|
INSPECTION PROCEDURE
A-1: Communication with the MUT-II/III is not possible.
|
|  CAUTION
Whenever the ECU is replaced,
ensure that the power supply circuit, the grounding circuit and the communication circuit are
normal.
|
| |
| COMMENTS ON TROUBLE SYMPTOM
It is suspected that the power supply circuit to the ETACS-ECU is defective, or the wiring
harness between the diagnosis connector and the ETACS-ECU or their connector(s) is damaged.
NOTE: If the wiring harness between the ETACS-ECU and body earth is defective, also check C-217
ETACS-ECU connector terminal No.3, and repair if necessary.
|
| POSSIBLE CAUSES
- Malfunction of the ETACS-ECU
- Damaged harness wires and connectors
|
| |
| |
| Step 1. Check that the MUT-II/III communicates
with the other systems.
Use the MUT-II/III to confirm that it communicates with the engine-A/T-ECU.
Q: Is the check result normal?
YES:
Go to Step 2  .
NO:
Diagnose the engine control system by referring to  <4G64>
or <4G69>.
|
| Step 2. Check that the MUT-II/III can communicate with the system.
When the ignition switch is turned ON, check if the MUT-II/III can communicate
with the system.
Q: Is the check result normal?
YES:
Refer to Inspection Procedure A-2 "Check the ETACS-ECU battery power supply circuit ."
NO:
Go to Step 3 .
|
| Step 3. Connector check: C-219 ETACS-ECU connector Q: Is the check result normal?
YES:
Go to Step 4 .
NO:
Repair the defective connector.
|
| Step 4. Measure the resistance at the C-219 ETACS-ECU connector. - Disconnect the connector, and measure at the junction block side.
- Resistance between C-219 ETACS-ECU connector terminal No.56 and body earth
OK: 2 Ω
or less
Q: Is the check result normal?
YES:
Go to Step 6 .
NO:
Go to Step 5 .
|
| Step 5. Check the wiring harness between C-219 ETACS-ECU connector
terminal No.56 and body earth. - Check the earth wires for open circuit.
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:
Repair the wiring harness.
|
| Step 6. Connector check: C-24 diagnosis connector Q: Is the check result normal?
YES:
Go to Step 7 .
NO:
Repair the defective connector.
|
| Step 7. Check the wiring harness from C-219 ETACS-ECU connector terminal
Nos.51 and 67 to diagnosis connector terminal Nos.9 and 1. - Check the communication lines for open circuit.
Q: Is the check result normal?
YES:
Go to Step 8 .
NO:
Repair the wiring harness.
|
| Step 8. Retest the system.
Check whether the communication with the MUT-II/III is possible.
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:
Replace the ETACS-ECU.
|