IndyCar has rescinded the $20,000 fine levied against Chevrolet last month for breaches of rules regarding traction control and launch control, although the deduction of 10 manufacturer points still stands.
The manufacturer was issued the fine and points deduction when the breaches were detected after the inaugural race on the Indianapolis road course.
Chevrolet immediately declared its intention to appeal, and a statement issued by IndyCar on Tuesday confirmed that the manufacturer's protest had largely been successful.
"IndyCar announced today that it has rescinded penalties issued against Chevrolet for violation of IndyCar Series engine regulations 11.2 (Torque Control) and 12.1 (Traction Control)," said the statement.
"The engine manufacturer will be assessed a deduction of 10 manufacturer points for an unintentional technical violation."
Chevrolet was also docked 10 manufacturer points for an unrelated breach of the rule dictating the minimum engine mileage threshold for an unapproved change of engine in Juan Pablo Montoya's car at Detroit last weekend.