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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 stores 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 set 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.
 
 
 
TROUBLESHOOTING HINTS
  • Disconnection of the ASC-ECU connector or the 12V Starter Battery terminal when the electric motor switch is ON
  • Loose 12V Starter Battery terminal
  • Abnormality in 12V Starter Battery
  • Damaged wiring harness and connectors
  • ASC-ECU malfunction
 
 
 
 
DIAGNOSIS
Required Special Tools:
  • MB991223: Harness Set
  • MB992006: Extra Fine Probe
STEP 1. Scan tool (M.U.T.-IIISE) CAN bus diagnostics.
(1)
cautionTo prevent damage to scan tool (M.U.T.-IIISE), always turn off the power supply mode of the electric motor switch 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 on the power supply mode of the electric motor switch.
(3) Diagnose the CAN bus line.
(4) Turn off the power supply mode of the electric motor switch.
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 No. C1608 set?
Go to Step 3.
The procedure is complete.
 
STEP 3. 12V Starter Battery check.
Refer to GROUP 54A - 12V Starter Battery Test .
Is the 12V Starter Battery in good condition?
Go to Step 4.
Replace the 12V Starter Battery.
 
STEP 4. 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: The voltage should measure approximately 12 volts (battery positive voltage).
Is the check result normal?
Go to Step 6.
Go to Step 5.
 
STEP 5. 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 6.
: Repair the fusible link, connector(s) or wiring harness.
 
STEP 6. 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: The resistance should be 2 ohms or less
Is the check result normal?
Go to Step 8.
Go to Step 7.
 
STEP 7. Check of open circuit in GND1, GND2 line between ASC-ECU connector and body ground.
Is the check result normal?
Go to Step 8.
: Repair the connector(s) or wiring harness.
 
STEP 8. Check whether the DTC is set again.
(1) Erase the DTC.
(2) Drive the vehicle at 12 mph (20 km/h) or higher.
noteThe ABS warning light does not turn OFF in some cases unless the vehicle runs at 12 mph (20 km/h) or higher.
Is DTC No. C1608 set?
Replace the hydraulic unit (integrated with ASC-ECU) (Refer to ).
Go to Step 9.
 
STEP 9. Check the other DTC.
(1) Erase the DTC.
(2) Drive the vehicle at 12 mph (20 km/h) or higher.
noteThe ABS warning light does not turn OFF in some cases unless the vehicle runs at 12 mph (20 km/h) or higher.
Is any DTC set?
Carry out the applicable troubleshooting for the DTC (Refer to ).
: Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/How to Cope with Intermittent Malfunctions ).