Cheshire coroner Nicholas Rheinberg gave the cause of death as hanging but said "the evidence does not sufficiently determine whether this was intentional or accidental".
The inquest at Warrington Coroner's Court heard that Speed texted his wife days before his death and "talked in terms of taking his life".
The couple also "had words" on the night before he was found dead after they had been to a dinner party at a friend's house.
Speed was found hanged at his Cheshire home on November 27 last year by his wife Louise.
But Mr Rheinberg said, in a narrative verdict, that the football manager may have "nodded off" while sitting with cable around his neck on the stairs in his garage!
Mrs Speed: "We walked in the house and we had an exchange of words about something and nothing.
"I went upstairs and lay on the bed for probably about five or 10 minutes.
"Then I decided to go for a drive, to clear my mind (and for) space to think."
Questioned further by Mr Rheinberg, she said she only drove to the "top of the road" before she stopped to ring her husband's mobile phone.
After getting no reply, she returned to the house and tried, unsuccessfully, to ring him again.
"I decided to keep the car running and stay there until I could get into the house," she explained.
After getting some sleep in the vehicle she told the hearing she woke up at about 6am and went to the outside bathroom.
She said she noticed some shed keys missing which were usually stored there and went to the shed to see if Gary was there, before moving to the garage.
Blinking away tears she said: "I went to the window and there I saw him."
She nodded as Mr Rheinberg asked: "Could you see Gary on the stairs?"
He continued: "Was it apparent that Gary was hanging?"
"Yes," Mrs Speed told him.
She said she then woke the children to open up the house and called the emergency services.
On their advice, she cut her husband to the ground as paramedics were sent to the scene.
The sportsman was hanging from a bannister with a piece of television aerial, the court has heard.
Mrs Speed confirmed there was no note or message left by her husband before his death.