STOP AND START SYSTEM(for 3ZR-FAE), Diagnostic DTC:P1538

DTC Code DTC Name
P1538 Circuit Malfunction between AT Oil Pump and Stop and Start ECU

DESCRIPTION

The oil pump of the continuously variable transaxle assembly stops operating when the engine is stopped by stop and start control. While the engine is stopped by stop and start control, the oil pump assembly with motor is operated continuously ensuring optimal CVT oil pressure and smooth start-off when the engine is restarted.

The engine stop and start ECU supplies power to the oil pump assembly via terminal OP21 and operates the oil pump assembly with motor in accordance with signals sent from terminal OPM1. The oil pump assembly with motor sends operating speed signals to the engine stop and start ECU via the NOPM signal line.

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

Warning Indicate

Memory

P1538

Circuit Malfunction between AT Oil Pump and Stop and Start ECU

Both of the following conditions are met for 2 seconds or more (1 trip detection logic):

  • Oil pump motor relay circuit in the engine stop and start ECU is off

  • Oil pump assembly with motor power supply malfunction (Oil pump motor relay circuit in the engine stop and start ECU stuck on or shorted) or a short to ground in the NOPM circuit*1

Both of the following conditions are met for 1 second or more (2 trip detection logic):

  • Engine started

  • Oil pump assembly with motor circuit malfunction (Oil pump motor relay in the engine stop and start ECU stuck off, open or short to ground in the OP21, OPM1 or NOPM circuit or an open in the GND circuit)*2

  • Wire harness or connector

  • Oil pump assembly with motor (Continuously variable transaxle assembly)

  • Engine stop and start ECU

Blinks

DTC stored

*1: "Abnormal" is displayed for the freeze frame data item [Status of O/P Signal 1]

*2: "Abnormal" is displayed for the freeze frame data item [Status of O/P Signal 2]

CONFIRMATION DRIVING PATTERN

Tip:

DTCs for the stop and start system are not cleared even if the malfunction has been repaired. After repairing the malfunction, be sure to clear the DTCs.

Click here

  1. CONFIRMATION AFTER TROUBLESHOOTING

    Tip:

    • If the cable is disconnected from the negative (-) battery terminal, stop and start control is prohibited until refresh charge is completed. In this case, drive the vehicle approximately 5 to 60 minutes until refresh charge is completed and stop and start control operation is permitted.

    • Allow the engine to idle for 3 minutes after it is warmed up and check that the engine idle speed is within 50 rpm of the target idle speed.

    1. Connect the GTS to the DLC3.

    2. Turn the ignition switch to ON and turn the GTS on.

    3. Clear the DTCs.

      Click here

      Powertrain > Stop and Start > Clear DTCs

    4. Start the engine and warm it up.

    5. Drive the vehicle at 7 km/h (4.3 mph) or more.

      CAUTION:

      When performing Confirmation Driving Pattern, obey all speed limits and traffic laws.

    6. Depress the brake pedal and stop the vehicle.

    7. Keep the engine stopped by stop and start control. (Keep the shift lever in D.)

    8. Release the brake pedal with the shift lever in D to start the engine.

    9. Check that no DTCs are output.

      Click here

      Powertrain > Stop and Start > Trouble Codes

  2. STOP AND START SYSTEM OPERATION CHECK

    Tip:

    If the cable is disconnected from the negative (-) battery terminal, stop and start control is prohibited until refresh charge is completed. In this case, drive the vehicle approximately 5 to 60 minutes until refresh charge is completed and stop and start control operation is permitted.

    1. Start the engine and warm it up.

    2. Turn the air conditioning system off.

    3. Drive the vehicle at 7 km/h (4.3 mph) or more.

      CAUTION:

      When performing Confirmation Driving Pattern, obey all speed limits and traffic laws.

