Boeing 737 flight crew reported TCAS announced a climb directive when traffic was above.

Attributes
ACN	1493292
Time
Date	201711
Local Time Of Day	0601-1200
Place
Locale Reference	EWR.Airport
State Reference	NJ
Environment
Flight Conditions	IMC
Aircraft 1
Make Model Name	B737 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	Climb
Route In Use	Vectors
Flight Plan	IFR
Component
Aircraft Component	Traffic Collision Avoidance System (TCAS)
Person 1
Function	First Officer Pilot Not Flying
Experience	Flight Crew Total 2414
Person 2
Function	Captain Pilot Flying
Qualification	Flight Crew Air Transport Pilot (ATP)
Experience	Flight Crew Type 882
Events
Anomaly	Aircraft Equipment Problem Less Severe Conflict Airborne Conflict

Narrative:

We were instructed to level off at 6000 on the vector/departure out. Traffic was called out for us (VFR) and we began [our] search; although we were in and out of layered clouds. Aircraft of interest showed on our TCAS and we monitored. TCAS notified us of potential conflict 'traffic'; then directed 'climb climb' then followed that direction with 'descend' we accomplished both instructions in accordance with flight manual direction.ATC was notified; although he did not understand why we climbed since traffic was above us. We don't know either; but we followed the clear instructions of the TCAS (first climb; then descend). We ended up acquiring the VFR civil aircraft (high-wing cessna) above and to our right; well clear. ATC was notified of us being clear of traffic and we resumed the departure.

Original NASA ASRS Text

Title: Boeing 737 flight crew reported TCAS announced a climb directive when traffic was above.

Narrative: We were instructed to level off at 6000 on the vector/departure out. Traffic was called out for us (VFR) and we began [our] search; although we were in and out of layered clouds. Aircraft of interest showed on our TCAS and we monitored. TCAS notified us of potential conflict 'Traffic'; then directed 'Climb Climb' then followed that direction with 'Descend' We accomplished both instructions In Accordance With Flight Manual direction.ATC was notified; although he did not understand why we climbed since traffic was above us. We don't know either; but we followed the clear instructions of the TCAS (first climb; then descend). We ended up acquiring the VFR civil aircraft (high-wing Cessna) above and to our right; well clear. ATC was notified of us being clear of traffic and we resumed the departure.

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.