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DTC B1731: PCM/PHEV authentification T/out
 
 
caution
  • When the DTC No. B1731 is stored, be sure to diagnose the CAN bus line.
  • When replacing the ECU, always check that the communication circuit is normal.
 
 
DIAGNOSIS FUNCTION
ETACS-ECU checks if the data from the engine control module (ECM) is received via the CAN bus line. When ETACS-ECU cannot receive the ECM data, it stores the DTC No. B1731.
 
 
TROUBLE JUDGMENT
ETACS-ECU determines that the abnormality is present, if it cannot receive the data from the ECM via the CAN bus line when the ignition switch is turned ON.
 
 
TROUBLESHOOTING HINTS
  • The CAN bus line may be defective
  • The wiring harness or connectors may have loose, corroded, or damaged terminals, or terminals pushed back in the connectors
  • The ECM may be defective
  • The ETACS-ECU may be defective
 
 
DIAGNOSIS
STEP 1. Recheck for diagnostic trouble code.
Recheck if the DTC is stored in ETACS-ECU.
(1)
cautionTo prevent damage to scan tool (M.U.T.-III), always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool (M.U.T.-III).
Connect scan tool (M.U.T.-III). Refer to "How to connect the Scan Tool (M.U.T.-III) ."
(2) Erase the DTC.
(3) Remove the ignition key from key cylinder and insert it again then turn the ignition switch from the Lock (OFF) position to the ON position.
(4) On completion, check that the DTC is not stored again.
Is the DTC stored?
Go to Step 2.
There is an intermittent malfunction such as poor engaged connector(s) or open circuit (Refer to GROUP 00, How to Cope with Intermittent Malfunction ).
 
STEP 2. Using scan tool (M.U.T.-III), diagnose the CAN bus line
(1) Connect scan tool (M.U.T.-III). Refer to "How to connect the Scan Tool (M.U.T.-III) ."
(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 CAN bus line found to be normal?
Go to Step 3.
Repair the CAN bus line (Refer to GROUP 54C - Diagnosis ). On completion, go to Step 3.
 
STEP 3. Using scan tool (M.U.T.-III), read the engine system diagnostic trouble code
Check whether an engine system DTC is stored.
Is the DTC stored?
Perform troubleshooting for the engine (Refer to GROUP 13A - DTC Chart <2.4 L ENGINE>, GROUP 13B - DTC Chart <3.0 L ENGINE>).
Go to Step 4.
 
STEP 4. Using scan tool (M.U.T.-III), read the ETACS diagnostic trouble code.
Check if DTC No.U0100 stored in ETACS-ECU.
Is the DTC stored?
Go to Step 6.
Go to Step 5.
 
STEP 5. Recheck for diagnostic trouble code.
Recheck if the DTC is stored in ETACS-ECU.
(1) Remove the ignition key from key cylinder and insert it again then turn the ignition switch from the Lock (OFF) position to the ON position.
(2) Check if the DTC is stored.
Is the DTC stored?
Replace ETACS-ECU and register the ID codes (Refer to ).
Intermittent malfunction is suspected (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunction ).
 
STEP 6. Recheck for diagnostic trouble code.
Recheck if the DTC is stored in ETACS-ECU.
(1) Remove the ignition key from key cylinder and insert it again then turn the ignition switch from the Lock (OFF) position to the ON position.
(2) Check if the DTC is stored.
Is the DTC stored?
Replace the ECM and register the chassis number and key codes [Refer to GROUP 00 - How to Perform Chassis Number (Chassis No.) Writing ].
The diagnosis is complete.