1999 trailblazer 4wd has no 4th gear and no OD...all other shifts are normal. I can plug in my scanner and delete the code(yes just one code p0740, not the famous 5 codes) while driving and as long as I'm up to speed where the command for 4th or OD is present it will shift into 4th and then OD normally and stay in OD just fine until I come to a stop and it commands the TCC to unlock then the engine light trips, the code is thrown and I have to get back up to speed clear the code and it will work normally all over again. Even after the code is cleared and the TCC is locked up you can constant the throttle at highway speeds tap the brake and the tcc will unlock and then lock again. I can manually shift into 3rd gear and clear the code and the tcc will lockup then too..but if you slow down below the speed for tcc unlock command the code will throw. So far I have read I need to test the TPS, ECT, brake switch is there a way to test the solenoids themselves without pulling pan, could the TCC pwm solenoid cause this or would the actual engagement solenoid that's wired into the harness be more likely? I'm led to believe the solenoids are functioning properly because they engage and disengage fine it's just something isn't signaling the ECM?? I'm aware the code is for tcc solenoid circuit malfunction...any ideas? Thanks friends.
Is it not signaling 4th because the converter isn't starting to engage correctly after 35mph? Maybe I need to delete the pwm solenoid?
Is it not signaling 4th because the converter isn't starting to engage correctly after 35mph? Maybe I need to delete the pwm solenoid?
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