2002 Saturn L300 codes P1811 & P0742

The P0811 indicated there is excessive clutch slippage. The PCM (Power Control Module) controls transmission shifts. The PCM also times how long each shift takes. If the PCM notes that the shift times are too long, the code p1811 will be set. A faulty transmission fluid pressure control solenoid can cause this problem. The solenoid needs tested as per GM procedures. If it fails, then it should be replaced. Chances are this is what is causing your problems.

The P0741 indicates a torque converter clutch circuit stuck on. This code can be caused by low fluid, very dirty fluid, the clutch solenoid valve, wiring, or there could be an internal issue. What I have found over the years is that most times, the problem isn't related to the electrical components but rather dirt which restricts flow of fluid to the solenoid. It wouldn't hurt to flush the transmission. Also, it would be a good idea to remove the pan to check for excessive clutch or foreign material materials which could indicate worn clutches or hard part damage. If that is found, then the transmission will either need rebuilt or replaced.

Does the transmission need replaced? Chances are NO. However, you should have a shop inspect it that you trust and will do the proper tests to determine where the problem is coming from. Also, 80K miles shouldn't have worn the transmission out unless it was abused.

I'm sorry, but I am in Pittsburgh and know no one in that area. Ask around so you find someone that knows what he / she is doing and doesn't just jump to conclusions. Also, you may want to try having the transmission serviced. Often times dirt will cause similar issues to which you are having. If you have the system power flushed (which should remove all fluid), you should still have the transmission pan removed and inspected. At that time, have them replace the filter too. Most shops will power flush a transmission and not replace the filter because the process doesn't require pan removal. The fluid is actually removed and replaced via the cooling lines.

Let me know if you have other questions or need help with something.

Regina:

I hope I was helpful. Take care,

Joe

Just to add to this one the number one cause for the p1811 is a bad line pressure actuator I have replaced tons of them for that code. Also I really dont recommend power flushing the transmission with a flush machine just a drain the fluid replace the filter clean the pan out etc.I would also check the pan for excessive debris. Those transmissions really need the fluid every 50K they have fiberous clutches as they wear they leave the clutch material suspended in the fluid and if the fluid is changed when its supposed to or not the materials get into the solenoids and cause issues.