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.

Detection Item

DTC Detection Condition

Trouble Area

MIL

Memory

P2808

Pressure Control Solenoid "G" Performance (Shift Solenoid Valve SL4)

Either condition is met (2-trip detection logic):

  • The engine revs freely when a shift to 3rd or 5th gear is commanded.

  • The condition that 4th gear is engaged when a shift to 4th gear is commanded occurs twice, and one of the following conditions is met:

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

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

    • When a shift to 6th gear is commanded, 5th gear is engaged.

  • Shift solenoid valve SL4 remains open or closed

  • Transmission valve body assembly is blocked

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

Comes on

DTC stored

MONITOR DESCRIPTION

The ECM commands gear shifts by turning the shift solenoid valves on and off. According to the input shaft speed, intermediate (counter) shaft speed and output shaft 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.

CAUTION / NOTICE / HINT

Note:

Perform registration and/or initialization when parts related to the automatic transaxle are replaced.

Click here

PROCEDURE

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

    1. Connect the GTS to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the GTS on.

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

      Powertrain > Engine and ECT > Trouble Codes

    5. Read the DTCs using the GTS.

      Result

      Result

      Proceed to

      Only P2808 is output

      A

      P2808 and other DTCs are output

      B
      Tip:

      If shift solenoid valve SL4 is stuck off, DTCs for several shift solenoid valves including the malfunctioning shift solenoid valve will be stored.

    A

    INSPECT SHIFT SOLENOID VALVE SL4Click here

    B

  2. PERFORM ACTIVE TEST USING GTS (DRIVING TEST)

    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 GTS to the DLC3.

    4. Turn the ignition switch to ON.

    5. Turn the GTS on.

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

    7. According to the display on the GTS, perform the Active Test.

      Tip:

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

        Click here

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

      Powertrain > Engine and ECT > Active Test

      Tester Display

      Measurement Item

      Control Range

      Diagnostic Note

      Control the Shift Position

      Operate the shift solenoid valves and set each shift position

      • Press "→" button: Shift up

      • Press "←" button: Shift down

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

      A 10-second interval is required between gear changes.

      Do not down-shift at high speeds. Doing so will damage the automatic transaxle.

      [Vehicle Condition]

      50 km/h (30 mph) or less

      Powertrain > Engine and ECT > Active Test

      Active Test Display

      Control the Shift Position

      Data List Display

      Shift Status
      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.

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

      Tip:

      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

      System Condition

      ECM Gear Shift Command

      Proceed to

      1st

      2nd

      3rd

      4th

      5th

      6th

      Malfunction

      Shift solenoid valve SL1 Stuck ON

      1st

      2nd

      3rd

      4th

      4th

      4th

      A

      Shift solenoid valve SL1 Stuck OFF

      N*1

      N*1

      N*1

      N*1

      5th

      6th

      Shift solenoid valve SL2 Stuck ON

      4th

      4th

      4th

      4th

      5th

      6th

      B

      Shift solenoid valve SL2 Stuck OFF

      1st

      2nd

      3rd

      1st

      N*1

      N*1

      Shift solenoid valve SL3 Stuck ON

      2nd

      2nd

      3rd

      4th

      5th

      6th

      C

      Shift solenoid valve SL3 Stuck OFF

      1st

      1st

      3rd

      4th

      5th

      N*1

      Shift solenoid valve SL4 Stuck ON*3

      3rd

      3rd

      3rd

      4th

      5th

      5th

      D

      Shift solenoid valve SL4 Stuck OFF

      1st

      2nd

      1st

      4th

      N*1

      6th

      Shift solenoid valve SLT Stuck ON

      N*2

      N*2

      N*2

      N*2

      N*2

      N*2

      E

      Shift solenoid valve SLT Stuck OFF*3

      1st

      2nd

      3rd

      4th

      5th

      6th
      Tip:

      • *1: Neutral

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

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

    A

    GO TO DTC P0746

    Click here

    B

    GO TO DTC P0776

    Click here

    C

    GO TO DTC P0796

    Click here

    E

    GO TO DTC P2714

    Click here

    D

  3. INSPECT SHIFT SOLENOID VALVE SL4

    1. C197715C14

      *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. Apply 12 V battery voltage to the shift solenoid valve and check that the valve moves and makes an operating noise.

      OK

      Measurement Condition

      Specified Condition

      • Battery positive (+) with a 21 W bulb → Terminal 1

      • Battery negative (-) → Terminal 2

      Valve moves and makes an operating noise

    Result

    Proceed to

    OK

    NG
    NG

    REPLACE SHIFT SOLENOID VALVE SL4

    Click here

    OK

  4. INSPECT TRANSMISSION VALVE BODY ASSEMBLY

    1. Check the transmission valve body assembly.

      Click here

      OK

      There are no foreign objects on any valve.

    Result

    Proceed to

    OK

    NG
    OK

    REPAIR OR REPLACE AUTOMATIC TRANSAXLE ASSEMBLY

    Click here

    NG

    REPAIR OR REPLACE TRANSMISSION VALVE BODY ASSEMBLY

    Click hereClick here