AUTOMATIC TRANSAXLE SYSTEM, Diagnostic DTC:P2808

DTC Code DTC Name
P2808 Pressure Control Solenoid "G" Performance (Shift Solenoid Valve SL4)

DESCRIPTION

The ECM uses the vehicle speed signal and signals from the transmission speed sensors (NC, NT) to detect the actual gear (1st, 2nd, 3rd, 4th, 5th or 6th gear).

Then the ECM compares the actual gear with the shift schedule in the ECM memory to detect mechanical problems of the shift solenoid valves and valve body.

DTC No. DTC Detection Condition Trouble Area
P2808

The engine revs freely when 3rd or 5th gear is commanded. (2-trip detection logic)

When any of the following is detected. In addition, the condition that 4th gear is engaged when 4th gear is commanded occurs twice. (2-trip detection logic)


  • When 1st gear is commanded, 3rd gear is engaged.

  • When 2nd gear is commanded, 3rd gear is engaged.

  • When 6th gear is commanded, 5th gear is engaged.


  • Shift solenoid valve SL4 remains open or closed

  • Valve body is blocked

  • Automatic transaxle (clutch, brake or gear etc.)

MONITOR DESCRIPTION

The ECM commands gear shifts by turning the shift solenoid valves on and off. According to the input shaft revolution (speed), intermediate (counter) shaft revolution (speed) and output shaft revolution (speed), the ECM detects the actual gear (1st, 2nd, 3rd, 4th, 5th or 6th gear). When the gear commanded by the ECM and the actual gear are not the same, the ECM illuminates the MIL and stores the DTC.

INSPECTION PROCEDURE

PROCEDURE


  1. CHECK OTHER DTCS OUTPUT (IN ADDITION TO DTC P2808)


    1. Connect the intelligent tester to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the intelligent tester on.

    4. Enter the following menus: Powertrain / Engine and ECT / DTC.

    5. Read the DTCs using the intelligent tester.

      Result
      Display (DTC output) Proceed to
      Only "P2808" is output A
      "P2808" and other DTCs are output B

      Tech Tips

      If a solenoid is stuck OFF, DTCs for several solenoids including the malfunctioning solenoid will be detected.


    A
    B
  2. PERFORM ACTIVE TEST USING INTELLIGENT TESTER

    Note

    This test should always be performed with at least 2 people.


    1. Warm up the engine.

    2. Turn the ignition switch off.

    3. Connect the intelligent tester to the DLC3.

    4. Turn the ignition switch to ON.

    5. Turn the intelligent tester on.

    6. Enter the following menus: Powertrain / Engine and ECT / Active Test.

    7. According to the display on the intelligent tester, perform the Active Test.

      Tech Tips

      Comparing the gear commanded by the Active Test with the actual gear enables confirmation of the problem Click here.

      Tester Display Test Details Control Range Diagnostic Note
      Control the Shift Position Operates the shift solenoid valves to allow gears to selected manually.
      • Press "→" button: Upshift occurs

      • Press "←" button: Downshift occurs

      Can be used to check the operation of the shift solenoid valves.

      Upshifts and downshifts should be performed consecutively. A 10-second interval is required between gear changes.

      Do not downshift at high speeds.

      Doing so will damage the automatic transaxle.

      [Vehicle Condition]

      50 km/h (31 mph) or less

      Note


      • This test can be conducted when the vehicle is stopped.

      • When shifting gears using the Active Test function, do not operate the accelerator pedal for 2 seconds before and after shifting gears.

      Tech Tips

      The gear commanded by the ECM is shown in the Data List / Shift Status display on the intelligent tester.

    8. Check the vehicle speed and the gear when the engine speed is 1000 rpm.

      Tech Tips

      Because the torque converter has not engaged, it may be difficult to obtain the speeds specified in 4th, 5th, and 6th gear, however a difference of speed should still be evident following each gear change.

      Standard
      1st 2nd 3rd 4th 5th 6th
      8 to 12 km/h (5 to 7.5 mph) 15 to 19 km/h (9.3 to 11.8 mph) 21 to 25 km/h (13.0 to 15.5 mph) 31 to 35 km/h (19.3 to 21.7 mph) 44 to 48 km/h (27.3 to 29.8 mph) 52 to 56 km/h (32.3 to 34.8 mph)
    9. Compare the ECM commanded gear and the actual gear.

      Result
      Actuator Gear during Malfunction ECM Commanded Gear Proceed to
      1st 2nd 3rd 4th 5th 6th
      Shift solenoid SL1 Stuck ON 1st 2nd 3rd 4th 4th 4th A
      Stuck OFF N*1 N*1 N*1 N*1 5th 6th
      Shift solenoid SL2 Stuck ON 4th 4th 4th 4th 5th 6th B
      Stuck OFF 1st 2nd 3rd 1st N*1 N*1
      Shift solenoid SL3 Stuck ON 2nd 2nd 3rd 4th 5th 6th C
      Stuck OFF 1st 1st 3rd 4th 5th N*1
      Shift solenoid SL4 Stuck ON*3 3rd 3rd 3rd 4th 5th 5th D
      Stuck OFF 1st 2nd 1st 4th N*1 6th
      Shift solenoid SLT Stuck ON N*2 N*2 N*2 N*2 N*2 N*2 E
      Stuck OFF*3 1st 2nd 3rd 4th 5th 6th

      Tech Tips


      • *1: Neutral

      • *2: If shift solenoid SLT is stuck on, the line pressure will be low. Therefore, the amount of torque that can be transmitted by each gear is lower than the normal limit. When the engine power exceeds this lowered limit, the engine speed will increase freely.

      • *3: When shift solenoid SLT is stuck off, gear shifting is normal.


    A
    B
    C
    E
    D
  3. INSPECT SHIFT SOLENOID VALVE SL4


    1. B000HN3E01
      Text in Illustration
      *1 Shift Solenoid Valve SL4

      Remove shift solenoid valve SL4.

    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Condition Specified Condition
      1 - 2 20°C (68°F) 5.0 to 5.6 Ω
    3. Connect a battery positive (+) lead with a 21 W bulb to terminal 2 and a negative (-) lead to terminal 1 of the solenoid valve connector. Then check that the valve moves and makes an operating sound.

      OK
      Valve moves and makes an operating sound.

    NG
    OK
  4. INSPECT TRANSMISSION VALVE BODY ASSEMBLY


    1. Check the transmission valve body assembly Click here.

      OK
      There are no foreign objects on each valve and they operate smoothly.

    NG
    OK