J 21867 Pressure Gauge
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 | 35-171 psi |
Reverse | 67-324 psi |
Before performing a line pressure check, verify that the pressure control solenoid for the transmission is receiving the correct electrical signal from the vehicle computer:
Caution: Keep the brakes applied at all times in order to prevent unexpected vehicle motion. Personal injury may result if the vehicle moves unexpectedly.
Important: 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 scan tool |
• | Install or connect the J 21867 at the line pressure tap |
Important: Be sure to apply pipe thread sealant with Teflon, GM P/N 2346004, to the line pressure plug.
If your pressure readings differ greatly from the line pressure table, refer to the Diagnosis Tables.
The scan tool is only able to control the pressure control solenoid in Park and Neutral with the vehicle stopped at idle. This protects the clutches from extremely high or low pressures in Drive or Reverse ranges.