Test Procedure
All pressure readings should be taken with the transmission fluid level full, transmission oil at the normal operating temperature, and the engine at 1500 RPM. Check the transmission for proper operation in each gear position that is in question or if a specific element is in question, check the pressure readings in at least two gear positions that employ that element. Refer to Schematics and Diagrams to determine the correct pressures for each element in a given gear position.
The 68RFE utilizes closed loop control of pump line pressure. The pressure readings may therefore vary greatly but should always follow line the desired pressure.
Some common pressures that can be measured to evaluate pump and clutch performance are the upshift/downshift pressures, garage shift pressures, and TCC pressure. The upshift/downshift pressure for all shifts are shown in the tables below. Refer to UPSHIFT PRESSURES . Refer to DOWNSHIFT PRESSURES . In-gear maximum pressure for each gear position is shown in IN-GEAR PRESSURES .
| 545RFE | ||||||||
| ENGINE | 1-2 | 2-3 | 2prime-3 | 3-4 | 2prime-4 | 2-5 | 3-5 | 4-5 |
| 5.7L | 150 | 125 | 125 | 135 | 135 | 135 | 135 | 135 |
| 68RFE | ||||||||
| ENGINE | 1-2 | 2-3 | 3-4 | 4-5 | 5-6 | 2-4 | 3-5 | 4-6 |
| 6.7L | 160 | 150 | 150 | 160 | 160 | 150 | 150 | 160 |
| 545RFE | ||||||||||
| ENGINE | 5-4 | 5-3 | 5-2 | 4-3 | 4-2prime | 3-2 | 3-2prime | 2prime-1 | 2-1 | |
| 5.7L | 135 | 135 | 135 | 135 | 135 | 135 | 135 | 135 | 135 | |
| 68RFE | ||||||||||
| ENGINE | 6-5 | 6-4 | 5-4 | 5-3 | 4-3 | 4-2 | 3-2 | 3-1 | 2-1 | - |
| 6.7L | 150 | 150 | 150 | 160 | 150 | 160 | 150 | 160 | 160 | - |
| 545RFE | ||||||||
| ENGINE | 1 | 2 | 2prime | 3 | 4 | 5 | NEUTRAL | REVERSE |
| 5.7L | 160 | 135 | 135 | 135 | 135 | 135 | 120 | 250 |
| 68RFE | ||||||||
| ENGINE | 1 | 2 | 3 | 4 | 5 | 6 | NEUTRAL | REVERSE |
| 6.7L | 160 | 150 | 150 | 160 | 160 | 160 | 125 | 250 |
Actual line-pressure while in-gear will vary based upon minimum learned line-pressure. Minimum line-pressure starts at 40 psi and learns up to the minimum pressure to hold the clutches in a applied state.