In a nutshell. 1998 Saturn SL2 Auto Tranny does not shift into overdrive (last gear). No other problems with tranny at all. Shifts perfect except for when its time to shift into the last gear going about 40-50 mph. It tries to go into OD once and the RPM's rev then it goes back into fourth and stays. TROUBLE CODE IS P0734 - Incorrect 4th Gear Ratio (this is the only code that it ever gave for me and the previous owner - no other issues with tranny). I checked all electrical connections, cleaned with electric cleaner spray, put ohm meter to wire harness on valve body and solenoids checked OK at right resistance. Board that snaps over the solenoids in valve body looks in good shape too. Fluid and filter are new and at proper level. I bought a new shift solenoid but have not put it in yet because they all read proper resistance and I am unsure if this is the cause. MY QUESTION IS. Can a solenoid still be bad or partially failed even though it shows proper resistance? Can the A/T fluid temperature sensor cause the overdrive to slip and not engage? What other parts can cause this? (Clutch pack for that gear? Transaxle range switch out of adjustment?) I want to get some advice from professionals before I take the valve body apart again. Thanks in advance and any help would be greatly appreciated!
Thursday, January 12th, 2012 AT 4:13 PM