Harsh 3-4 Upshift Only
WARNING: This page does not describe the selected car, but rather 13 other vehicles, including the 2003 Mazda B4000, 2003 Mazda B3000, 2003 Mazda B2300, 2002 Mazda B4000, and 2002 Mazda B3000. However, it is still accessible from the selected car via links, so may be relevant.
Check the following: low line pressure, valve body (TCC solenoid, 3-4 shift valve, converter clutch control valve, forward modulator valve/EPC boost valve, pressure boost valve/main regulator valve, or thermostat by-pass valve/cooler limit valve stuck or damaged), incorrectly tightened valve body bolts (cross-leaks), center support assembly, direct-reverse clutch assembly damaged, intermediate band or servo damaged or out of adjustment, or TCC assembly (internal failure).