Need info on computer trouble codes: “PO 742 Torque Converter Clutch Stuck On” and “P1811 Maximum Shift Adaptive”. Car almost stalled, Svc Eng Soon lght came on. Next day had corrected itself. Mechanic says $2,500 to rebuild trans. Also says to drive until it happens again and then bring it in. Afraid of long trips. Opinions will be appreciated and also info on the two troble codes.
The P0742 code is probably a sticking torque converter lockup solenoid or the spool valve is sticking. This usually can be serviced without removing or overhauling the transmission.
The P1811 code is of concern. Did the CEL go out when the problem corrected itself. A capable scanner can pull the adaptive shift information to find out which shift is causing problems for the PCM i.e. transmission computer. If the PCM is not able to adapt the line pressure to get a satisfactory shift it is at ‘maximum shift adaptive’. That might be indicative of a failing clutch pack or leaky internal seals. The transmission technician should be able to pull this information and with a line pressure check determine whether it was caused by the locked TC or if it can be only solved with a transmission rebuild.
Hope this helps. Let us know what happens in the future. Hopefully, transman618 will chime in.
Researcher, thanks for the info. The CEL DID go out when the problem corrected itself and has not come on again. Any ideas about the safety factor if I continue to drive the car? Also, is it likely to fail completely on a long highway trip? Would not like to be stranded 500 milels from home.
I’m more concerned about the P-0742. The P-1811 sets when the maximum allowable shift time has exceeded. This code did not turn the check engine light on, it was the P-0742 which did. The reason this code sets could either be a pressure regulator problem. The pressure regulator issue causes the line pressure to rapidly fluctuate which will set this code and possibly cause the engine to stall. Also, with this code we have been finding broken sealing rings on the turbine shaft which has been damaging the shaft and the channel plate. I would pull the pan next and see if there is any brass in there.
transman