P2004 and P2009 came up in scanner .I replaced one solenoid that was not functioning even when circuit had 12v . Other solenoid circuit only has 9-10v (closest to firewall) solenoid tested good when I apply 12v with power supply. I erased codes and only P2009 came back up. Do both circuit's need 12v or is 9v enough for them to function?
My car has 167000 miles.
My car has an automatic transmission.
If the issue persists then it may be possible that the issue is with wiring or computer. Damaged wiring or a faulty computer may compromise power to the solenoid and affect its performance. Many automotive electronic circuits use 12 volts to operate, however that is not always the case. For specifications on what the correct voltage should be I would refer to a dealership or a service manual.