2000 Pontiac Grand Am BCM vs. Ignition

Sometimes when I start my car, the lights and gauges are nonresponsive until I put the car in gear. Other than that it runs fine. The service vehicle soon light has came on once and the security light has came out about three times. I took it in to the dealer, thinking the passlock was bad again, and they told me that the BCM is why the security light was coming and that the ignition was bad, causing the gauges and lights to activate right away. Can it really be both? And can the computer sometimes be wrong with its codes? I know one time I was told that I had a bad wheel hub sensor and it was actually the wire harness.