Need help from someone who has gone beyond the manuals and resolved similar problems. I am hoping someone will know what signals the ECM uses to determine the P0753 fault. I cannot find a good explanation of what purpose the " Pulse Conversion Circuit" is used for.
OBD II code is P0753 indicating transaxle Solenoid #1 open or shorted.
Check Engine light on, and sometimes the OD light blinks.
Symptoms: Will not downshift to 1st gear when stopped.
Diagnostics: Resistance checks at the transmission and ECM connectors checked good (used high impedance meter to prevent blowing the NPN transistors in the ECM)
Voltage reading on Solenoid 1& 2 lines indicates transaxle (A541E) is in “Fail Safe Function”
Solenoid #1 always off and solenoid #2 always on except when low gear selected.
Transmission will shift through the gears manually.
Had both #1 and #2 solenoids replaced – no change.
Old parts checked out OK after the fact.
I will appreciate any ideas or suggestions someone may have.
Thanks - Jack