Line Pressure Check

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:

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:
1. Install a scan tools.

CAUTION: Keep the brakes applied at all times in order to prevent unexpected vehicle motion.

NOTICE: The transmission may experience harsh, soft or mushy shifts for up to two days later.

2. Start the engine and set the parking brake.
3. Check for diagnostic trouble codes, including the diagnostic code for a stored pressure control solenoid (PCS).
4. Repair the vehicle if necessary. Include the following areas:
- Inspect the fluid level
- Inspect the manual linkage at the transmission
- Install or connect the scan tools.
- Install or connect the oil pressure gage at the line pressure tap.
5. Put the gear selector in Park and set the parking brake.
6. Start the engine and allow the engine to warm up at idle.
7. Access the PCS Control test on the scan tools.
8. Increase DESIRED PCS in 0.1 amp increments. Read the corresponding line pressure on the pressure gage. Allow the pressure to stabilize for five seconds after each current charge.
9. Compare your data to the Drive-Park-Neutral line pressure table below.

If your pressure readings differ greatly from the line pressure table, refer to the Diagnosis Tables.

The scan tools 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.

0.02 Amp 170-190 PSI
0.10 Amp 160-185 PSI
0.20 Amp 160-180 PSI
0.30 Amp 155-175 PSI
0.40 Amp 140-168 PSI
0.50 Amp 140-160 PSI
0.60 Amp 130-145 PSI
0.70 Amp 110-130 PSI
0.80 Amp 90-115 PSI
0.90 Amp 65-90 PSI
0.98 Amp 55-65 PSI

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.