DTC 42, Last Transmitter Message Received Had Invalid Id
The digital RF message received was from a remote keyless entry system transmitter not programmed to BCM. Remote function capabilities will not exist.
A remote keyless entry system transmitter was used without programming it to BCM. If transmitter was already programmed, transmitter may be defective.
BCM should be placed in remote keyless entry system programming mode. Both transmitter must be programmed to BCM simultaneously. See ANTI-THEFT SYSTEM article.