DTC 45: Receiver Processing Currently In 20-Second Lock-Out: Description

At least 50 consecutive digital RF messages were received from a remote keyless entry system transmitter that is programmed to BCM, but message did not pass encryption security test. BCM will cease processing any remote keyless entry system transmitter digital RF messages (good or bad) for 20 seconds. No remote function capabilities will exist.

DTC 45 will set when remote keyless entry system transmitter has been in program or resync mode while out of range of BCM. Fault may also be present if transmitter is defective. Fault could be induced prior to BCM entering diagnostic mode.

Most likely cause is that remote keyless entry system transmitter is out of sync with BCM. To resync transmitter, press LOCK and UNLOCK buttons on transmitter simultaneously for 5 seconds.