    4. Depress the brake pedal and stop the vehicle.

    5. Allow the engine to stop by stop and start control. (Keep the shift lever in D.)

    6. Release the brake pedal with the shift lever in D to start the engine.

WIRING DIAGRAM

A337511E05

CAUTION / NOTICE / HINT

Note:

  • When replacing the engine stop and start ECU with a new one, make sure to download the previous status (number of starter operations) of the old engine stop and start ECU. After replacing the engine stop and start ECU, turn the ignition switch to ON and wait 20 seconds, then confirm that "OK" is displayed for the Data List item "Oper Prohibition (O/P Air Bleeding)". Then upload the previous status (number of starter operations) to the engine stop and start ECU.

    Click here

  • After replacing the engine stop and start ECU or air conditioning amplifier assembly, reset and perform learning of the air conditioning information in the engine stop and start ECU.

    Click here

  • After replacing the engine stop and start ECU or airbag sensor assembly, clear and calibrate the deceleration sensor zero point in the engine stop and start ECU.

    Click here

  • Bleed the oil pump assembly with motor (continuously variable transaxle assembly) after removing and installing the continuously variable transaxle assembly or replacing the CVT fluid.

    Click here

Tip:

Using the GTS, read the freeze frame data before troubleshooting. System condition information is recorded as freeze frame data the moment a DTC is stored. This information can be useful when troubleshooting.

Click here

PROCEDURE

  1. CHECK FREEZE FRAME DATA

    Note:

    The freeze frame data is cleared when DTCs are cleared. Be sure to make a note of necessary data in advance.

    1. According to the display on the GTS, select DTC P1538 and check the sets of freeze frame data.

      Click here

      Result

      Tester Display

      Result

      Proceed to

      Status of O/P Signal 1

      Abnormal

      A

      Status of O/P Signal 2

      Abnormal

      B
    B

    PERFORM ACTIVE TEST USING GTS (AT OIL PUMP (LO))Click here

    A

  2. CHECK HARNESS AND CONNECTOR (ENGINE STOP AND START ECU - OIL PUMP ASSEMBLY WITH MOTOR)

    1. Disconnect the A86 and A66 engine stop and start ECU connectors.

    2. Disconnect the B92 oil pump assembly with motor (continuously variable transaxle assembly) connector.

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

      Standard Resistance

      Tester Connection

      Condition

      Specified Condition

      A66-27 (NOPM) - B92-2 (OPST)

      Always

      Below 1 Ω

      A86-6 (OP21) - B92-4 (+B)

      Always

      Below 1 Ω

      A66-27 (NOPM) - Body ground

      Always

      10 kΩ or higher

      B92-2 (OPST) - Body ground

      Always

      10 kΩ or higher

      A86-6 (OP21) - Body ground

      Always

      10 kΩ or higher

      B92-4 (+B) - Body ground

      Always

      10 kΩ or higher

    Result

    Proceed to

    OK

    NG
    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  3. CHECK ENGINE STOP AND START ECU (NOPM TERMINAL VOLTAGE)

    A375352C01

    *a

    Component with harness connected

    (Engine Stop and Start ECU)

    -

    -

    1. Disconnect the B92 oil pump assembly with motor (continuously variable transaxle assembly) connector.

    2. Turn the ignition switch to ON.

    3. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection

      Condition

      Specified Condition

      A66-27 (NOPM) - A66-6 (DGND)

      Ignition switch ON

      10 to 14 V

    Result

    Proceed to

    OK

    NG
    OK

    REPLACE CONTINUOUSLY VARIABLE TRANSAXLE ASSEMBLY

    Click here

    NG

    REPLACE ENGINE STOP AND START ECU

    Click here

  4. PERFORM ACTIVE TEST USING GTS (AT OIL PUMP (LO))

    1. Drive the vehicle to warm up the engine and CVT fluid.

      Tip:

      The oil pump assembly with motor (continuously variable transaxle assembly) may not operate properly if the CVT fluid temperature is low. Make sure to warm up the CVT fluid before performing the Active Test. (CVT fluid temperature: 25°C (77°F) or higher)

    2. Connect the GTS to the DLC3.

    3. Turn the ignition switch to ON.

      Tip:

      Do not start the engine.

