Sable Check Engine Light

engines
lights
transmissions

#1

I have a 99 Sable SW, 3L engine. The check engine light comes on sporadically…more often during highway driving. The Ford dealer diagnosed it as code P1744 (hard code), that the torque converter is sticking and that the transmission needs to be removed and overhauled. He said would last a few months tops. That was almost a year ago and I’ve continued to drive it. The car always runs fine with no apparent transmission problems. The only possible symptom is poorer gas mileage than I envisioned. It has 82,000 miles on it. I took it to a transmission guy who tested it and said everything was A-OK, though the check engine light was off by the time I got it to him. Others have told me it could be the TCC lock-up solenoid or the Vehicle Speed Sensor.



Anyone have a similar experience and/or thoughts and suggestions? I don’t want to spring for something unneeded, yet I also don’t want to ruin the transmission and get stuck somewhere on a trip.



Any feedback would be appreciated. Thanks.


#2

I am not all that clear on what the dealer meant by ‘torque converter sticking’. Usually TCs slip, shudder, fail to lockup, or fail to unlock. If it is slipping or failing to lock up, that could explain your poor gas mileage. Usually a slipping TC clutch will send trash to the transmission cooler eventually plugging it up and causing the tranny to overheat. A pan removal will usually find the debris in the bottom of the pan. If the problem is failure to lockup or unlock, the problem is usually a lockup solenoid problem; its associated valving problem; or wiring problem from the PCU to the transmission. It is unlikely to be the Vehicle Speed Sensor as that is needed by the PCU to determine the shift points. If that signel is missing, the PCU would put the transmission into limp home mode which is 2nd or 3rd gear (not exactly sure which on Fords).

I don’t know what to suggest you do. If you need to replace the TC, you are so far along in the disassembly that you might consider an overhaul. But, 82K is pretty low mileage for a rebuild. The diagnosis from the pan debris and maybe a pressure check and stall tests might steer you closer to the decision.