The accident happened on the northbound carriageway of the toll road between junctions three and four on Wednesday morning.
Emergency services were also at the scene, but it is not yet known if anyone has been injured.
A post from the M6 Toll on Twitter said: "A road traffic accident is currently affecting traffic northbound between junction T3 and T4.
Lane 3 is affected with all traffic passing in lanes 1 and 2.
Our team is at the scene assisting with the emergency services. We apologise if this may affect your journey."
West Midlands Police said members of the public had also reported that a car had broken down in the fast lane of the M6 Toll on Wednesday morning.