please help

[93blackta]

my car is throwing a code 28 which my book says "check the transmission range control circuit". i have no idea what this is. can anyone help?

[Fastbird93]

Check my post on the speed density board. Code 28 is QDM #3, sets when the ECM detects excessive voltage for 26 seconds. A/C clutch and cooling fan relays are tied in to this, don't know why your book said anything about the tranny.