[DeltaP]

P0751 possible causes: Low trans fluid level, dirty fluid, bad 1-2 shift solenoid valve, 1-2 shift solenoid harness or connectors, 1-2 shift solenoid circuit open or shorted. A buddy told me the harness connector wiring gets brittle from age and heat and becomes problematic or intermittent. Also since the problem comes and goes you can try some Lucas transmission treatment. He's said theres been some success with that cleaning up the valve body and solenoids. HTH