A coil test is simple. Simply pull a spark lug wire off, place a screwdiver in it and hold it very close to a grounded bolt leaving a small garp and crank the motor over. You should get a spark. What happens is, when the coil gets hot, it expands. If there is a crack in the housing, the spark jumps out of it against the block. If this isn't the problem, then yes, it may be the ignition control module. You can't alway trust these code reads, because they will read a lot of the same codes for different problems. That is the only bad thing about computerized motors. Everysensor must be working in order to get a proper reading.