Code No.P0942: Electric Oil Pump Status <Vehicles with AS&G system>


DIAGNOSTIC FUNCTION



JUDGMENT CRITERIA




  • More than 1 second passes as the electric oil pump state signal is less than 46%
  • More than 1 second passes as the electric oil pump state signal is more than 54%
note While the electric oil pump is running, the normal state signal sent to the CVT-ECU is approximately 50%.


  • More than 1 second passes as the electric oil pump state signal is less than 26%
  • More than 1 second passes as the electric oil pump state signal is more than 34%
note While the electric oil pump is stopped, the normal state signal sent to the CVT-ECU is approximately 30%.

PROBABLE CAUSES



  • Malfunction of electric oil pump relay
  • Damaged wiring harness and connectors
  • Malfunction of DC/DC converter
  • Malfunction of electric oil pump
  • Malfunction of CVT-ECU

DIAGNOSTIC PROCEDURE

STEP 1. Check electric oil pump relay stand-alone itself.
Refer to .

Q. Is the check result normal?
Go to Step 2.
Replace the electric oil pump relay.

STEP 2. Perform voltage measurement at electric oil pump relay connector (power supply terminal).
(1)Remove the electric oil pump relay, and measure at the wiring harness side.
(2)Measure the voltage between the relay box (power supply terminal) and body earth.
(3)Turn the ignition switch to the "ON" position.
OK: System voltage

Q. Is the check result normal?
Go to Step 5.
Go to Step 3.

STEP 3. Check for open circuit or short to earth in power supply line between the electric oil pump relay connector and the DC/DC converter connector.

Q. Is the check result normal?
Go to Step 4.
Repair the connector(s) or wiring harness.

STEP 4. Symptom recheck after erasing diagnosis code.

Q. Is the check result normal?
Intermittent malfunction.
Replace the DC/DC converter.

STEP 5. Check for open circuit in OPRL line between the electric oil pump relay connector and the CVT-ECU connector.

Q. Is the check result normal?
Go to Step 6.
Repair the connector(s) or wiring harness.

STEP 6. Check for open circuit or short to earth in power supply line between the electric oil pump relay connector and the electric oil pump connector.

Q. Is the check result normal?
Go to Step 7.
Repair the connector(s) or wiring harness.

STEP 7. Check for open circuit in earth line between the electric oil pump connector and the body earth.

Q. Is the check result normal?
Go to Step 8.
Repair the connector(s) or wiring harness.

STEP 8. Perform voltage measurement at electric oil pump connector (power supply terminal).
(1)Disconnect the connector, and measure at the wiring harness side.
(2)Measure the voltage between the electric oil pump connector (power supply terminal) and body earth.
(3)Turn the ignition switch to the "ON" position.
OK: System voltage

Q. Is the check result normal?
Go to Step 10.
Go to Step 9.

STEP 9. Check for open circuit or short to earth in EOPI line between the electric oil pump connector and the CVT-ECU connector.

Q. Is the check result normal?
Replace the CVT-ECU.
Repair the connector(s) or wiring harness.

STEP 10. Perform voltage measurement at CVT-ECU connector (EOPO terminal).

(1)Disconnect the electric oil pump connector and connect as in the figure using the special tool (Test harness: MB991658).
(2)Disconnect the CVT-ECU connector and measure the voltage between EOPO terminal and earth at wiring harness side.
(3)Turn the ignition switch to the "ON" position.
OK: System voltage

Q. Is the check result normal?

Go to Step 12.

Go to Step 11.

STEP 11. Check for open circuit or short to earth in EOPO line between the electric oil pump connector and the CVT-ECU connector.

Q. Is the check result normal?
Replace the electric oil pump. After that, bleed the air from the electric oil pump (Refer to ).
Repair the wiring harness.

STEP 12. M.U.T.-III data list

(1)Disconnect the electric oil pump connector and connect as in the figure using the special tool (Test harness: MB991658).
(2)Item 63: Electric oil pump state signal (Refer to ).

Q. Is the check result normal?

Go to Step 13.

Replace the electric oil pump. After that, bleed the air from the electric oil pump (Refer to ).

STEP 13. Diagnosis code recheck

Q. Is the diagnosis code set?
Replace the CVT-ECU.
Intermittent malfunction.