My OnStar status LED changes from GREEN (Normal) to RED (Problem). Then in a few days goes back to GREEN (Normal). Dealer check out could find no problem. OnStar test reports trouble code B2470, antenna issue. LED changed GREEN to RED again twice last week. Each time in a few days the status light goes back to GREEN (normal). Each time OnStar was contacted and ran a diagnostic they came up with the same trouble code. Heading to dealer for recheck in a few weeks. Have others seen this problem?