Before replacing the ECU, ensure that the power supply
circuit, the earth circuit and the communication circuit are normal.
TROUBLE JUDGMENT
When voltage at the power supply fuses (fuse Nos. 25
and 26) drops below 5 V with the electric motor switch ON and ACC OFF signal is detected for
500 milliseconds, the ETACS-ECU sets diagnosis code No. B1762.
When voltage at the ECU fuse (fuse No. 26) drops below 5 V with the electric motor
switch ON and ACC ON signal is detected for 500 milliseconds, the ETACS-ECU sets diagnosis code
No. B1765.
PROBABLE CAUSES
Malfunction of fuse No. 25
Malfunction of fuse No. 26
Malfunction of the ETACS-ECU
Damaged harness wires and connectors
DIAGNOSIS PROCEDURE
STEP 1. Check the power supply fuses (fuse Nos. 25 and 26)
Check the power supply fuses (fuse Nos. 25 and 26). (Refer to GROUP 00 - How
to Use Troubleshooting/Inspection Service Points - Inspection Service Points
for a Blown Fuse .)
STEP 3. Check the wiring harness between B-304 ETACS-ECU connector
terminal No. 20 and fusible link (25).
Check the power supply line for open circuit.
note
Before the wiring harness check, check the B-310 junction block connector, and repair
if necessary.
Q.
Is the check result normal?
Go to Step 4.
Repair the wiring harness. Then go to Step 5.
STEP 4. Wiring harness check between B-317 ETACS-ECU connector terminal
No. 74 and the electric motor switch (ACC)
Check the power supply line for open circuit.
note
Before the wiring harness check, check the B-302, B-303 junction block connectors, and
repair if necessary.
Q.
Is the check result normal?
Go to Step 5.
Repair the wiring harness. Then go to Step 5.
STEP 5. Check whether the diagnosis code is reset.
Check again if the diagnosis code is set to the ETACS-ECU.
(1)Erase the diagnosis code.
(2)Turn the electric motor switch from "LOCK" (OFF) position to "ON" position.
(3)Check if diagnosis code is set.
Q.
Is the diagnosis code set?
Replace the ETACS-ECU and register the ID codes (Refer to ).
If the trouble symptom is resolved, an intermittent malfunction such as poorly
engaged connector(s) or wiring harness is suspected. (Refer to GROUP 00 - How to Use
Troubleshooting/Inspection Service Points - How to Cope with Intermittent
Malfunction .)
)
)
)
)
.)
Go to Step 2.
Then go to Step 5.