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Home >> Mazda >> 2021 >> CX-9 Signature >> Repair and Diagnosis >> Transmission >> Automatic Trans >> Automatic Transaxle (Service Information) >> Mechanical System Test >> Line Pressure Test

Line Pressure Test

  1. Perform the mechanical system test preparation. (See Mechanical System Test Preparation .)
  2. Remove the following parts as a single unit. (See INTAKE-AIR SYSTEM REMOVAL/INSTALLATION [SKYACTIV-G 2.5T] .)
    • Air cleaner cover
    • Air cleaner element
    • Fresh-air duct
    • Air cleaner case
    • Air hose
  3. Disconnect the wiring harness clip from the harness bracket.
    G11441150Courtesy of MAZDA MOTORS CORP.
  4. Disconnect the oil pipe No. 1 from the harness bracket with the oil hose connected. (With oil cooler No. 2)
    G11440986Courtesy of MAZDA MOTORS CORP.
  5. Remove the harness bracket.
    Fig 1: Square Head Bolt With Torque Specification
    G11441152Courtesy of MAZDA MOTORS CORP.
  6. Remove the pressure detection square head plug.
    WARNING:
    • Do not remove the square head plug when the ATF temperature is high. Otherwise, ATF could overflow and cause severe burns or serious injury. Remove the square head plug when the transaxle and ATF temperatures are low.
    NOTE:
    • Use a suitable oil pressure gauge that corresponds to the line pressure because the maximum scale value differs depending on the oil pressure gauge.
    G12244766Courtesy of MAZDA MOTORS CORP.
  7. Install SSTs (49 D019 908, 49 D019 909, 49 D019 910, 49 D019 911, 49 D019 913) to the line pressure detection port as shown in the figure.
    G11429162Courtesy of MAZDA MOTORS CORP.
  8. Install the following parts as a single unit. (See INTAKE-AIR SYSTEM REMOVAL/INSTALLATION [SKYACTIV-G 2.5T] .)
    • Air cleaner cover
    • Air cleaner element
    • Fresh-air duct
    • Air cleaner case
    • Air hose
  9. Start the engine.
  10. Warm up the engine until the ATF temperature is 60-70°C {140-158°F}.
  11. Shift the selector lever to the D position.
  12. Measure the line pressure while idling in D position.
  13. Measure the line pressures while idling in the M (1st gear) and R positions using the same procedure.
  14. Stop the engine.
  15. Change the low-pressure gauge (49 D019 908) to the high-pressure gauge (49 D019 907).
    G11429163Courtesy of MAZDA MOTORS CORP.
  16. Start the engine.
  17. Measure the line pressure while stalling in D position.
    1. Strongly depress the brake pedal with the left foot.
    2. Shift the selector lever to the D position.
      CAUTION:
      • To prevent damage to the transaxle, measure the line pressure while stalling (Step (3)-(4)) within 5 s.
    3. Slowly depress the accelerator pedal fully with the right foot all the way down.
    4. Read the line pressure quickly while stalling, and remove the right foot from the accelerator pedal.
    5. Shift the selector lever to the N position and idle for 1 min or more.
  18. Measure the line pressure while stalling for positions other than D in the same procedure.
    • If there is any malfunction, one of the following causes may have occurred.
    Condition POSSIBLE CAUSE
    Lower than specification Lower in R, D, and M (1GR) position  
    • Oil pump wear
    • ATF leakage from oil pump, control valve body, and transaxle case
    • Pressure regulator valve sticking
    • Pressure control solenoid malfunction
    • Solenoid reducing valve sticking
    Lower in D and M (1GR) position  
    • ATF leakage from low clutch hydraulic circuit
    Lower in R and M (1GR) position  
    • ATF leakage from low and reverse brake hydraulic circuit
    Lower in R position  
    • ATF leakage from R-3-5 brake hydraulic circuit
    Higher than specification Higher in R, D, and M (1GR) position  
    • Pressure regulator valve sticking
    • Pressure control solenoid malfunction

    Line pressure 

    LINE PRESSURE SPECIFICATION

    Measurement conditions Specification (kPa {kgf/cm2 , psi})
    Idling R position 500-700 {5.10-7.13, 72.6-101.0}
    D and M (1GR) position 330-470 {3.37-4.79, 47.9-68.1}
    Stalling R position 1, 790-2, 100 {18.26-21.41, 259.7-304.5}
    D and M (1GR) position 970-1, 170 {9.90-11.93, 141.0-169.6}
  19. Stop the engine.
  20. Remove the following parts as a single unit. (See INTAKE-AIR SYSTEM REMOVAL/INSTALLATION [SKYACTIV-G 2.5T] .)
    • Air cleaner cover
    • Air cleaner element
    • Fresh-air duct
    • Air cleaner case
    • Air hose
  21. Remove the SSTs.
    WARNING:
    • If the SST is removed when the ATF temperature is high, ATF could overflow and cause severe burns or serious injury. Remove the SST when the transaxle and ATF temperatures are low.
  22. Install a new square head plug.
    NOTE:
    • Do not reuse the square head plug because a sealant coating has been applied.

    Tightening torque 

    7.2-9.8 N.m {74-99 kgf.cm, 64-86 in.lbf}

  23. Install the harness bracket.
    G11441152Courtesy of MAZDA MOTORS CORP.

    Tightening torque 

    8-10 N.m {82-101 kgf.cm, 71-88 in.lbf}

  24. Install the oil pipe No. 1 to the harness bracket. (With oil cooler No. 2)
    Fig 2: Oil Pipe No. 1 Harness Bracket Bolt With Torque Specification (With Oil Cooler No. 2)
    G11441157Courtesy of MAZDA MOTORS CORP.
  25. Connect the wiring harness clip to the harness bracket.
    G11441150Courtesy of MAZDA MOTORS CORP.
  26. Install the following parts as a single unit. (See INTAKE-AIR SYSTEM REMOVAL/INSTALLATION [SKYACTIV-G 2.5T] .)
    • Air cleaner cover
    • Air cleaner element
    • Fresh-air duct
    • Air cleaner case
    • Air hose
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