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Code No. C1608 EEPROM fail
 
 
caution
  • If there is any problem in the CAN bus lines, an incorrect diagnostic trouble code may be set. 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)
 
 
DIAGNOSTIC TROUBLE CODE SET CONDITIONS
This code is set under the cases below:
  • If the longitudinal sensor calibration and vehicle information, which is stored in the EEPROM, is unfeasible.
 
 
PROBABLE CAUSES
  • Removal of ASC-ECU connector or battery terminal with the ignition switch ON
  • Battery failure
  • Battery terminal looseness
  • Defective battery charger
  • Damaged harness wires and connectors
  • Malfunction of ASC-ECU
 
 
DIAGNOSIS
STEP 1. Using scan tool MB991958, diagnose the CAN bus lines.
Use the scan tool MB991958 to diagnose the CAN bus lines.
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. Diagnostic trouble code recheck after resetting CAN bus lines
Is diagnostic trouble code No. C1608 set?
Go to Step 3.
This diagnosis is complete.
 
STEP 3. Check the battery.
Refer to GROUP 54A, Battery Test .
Is the battery in good condition?
Go to Step 4.
Charge or replace the battery. Then go to Step 5.
 
STEP 4. Check the charging system.
Refer to GROUP 16, Charging System .
Is the charging system in good condition?
Go to Step 5.
Repair or replace the charging system component(s). Then go to Step 5.
 
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 ground.
OK: No continuity
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 9.
 
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 ground.
OK: No continuity
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 9.
 
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 ground.
OK: Battery voltage
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 9.
 
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 ground.
OK: Battery voltage
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 9.
 
STEP 9. Check whether the diagnostic trouble code is set again.
Check again if the diagnostic trouble code is set.
(1) Erase the set diagnostic trouble code.
(2) Ignition switch: "LOCK" (OFF)
(3) Ignition switch: "ON"
Is diagnostic trouble code No. C1608 set?
Replace the hydraulic unit (integrated with ASC-ECU) (Refer to ).
The trouble can be an intermittent malfunction (Refer to GROUP 00, How to Cope with Intermittent Malfunction ).