Shift Schedules
As mentioned earlier, the TCM has programming that allows it to select a variety of shift schedules. Shift schedule selection is dependent on the following:
- Shift lever position
- Throttle position
- Engine load
- Fluid temperature
- Software level
As driving conditions change, the TCM appropriately adjusts the shift schedule. Refer to the following table to determine the appropriate operation expected, depending on driving conditions. Refer to 42RLE Shift Schedule .
42RLE Shift Schedule
| Schedule | Condition | Expected Operation |
|---|---|---|
| Extreme Cold | Oil temperature at start-up below -27° C (-16° F) | Park, Reverse, Neutral and 2nd gear only (prevents shifting which may fail a clutch with frequent shifts) |
| Cold | Oil temperature at start-up above -25° C (-12° F) and below 2° C (36° F) | - Delayed 2-3 upshift (approximately 22-31 mph) |
| - Delayed 3-4 upshift (45-53 mph) | ||
| - Early 4-3 coastdown shift (approximately 30 mph) | ||
| - Early 3-2 coastdown shift (approximately 17 mph) | ||
| - High speed 4-2, 3-2, 2-1 kickdown shifts are prevented | ||
| - No EMCC | ||
| Warm | Oil temperature at start-up above 2° C (36° F) and below 27° C (80° F) | - Normal operation (upshift, kickdowns, and coastdowns) |
| - No EMCC | ||
| Hot | Oil temperature at start-up above 27° C (80° F) | - Normal operation (upshift, kickdowns, and coastdowns) |
| - Full EMCC, no PEMCC except to engage FEMCC (except at closed throttle at speeds above 70-83 mph) | ||
| Overheat | Oil temperature above 115° C (240° F) or engine coolant temperature above 118° C (244° F) | - Delayed 2-3 upshift (25-32 mph) |
| - Delayed 3-4 upshift (41-48 mph) | ||
| - 3rd gear FEMCC from 30-48 mph | ||
| - 3rd gear PEMCC from 27-31 mph | ||
| Super Overheat | Oil temperature above 127° C (260° F) | - All "Overheat" shift schedule features apply |
| - 2nd gear PEMCC above 22 mph | ||
| - Above 22 mph the torque converter will not unlock unless the throttle is closed or if a wide open throttle 2nd PEMCC to 1 kickdown is made |