If the diagnosis code No. U0151 is set to the ETACS-ECU, always diagnose the CAN bus line.
Before replacing the ECU, ensure that the power supply circuit, the earth circuit and the communication circuit are normal.
When the ETACS-ECU of vehicles without KOS is replaced, the encrypted code of the ignition key needs to be registered to the ETACS-ECU. (If the encrypted code is not registered, the engine cannot be started. Register the encrypted code as described in Immobilizer System - How to Register Key ID .)
DIAGNOSTIC FUNCTION
If the signal from SRS-ECU cannot be received, the ETACS-ECU sets the diagnosis code No. U0151.
JUDGEMENT CRITERIA
After the following statuses continue to be true for 5 seconds, if the communication with the SRS-ECU cannot be established for 2,500 ms or more, the ETACS-ECU determines that a problem has occurred.
No abnormality is present to the network.
Ignition switch is in the ON position.
No abnormality is present to the power supply fuse (IOD fuse), or the odometer value is at 80.5 km or more.
ETACS-ECU system voltage is at 10-16 V.
PROBABLE CAUSES
Malfunction of the SRS-ECU
Malfunction of the ETACS-ECU
Malfunction of the CAN bus
DIAGNOSIS PROCEDURE
STEP 1. M.U.T.-III CAN bus diagnostics
Use the M.U.T.-III to diagnose the CAN bus lines.
Q.
Is the check result normal?
Go to Step 2
Repair the CAN bus line (Refer to GROUP 54C - Troubleshooting ).
STEP 2. M.U.T.-III other system diagnosis code
Check if diagnosis code is set to the SRS-ECU.
Q.
Is the diagnosis code set?
Troubleshoot the SRS air bag (Refer to GROUP 52B - Troubleshooting ).
Go to Step 3
STEP 3. 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 ignition switch from "LOCK" (OFF) position to "ON" position.
(3)Check if diagnosis code is set.
Q.
Is the diagnosis code set?
Replace the SRS-ECU, and then go to Step 4.
The trouble can be an intermittent malfunction such as a poor connection or open circuit in the CAN bus lines between the SRS-ECU and the ETACS-ECU (GROUP 00 - How to use Troubleshooting/inspection Service Points - How to Cope with Intermittent Malfunction ).
STEP 4. 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 ignition 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 then Return to Step 1.
The trouble can be an intermittent malfunction such as a poor connection or open circuit in the CAN bus lines between the SRS-ECU and the ETACS-ECU (GROUP 00 - How to use Troubleshooting/inspection Service Points - How to Cope with Intermittent Malfunction ).
.)
Repair the CAN bus line (Refer to GROUP 54C - Troubleshooting