure problems. Maintenance and Cirrus techs are researching problem to determine whether problem is in factory wiring; Annunciator lens; or connector problem.

Data retrieved from NASA's ASRS site as of April 2012 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.