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DTC B1770: Implausible coding data
 
 
caution
  • When DTC B1770 is set, be sure to diagnose the CAN bus line.
  • When replacing the ECU, always check that the communication circuit is normal.
 
 
DIAGNOSTIC FUNCTION
If incorrect vehicle information data is received, KOS-ECU stores DTC B1770.
 
 
TECHNICAL DESCRIPTION (COMMENT)
If incorrect global coding data is received with the electric motor switch turned ON when the coding confirmation is completed, KOS-ECU determines that there is a problem.
 
 
TROUBLESHOOTING HINTS
  • Malfunction of CAN bus line
  • Malfunction of KOS-ECU
  • Malfunction of ETACS-ECU
 
 
DIAGNOSIS
STEP 1. Using scan tool (M.U.T.-IIISE), diagnose the CAN bus line.
cautionTo prevent damage to scan tool (M.U.T.-IIISE), always turn the power supply mode of the electric motor switch to the OFF before connecting or disconnecting scan tool (M.U.T.-IIISE).
(1) Connect scan tool (M.U.T.-IIISE). Refer to "How to connect the scan tool ."
(2) Turn the electric motor switch to the ON.
(3) Diagnose the CAN bus line.
(4) Turn the electric motor switch to the OFF.
Is the CAN bus line found to be normal?
Go to Step 2.
Repair the CAN bus line (Refer to GROUP 54C, Diagnosis ).
 
STEP 2. Using scan tool (M.U.T.-IIISE), read the other system diagnostic trouble code.
Check if a coding-related DTC is set in the ETACS-ECU.
(1)
cautionTo prevent damage to scan tool (M.U.T.-IIISE), always turn the power supply mode of the electric motor switch to the OFF position before connecting or disconnecting scan tool (M.U.T.-IIISE).
Connect scan tool (M.U.T.-IIISE). Refer to "How to connect scan tool (M.U.T.-IIISE) ."
(2) Erase the DTC.
(3) Turn the power supply mode of the electric motor switch to ON.
(4) Check if DTC is set.
(5) Turn the power supply mode of the electric motor switch to OFF.
Is the DTC set?
Perform troubleshooting for ETACS-ECU (Refer to GROUP 54A - ETACS - Troubleshooting ).
Go to Step 3.
 
STEP 3.Using scan tool (M.U.T.-IIISE), read the diagnostic trouble code.
Check again if the DTC is set in the KOS-ECU.
(1)
cautionTo prevent damage to scan tool (M.U.T.-IIISE), always turn the power supply mode of the electric motor switch to the OFF before connecting or disconnecting scan tool (M.U.T.-IIISE).
Connect scan tool (M.U.T.-IIISE). Refer to "How to connect scan tool (M.U.T.-IIISE) ."
(2) Erase the DTC.
(3) Turn the power supply mode of the electric motor switch to ON.
(4) Check if DTC is set.
(5) Turn the power supply mode of the electric motor switch to OFF.
Is the DTC set?
Check if the coding data is sent for the vehicles with immobilizer function on "non-adaptable" condition. If so, change the immobilizer function into "adaptable", and then go to Step 4.
Intermittent malfunction is suspected (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunction ).
 
STEP 4. Recheck for diagnostic trouble code.
Check again if the DTC is set in the KOS-ECU.
(1) Erase the DTC.
(2) Turn the power supply mode of the electric motor switch from OFF to ON.
(3) Check if DTC is set.
(4) Turn the power supply mode of the electric motor switch to OFF.
Is the DTC set?
Replace KOS-ECU and register the ID codes (Refer to ).
The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to use Troubleshooting/inspection Service Points - How to Cope with Intermittent Malfunction ).