DTC P1510: Engine Control Module Back-Up Power Supply Malfunction: Condition
WARNING: This page is about a different car, the 2003 Suzuki Aerio. However, it is still accessible from the selected car via links, so may be relevant.
DTC is set when ECM detects incorrect voltage at ECM back-up power supply. Battery voltage is supplied so that DTC memory values are not lost when ignition is turned off. Possible cause is battery voltage supply circuit.