DTC P1510: Engine Control Module Back-Up Power Supply Malfunction: Condition
WARNING: This page is about a different car, the 2002 Suzuki Esteem. However, it is still accessible from the selected car via links, so may be relevant.
DTC is set when Engine Control Module (ECM) detects incorrect voltage at ECM back-up power supply. Battery voltage is supplied so that diagnostic trouble code memory values are not lost when ignition is turned off. Possible cause is battery voltage supply circuit.