The extra lane opens up at busy times to ease congestion between junctions eight at West Bromwich and 10a at Essington.
But from January 1 to December 31 there were 74 days where it was out of action, ranging from up to nine hours to less than a minute.
The figures released under the Freedom of Information Act show there were 141 technology faults reported, with the most being in May.
But some of these applied to the same problems but on a different stretch of the main section which carries around 160,000 drivers a day.
The extra lane system, which works with cameras and signs, was brought in between the junctions in 2011 as part of a £150 million managed motorways scheme.
The cost of repairing the problems has not been revealed by the Highways Agency who say it is part of a maintenance contract.
In response to the FOI request from the Express & Star, Christine Matthews from the strategy and policy team, said: "Where a fault was discovered on both sides of the carriageway, or extended across more than one junction, this is logged as separate incidents - when it's actually the same fault. This is because of the way our control centres record incidents.
"Total costs - including those for the repair, maintenance and traffic management associated with the affected technology equipment - cannot be provided as they are not broken down specifically to the repair or location.
"The contract with the Highways Agency's service provider is based on a lump sum payment and requires the contractor to maintain the equipment."
Work to reduce congestion as part of a £87.5m 'smart motorways' project is also being carried out between junctions 10 and 13 in Staffordshire. It includes using an extra lane and technology to vary speed limits.
There are also plans to revamp the main M6 junction 10 island at Walsall under a £60m scheme.
Lanes going over the motorway will be increased from two to four under proposals to rebuild the bridges and improve traffic flow.
The ambitious project also involves widening the M6 slip roads and improving the Wolverhampton Road and Bloxwich Lane junction.
There will also be some modification work to the Black Country Route as in a bid to improve traffic flow.
Work is anticipated to start within the 2017/18 financial year, and expected to take two years to finish, with highways bosses vowing to try and minimise disruption.