Pierre Gasly is left facing a possible grid penalty this weekend following the fire which prematurely ended his FP2 session.
"We know the initial incident was caused by an electrical blackout on the car," said Honda of the fire which resulted in one of the two red flag periods that compromised running in the afternoon. "We are now carrying out out a full physical check on the PU itself."
The Monza winner is already on his third ICE, MGU-H, MGU-K and turbo, therefore another of any of these components would result in an immediate penalty.
The fire brought the Frenchman's afternoon to an immediate end, meaning that he has yet to do any running on anything other than the prototype tyres and the hards.
"Literally, 5 seconds before I stopped I just lost everything," he said. "The steering, the electricity in the car.
"We're still investigating what happened," he continued. "Obviously there was a lot of fire at the back of the car and things burning, so we need to analyse and know what happened.
"For sure it's not ideal," he admitted, "especially because we could not run the option tyre, we had only the base this morning.
"On a new track like this it's never great. But that's what we got, unfortunately. We'll try to get as much data as we can on Dany's side.
"Pace-wise it looked pretty decent all day long, but I'm still not feeling super comfortable with the car, so I think we can improve it for tomorrow. It will be important, FP3, because we need to recover these laps."
Check out our Saturday gallery from Portimao, here.