Dyson was joint second after 36 holes of the BMW Masters in October when he was disqualified for signing for an incorrect score in the second round.
The 35-year-old failed to add a two-shot penalty to his card after an incident on the eighth hole at Lake Malaren, when he touched the line of his putt after marking his ball, using the ball to flatten a spike mark.
Having reviewed the incident after being alerted to it by television viewers, European Tour officials charged Dyson with a serious breach of the Tour's code of behaviour, a charge which was upheld when the Yorkshireman appeared before a three-person disciplinary panel at Wentworth.
The panel, chaired by Ian Mill QC and made up of European Senior Tour player Gordon Brand Jnr and League Managers' Association chief executive Richard Bevan, found that Dyson deliberately pressed down the spike mark to improve his position, despite knowing it was against the rules.
According to the panel, the "extreme seriousness" of such an offence "in the appropriate case" would warrant an immediate suspension, but Dyson's previous good conduct and the fact that it was a "momentary aberration on his part, not a premeditated act of cheating", was taken into consideration.
Dyson was therefore given the suspended ban, with any breach of the Rules of Golf in the 18-month period seeing his case referred back to the panel to determine whether the suspension should immediately become effective.
The six-time European Tour winner was also fined £30,000 and ordered to pay £7,500 towards the Tour's costs, with the money to be paid within 56 days.
Dyson, who finished joint third in the Alfred Dunhill Championship in South Africa last week, and his management company declined to make any comment on the ruling.
Dyson's only public comment on the incident came via a statement released on October 31, in which he said: "I have never deliberately broken the rules either on this occasion or in the past.
"It was only after I was shown the replay of my action after marking the ball on the eighth green during the second round that I realised what I had done and that I was in breach. I immediately accepted that I should be disqualified.
"My action was in no way a deliberate act with the intention of breaking the rules. It was simply an accidental mistake which I have no reservations in apologising for and particularly to my fellow professionals and the Tour for any inconvenience and embarrassment unintentionally caused."