Code No. C1608 EEPROM fail



caution
  • If there is any problem in the CAN bus lines, an incorrect diagnosis code may be stored. Prior to this diagnosis, diagnose the CAN bus lines (Refer to GROUP 54C - CAN Bus Diagnostics Table ).
  • Whenever ECU is replaced, ensure that the CAN bus lines are normal.
  • When the hydraulic unit (integrated with ASC-ECU) is replaced, always carry out the calibration of the steering wheel sensor and the G and yaw rate sensor (Refer to and ).

OPERATION


The ASC-ECU stores the longitudinal sensor calibration and vehicle information in its internal EEPROM *.
note *:EEPROM (Electrically Erasable and Programmable Read Only Memory)

DIAGNOSIS CODE SET CONDITIONS


This code is stored under the cases below:


PROBABLE CAUSES




DIAGNOSIS PROCEDURE


STEP 1. M.U.T.-III CAN bus diagnosis


Use the M.U.T.-III to diagnose the CAN bus lines.

Q. Is the check result normal?

Go to Step 3.
Repair the CAN bus line (Refer to GROUP 54C - Troubleshooting ). On completion, go to Step 2.

STEP 2. Diagnosis code recheck after resetting CAN bus lines


Q. Is diagnosis code No. C1608 stored?

Go to Step 3.
This diagnosis is complete.

STEP 3. Check the battery.


Refer to GROUP 54A - Battery Test .

Q. Is the battery in good condition?

Go to Step 4.
Charge or replace the battery (Refer to GROUP 54A - Battery ). Then go to Step 10.

STEP 4. Check the charging system.


Refer to GROUP 16 - Charging System .

Q. Is the charging system in good condition?

Go to Step 5.
Repair or replace the charging system component(s). Then go to Step 10.

STEP 5. Measure the resistance at the ASC-ECU connector.


(1)Connector check: the ASC-ECU connector, the fuses (relay box) and the fusible links
(2)Disconnect the ASC-ECU connector.
(3)Measure the resistance between +BV terminal and body earth.
OK: No continuity

Q. Is the check result normal?

Go to Step 6.
The power supply circuit may be short. Repair the wiring harness wires or connectors between the ACS-ECU connector +BV terminal and the fusible links, the fuse (relay box) or the fusible links. Then go to Step 10.

STEP 6. Measure the resistance at the ASC-ECU connector.


(1)Connector check: the ASC-ECU connector and the fusible links
(2)Disconnect the ASC-ECU connector and remove the fusible links.
(3)Measure the resistance between +BM terminal and body earth.
OK: No continuity

Q. Is the check result normal?

Go to Step 7.
The power supply circuit may be short. Repair the wiring harness wires or connectors between the ACS-ECU connector +BM terminal and the fusible links, or the fusible links. Then go to Step 10.

STEP 7. Measure the voltage at the ASC-ECU connector.


(1)Disconnect the ASC-ECU connector.
(2)Measure the voltage between +BV terminal and body earth.
OK: Battery voltage

Q. Is the check result normal?

Go to Step 8.
The power supply circuit may be open. Repair the wiring harness wires or connectors between the ACS-ECU connector +BV terminal and the fusible links, the fuse (relay box) or the fusible links. Then go to Step 10.

STEP 8. Measure the voltage at the ASC-ECU connector.


(1)Disconnect the ASC-ECU connector.
(2)Measure the voltage between +BM terminal and body earth.
OK: Battery voltage

Q. Is the check result normal?

Go to Step 9.
The power supply circuit may be open. Repair the wiring harness wires or connectors between the ACS-ECU connector +BM terminal and the fusible links, or the fusible links. Then go to Step 10.

STEP 9. Check whether the diagnosis code is stored again.


Check again if the diagnosis code is stored.
(1)Erase the stored diagnosis code.
(2)Ignition switch: "LOCK" (OFF)
(3)Ignition switch: "ON"

Q. Is diagnosis code No. C1608 stored?

Replace the hydraulic unit (integrated with ASC-ECU) (Refer to ). Then go to Step 10.
The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to Cope with Intermittent Malfunction ).

STEP 10. Check whether the diagnosis code is stored again.


Check again if the diagnosis code is stored.
(1)Erase the set diagnosis code.
(2)Ignition switch: "LOCK" (OFF)
(3)Ignition switch: "ON"

Q. Is diagnosis code No. C1608 stored?

Return to Step 3.
This diagnosis is complete.