CAUTIONCOMMENTS ON TROUBLE SYMPTOM
The downshift inhibitor buzzer (incorporated in the ETACS-ECU) will sound if the ETACS-ECU
receives buzzer signal from the engine-A/T-ECU while the ignition switch (IG1) signal
is on. If this function does not work normally, the input signal circuit from the engine-A/T-ECU,
the engine-A/T-ECU itself or the ETACS-ECU may be defective.POSSIBLE CAUSES
- Malfunction of the door switches
- Malfunction of the engine-A/T-ECU
- Malfunction of the ETACS-ECU
- Damaged harness wires and connectors
DIAGNOSIS PROCEDURE
Step 2. MUT-II actuator test
).OK: When actuator test item No.15 is executed, the downshift inhibitor buzzer sounds.
Q: Is the check result normal?
YES:
The trouble can be an intermittent malfunction (Refer to GROUP 00 -
How
to Cope with Intermittent Malfunction ).NO: Go to Step 3
.Step 3. ECU check on the SWS monitor
- Ignition switch: ON
ECUS TO BE CHECKED
- ETACS ECU
OK: "OK" is displayed on the "ETACS ECU" menu.
Q: Is the check result normal?
YES:
Go to Step 4.NO: Refer to Inspection Procedure A-3 "Communication with the ETACS-ECU is not possible"
.Step 4. Confirm communication data by using the SWS monitor.
<Selected item>
ETACS
- Ignition switch: ON
| Item No. |
Item name |
Normal conditions |
|---|---|---|
| Item 30 |
Ignition switch (IG1) |
ON |
OK: Normal condition is displayed.
Q: Is the check result normal?
YES:
Go to Step 5.NO: Refer to inspection procedure P-2 "The ignition switch (IG1) signal is not received"
.Step 6. Check at the C-109 engine-A/T-ECU connector.
- Disconnect the connector, and check at the wiring harness side.
- Ignition switch: ON
- Connect C-109 engine-A/T-ECU connector terminal No.128 to body earth.
OK: The ETACS-ECU buzzer sounds.
Q: Is the check result normal?
YES:
Go to Step 10.NO: Go to Step 7
.Step 8. Check the wiring harness between C-109 engine-A/T-ECU
connector terminal No.128 and C-220 ETACS-ECU connector terminal No.43.
NOTE: Prior to the wiring harness inspection, check intermediate connector C-106, and repair
if necessary.
- Check the communication lines for open circuit.
Q: Is the check result normal?
YES:
Go to Step 9.NO: Repair the defective connector.