DTC P1500: Starter Signal Circuit Malfunction: Condition
WARNING: This page is about a different car, the 2002 Suzuki XL-7. However, it is still accessible from the selected car via links, so may be relevant.
DTC P1500 is set when engine starts even though vehicle is at a stop and start signal is not being inputted, or start signal is being inputted continuously while engine is running. MIL is illuminated when ECM detects malfunction during 2 consecutive drive cycles.