Inspection Procedure 2: When the engine is started by the Auto Stop & Go (AS&G) System, the sound of the radio with CD player is interrupted.




COMMENT ON TROUBLE SYMPTOM
The communication circuit between the capacitor unit and engine-ECU, the capacitor unit, or the engine-ECU may be faulty. Or due to insufficient charging of the capacitor unit, the voltage during discharge may be inadequate.
note
  • The capacitor unit is charged when the ignition switch is in the "ACC" or "ON" position.
  • The capacitor unit gradually discharges the electricity in the ignition "OFF" position.

PROBABLE CAUSES

  • Damaged wiring harness or connector.
  • Malfunction of the engine-ECU.
  • Malfunction of the capacitor unit.

DIAGNOSIS PROCEDURE

STEP 1. M.U.T.-III actuator test
Carry out the actuator test for the engine-ECU, and check for the operation of the discharging relay in the capacitor unit.
(1)Start the engine.
(2)Turn all the electrical equipment to "OFF", and wait for 10 minutes.



(3)Remove the front seat assembly (left side). With the connector connected, connect the tester so that the voltage of the capacitor unit connector C-40 (terminal 3) can be measured.
(4)With the radio with CD player "ON", turn the radio on or play a CD for sound output.
(5)Using M.U.T.-III, carry out the actuator test for the engine-ECU, and switch the capacitor unit into discharge.

  • Item 14: Capacitor relay
(6)Check whether the voltage of the capacitor unit connector C-40 (terminal 3) drops several seconds later from the battery voltage before the actuator test of the engine-ECU.

Q. Is the check result normal?

The charging of the capacitor unit is insufficient. Check the trouble symptom again.

Go to Step 2.

STEP 2. M.U.T.-III actuator test
Carry out the actuator test of the engine-ECU, and check for the engine-ECU connector whether the engine-ECU sends the switch signal for discharge to the capacitor unit.
(1)Start the engine.

(2)To measure the voltage of the engine-ECU, refer to the actuator test reference table and prepare the tester. (Refer to GROUP 13A - Troubleshooting, Actuator Test Reference Table <1100> or GROUP 13B - Troubleshooting, Actuator Test Reference Table <1300>)
(3)Using M.U.T.-III, carry out the actuator test for the engine-ECU, and switch the capacitor unit into discharge.

  • Item 14: Capacitor relay
(4)Check if the battery voltage of the engine-ECU A-09 (terminal 135) drastically drops when the Item 14:Capacitor relay is selected for the actuator test of the engine-ECU. (Refer to GROUP 13A - Troubleshooting, Check at the Engine-ECU <1100> or Refer to GROUP 13B - Troubleshooting, Check at the Engine-ECU <1300>)

Q. Is the check result normal?

Go to Step 3.

Go to Step 6.

STEP 3. M.U.T.-III actuator test
Carry out the actuator test of the engine-ECU, and check for the capacitor unit connector whether the engine-ECU sends the switch signal for discharge to the capacitor unit.
(1)Start the engine.


(2)With the connector connected, connect the tester so that the voltage of the capacitor unit connector C-40 (terminal 5) can be measured.
(3)Using M.U.T.-III, carry out the actuator test for the engine-ECU, and switch the capacitor unit into discharge.

  • Item 14: Capacitor relay
(4)Check if the battery voltage of the capacitor unit connector C-40 (terminal 5) drastically drops when the Item 14:Capacitor relay is selected for the actuator test of the engine-ECU.

Q. Is the check result normal?

Go to Step 4.

Replace the capacitor unit.

STEP 4. Connector check: Capacitor unit connector C-40, engine-ECU connector A-09.



Q. Are capacitor unit connector C-40 and engine-ECU connector A-09 connector in good condition?

Go to Step 5.

Repair or replace the damage component(s).

STEP 5. Check the wiring harness between capacitor unit connector C-40 (terminal 5) and engine-ECU connector A-09 (terminal 135).




  • Check the signal line open circuit and short circuit.


note Prior to the wiring harness inspection, check intermediate connector B-117, and repair if necessary.

Q. Are the wiring harnesses between capacitor unit connector C-40 (terminal 5) and engine-ECU connector A-09 (terminal 135) in good condition?

Go to Step 6.

Repair the wiring harness.

STEP 6. Retest the system
(1)Start the engine.
(2)Turn all the electrical equipment to "OFF", and wait for 10 minutes.
(3)With the radio with CD player "ON", turn the radio on or play a CD for sound output.
(4)When the engine is started by the Auto Stop & Go System, check if the sound of the radio with CD player is interrupted.

Q. Is the check result normal?
This diagnosis is complete.
Replace the Engine-ECU.