    4. Turn the GTS on.

    5. Enter the following menus: Powertrain / Stop and Start / Active Test / AT Oil Pump (Lo).

      Powertrain > Stop and Start > Active Test

      Tester Display

      AT Oil Pump (Lo)

    6. Check the operating sound of the oil pump assembly with motor (continuously variable transaxle assembly) while performing the Active Test.

      Standard

      AT Oil Pump (Lo)

      Result

      ON

      Operating sound can be heard

      OFF

      Operating sound cannot be heard

    Result

    Proceed to

    OK

    NG
    NG

    CHECK HARNESS AND CONNECTOR (ENGINE STOP AND START ECU - OIL PUMP ASSEMBLY WITH MOTOR)Click here

    OK

  5. CHECK ENGINE STOP AND START ECU (NOPM TERMINAL WAVEFORM)

    A375352C01

    *a

    Component with harness connected

    (Engine Stop and Start ECU)

    -

    -

    1. Connect an oscilloscope to the A66-27 (NOPM) and A66-6 (DGND) terminals of the engine stop and start ECU connector.

    2. Enter the following menus: Powertrain / Stop and Start / Active Test / AT Oil Pump (Lo).

      Powertrain > Stop and Start > Active Test

      Tester Display

      AT Oil Pump (Lo)
    3. A112562E03

      Check the waveform while performing the Active Test.

      Item

      Condition

      Tester Connection

      A66-27 (NOPM) - A66-6 (DGND)

      Tool Setting

      5 V/DIV., 5 ms./DIV.

      Condition

      • Ignition switch ON (engine is stopped)

      • Active Test "AT Oil Pump (Lo)" being performed

      Standard

      The waveform is similar to that shown in the illustration with no noise.

    Result

    Proceed to

    OK

    NG
    OK

    REPLACE ENGINE STOP AND START ECU

    Click here

    NG

  6. CHECK OIL PUMP ASSEMBLY WITH MOTOR (OPST TERMINAL VOLTAGE)

    1. A319122C05

      *a

      Front view of wire harness connector

      (to Oil Pump Assembly with Motor (Continuously Variable Transaxle Assembly))

      Disconnect the oil pump assembly with motor (continuously variable transaxle assembly) connector.

    2. Turn the ignition switch to ON.

    3. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection

      Condition

      Specified Condition

      B92-2 (OPST) - B92-1 (GND)

      Ignition switch ON

      10 to 14 V

    Result

    Proceed to

    OK

    NG
    OK

    REPLACE CONTINUOUSLY VARIABLE TRANSAXLE ASSEMBLY

    Click here

    NG

  7. CHECK HARNESS AND CONNECTOR (ENGINE STOP AND START ECU - OIL PUMP ASSEMBLY WITH MOTOR)

    1. Disconnect the A66 engine stop and start ECU connector.

    2. Disconnect the B92 oil pump assembly with motor (continuously variable transaxle assembly) connector.

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

      Standard Resistance

      Tester Connection

      Condition

      Specified Condition

      A66-27 (NOPM) - B92-2 (OPST)

      Always

      Below 1 Ω

      A66-27 (NOPM) - Body ground

      Always

      10 kΩ or higher

      B92-2 (OPST) - Body ground

      Always

      10 kΩ or higher

    Result

    Proceed to

    OK

    NG
    OK

    REPLACE ENGINE STOP AND START ECU

    Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

  8. CHECK HARNESS AND CONNECTOR (ENGINE STOP AND START ECU - OIL PUMP ASSEMBLY WITH MOTOR)

    1. Disconnect the A86 engine stop and start ECU connector.

    2. Disconnect the B92 oil pump assembly with motor (continuously variable transaxle assembly) connector.

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

      Standard Resistance

      Tester Connection

      Condition

      Specified Condition

      A86-6 (OP21) - B92-4 (+B)

