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DTC C1608 EEPROM Fail
 
 
caution
  • If there is any problem in the CAN bus lines, an incorrect DTC 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.
 
 
OPERATION
The ASC-ECU sets DTCs and failure information in the EEPROM*.
note*: EEPROM (Electrical Erasable and Programmable ROM)
 
 
 
DTC SET CONDITIONS
  • This DTC is set when the failure information stored in the EEPROM is not reliable. The failure information stored in the past is not output, and only this DTC is set.
  • This DTC may occur when ASC-ECU power supply shutdown or drop between ASC-ECU is writing a data to the EEPROM.
 
 
 
PROBABLE CAUSES
  • Disconnection of the ASC-ECU connector or the battery terminal when the ignition switch is ON
  • Loose battery terminal
  • Abnormality in battery
  • Damaged wiring harness and connectors
  • ASC-ECU malfunction
 
 
 
 
DIAGNOSIS
Required Special Tools:
  • MB991223: Harness Set
  • MB992006: Extra Fine Probe
STEP 1. Using scan tool (M.U.T.-IIISE), diagnose the CAN bus line.
(1)
cautionTo prevent damage to scan tool (M.U.T.-IIISE), always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool (M.U.T.-IIISE).
Connect scan tool (M.U.T.-IIISE). Refer to "How to connect the Scan Tool (M.U.T.-IIISE) ."
(2) Turn the ignition switch to the "ON" position.
(3) Diagnose the CAN bus line.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Is the check result normal?
Go to Step 3.
Repair the CAN bus lines (Refer to GROUP 54C - CAN Bus Diagnostics Table ). On completion, go to Step 2.
 
STEP 2. DTC recheck after resetting CAN bus lines.
Is DTC C1608 set?
Go to Step 3.
The procedure is complete.
 
STEP 3. Battery check.
Refer to GROUP 54A - Battery Test .
Is the battery in good condition?
Go to Step 5.
Go to Step 4.
 
STEP 4. Charging system check.
Refer to GROUP 16 - On-vehicle Service/Generator Output Line Voltage Drop Test .
Is the charging system in good condition?
Replace the battery (Refer to GROUP 54A - Battery ).
Repair or replace the generator (Refer to GROUP 16 - Generator ).
 
STEP 5. Voltage measurement at the ASC-ECU connector.
(1) Disconnect the connector, and measure at the wiring harness side.
(2) Measure the voltage between the +BV terminal and the body ground.
OK: Approximately system voltage
Is the check result normal?
Go to Step 7.
Go to Step 6.
 
STEP 6. Check of short to power supply, short to ground, and open circuit in +BV line between fusible link and ASC-ECU connector.
Is the check result normal?
Go to Step 7.
: Repair the fusible link, connector(s) or wiring harness.
 
STEP 7. Resistance measurement at ASC-ECU connector.
(1) Disconnect the connector, and measure at the wiring harness side.
(2) Resistance between the GND1 terminal and the body ground, and between the GND2 terminal and the body ground.
OK: Continuity exists (2 Ω or less)
Is the check result normal?
Go to Step 9.
Go to Step 8.
 
STEP 8. Check of open circuit in GND1, GND2 line between ASC-ECU connector and body ground.
Is the check result normal?
Go to Step 9.
: Repair the connector(s) or wiring harness.
 
STEP 9. Check whether the DTC is set again.
(1) Erase the DTC.
(2) Drive the vehicle at 20 km/h (12 mph) or higher.
noteThe ABS warning light does not turn OFF in some cases unless the vehicle runs at 20 km/h (12 mph) or higher.
Is DTC C1608 set?
Replace the hydraulic unit (integrated with ASC-ECU) (Refer to ).
Go to Step 10.
 
STEP 10. Check whether the DTC is set again.
(1) Erase the DTC.
(2) Drive the vehicle at 20 km/h (12 mph) or higher.
noteThe ABS warning light does not turn OFF in some cases unless the vehicle runs at 20 km/h (12 mph) or higher.
Is any DTC set?
Carry out the applicable troubleshooting for the DTC (Refer to ).
: The procedure is complete.