Line pressures are calibrated for two sets of gear ranges - Drive-Park-Neutral, and Reverse. This allows the transmission line pressure to be appropriate for different pressure needs in different gear ranges:
Gear Range | Line Pressure Range |
---|---|
Drive, Park or Neutral | 55-189 psi |
Reverse | 64-324 psi |
Before performing a line pressure check, verify that the pressure control solenoid for the transmission is receiving the correct electrical signal from the PCM:
Caution: Keep the brakes applied at all times in order to prevent unexpected vehicle motion. Personal injury may result if the vehicle moves unexpectedly.
Notice: The transmission may experience harsh, soft or mushy shifts for up to two days later.
• | Inspect the fluid level |
• | Inspect the manual linkage at the transmission |
• | Install or connect the tech 1® scan tool. |
• | Install or connect the oil pressure gage at the line pressure tap. |
If your pressure readings differ greatly from the line pressure chart, refer to the Diagnosis Charts.
The tech 1® scan tool is only able to control the pressure control solenoid in Park and Neutral with the vehicle stopped. This protects the clutches from extremely high or low pressures in Drive or Reverse ranges.
Pressure Control Solenoid Current (Amp) | Approximate Line Pressure (PSI) |
---|---|
0.02 | 170-190 |
0.10 | 165-185 |
0.20 | 160-180 |
0.30 | 155-175 |
0.40 | 148-168 |
0.50 | 140-160 |
0.60 | 130-145 |
0.70 | 110-130 |
0.80 | 90-115 |
0.90 | 65-90 |
0.98 | 55-65 |
The pressures in the table assume an engine speed of 1500 RPM and a temperature of 66°C (150°F). The pressure will vary with a change in temperature.