      Always

      Below 1 Ω

      A86-6 (OP21) - Body ground

      Always

      10 kΩ or higher

      B92-4 (+B) - Body ground

      Always

      10 kΩ or higher

    Result

    Proceed to

    OK

    NG
    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  9. CHECK HARNESS AND CONNECTOR (OIL PUMP ASSEMBLY WITH MOTOR - BODY GROUND)

    1. Disconnect the B92 oil pump assembly with motor (continuously variable transaxle assembly) connector.

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

      Standard Resistance

      Tester Connection

      Condition

      Specified Condition

      B92-1 (GND) - Body ground

      Always

      Below 1 Ω

    Result

    Proceed to

    OK

    NG
    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  10. CHECK ENGINE STOP AND START ECU (OP21 TERMINAL VOLTAGE)

    A375352C02

    *a

    Component with harness connected

    (Engine Stop and Start ECU)

    -

    -

    1. Disconnect the B92 oil pump assembly with motor (continuously variable transaxle assembly) connector.

    2. Connect the GTS to the DLC3.

    3. Turn the ignition switch to ON.

      Tip:

      Do not start the engine.

    4. Turn the GTS on.

    5. Enter the following menus: Powertrain / Stop and Start / Active Test / AT Oil Pump (Lo).

      Powertrain > Stop and Start > Active Test

      Tester Display

      AT Oil Pump (Lo)

    6. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection

      Condition

      Specified Condition

      A86-6 (OP21) - A66-6 (DGND)

      • Ignition switch ON (engine is stopped)

      • Active Test "AT Oil Pump (Lo)" being performed

      10.5 to 16 V

    Result

    Proceed to

    OK

    NG
    NG

    REPLACE ENGINE STOP AND START ECU

    Click here

    OK

  11. CHECK HARNESS AND CONNECTOR (ENGINE STOP AND START ECU - OIL PUMP ASSEMBLY WITH MOTOR)

    1. Disconnect the A66 engine stop and start ECU connector.

    2. Disconnect the B92 oil pump assembly with motor (continuously variable transaxle assembly) connector.

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

      Standard Resistance

      Tester Connection

      Condition

      Specified Condition

      A66-9 (OPM1) - B92-3 (SI)

      Always

      Below 1 Ω

      A66-9 (OPM1) - Body ground

      Always

      10 kΩ or higher

      B92-3 (SI) - Body ground

      Always

      10 kΩ or higher

    Result

    Proceed to

    OK

    NG
    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  12. CHECK OIL PUMP ASSEMBLY WITH MOTOR (OPM1 TERMINAL WAVEFORM)

    A375352C03

    *a

    Component with harness connected

    (Engine Stop and Start ECU)

    -

    -

    1. Connect an oscilloscope to the A60-9 (OPM1) and A60-6 (DGND) terminals of the engine stop and start ECU connector.

    2. Connect the GTS to the DLC3.

    3. Turn the ignition switch to ON.

      Tip:

      Do not start the engine.

    4. Turn the GTS on.

    5. Enter the following menus: Powertrain / Stop and Start / Active Test / AT Oil Pump (Lo).

      Powertrain > Stop and Start > Active Test

      Tester Display

      AT Oil Pump (Lo)
    6. A329962E01

      Check the waveform while performing the Active Test.

      Item

      Condition

      Tester Connection

      A66-9 (OPM1) - A66-6 (DGND)

      Tool Setting

      5 V/DIV., 5 ms./DIV.

      Condition

      • Ignition switch ON (engine is stopped)

      • Active Test "AT Oil Pump (Lo)" being performed

      Standard

      The waveform is similar to that shown in the illustration with no noise.

    Result

    Proceed to

    OK

    NG
    OK

    REPLACE ENGINE STOP AND START ECU

    Click here

    NG

    REPLACE CONTINUOUSLY VARIABLE TRANSAXLE ASSEMBLY

    Click here