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DTC U0154: Occupant Classification-ECU CAN timeout
 
 
caution
  • If DTC B1646 is set in the SRS-ECU, diagnose the CAN main bus line.
  • Whenever the ECU is replaced, ensure that the communication circuit is normal.
 
 
DTC SET CONDITION
When the signals from occupant classification-ECU cannot be received, the SRS-ECU stores DTC U0154.
 
 
JUDGMENT CRITERIA
Because of the CAN-C bus circuit malfunction, if SRS-ECU becomes unable to perform the normal data transmission, SRS-ECU determines that an abnormality is present.
 
 
TROUBLESHOOTING HINTS
  • The CAN bus line may be defective
  • The occupant classification-ECU may be defective
  • The SRS-ECU may be defective
 
 
DIAGNOSIS
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 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 ."
(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 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 occupant classification-ECU DTC.
Check if the DTC is set in the occupant classification-ECU.
Is the DTC set?
Carry out troubleshooting of the occupant classification-ECU or the occupant classification sensor system (Refer to ). Then go to Step 4.
Go to Step 3.
 
STEP 3. Using scan tool (M.U.T.-IIISE), read DTC U0154 for other system.
Check if DTC U0154 is set in ETACS-ECU, combination meter, A/C-ECU.
Is the DTC set?
Replace the passenger seat cushion frame assembly (Refer to GROUP 52A, Front Seat Assembly ).
Go to Step 4.
 
STEP 4. Recheck for DTC.
Check again if the DTC is set.
(1) Erase the DTC.
(2) Turn on the power supply mode of the electric motor switch.
(3) Check if the DTC is set.
(4) Turn off the power supply mode of the electric motor switch.
Is the DTC set?
Replace the SRS-ECU.
There is an intermittent malfunction such as poor engaged connector(s) or open circuit (Refer to GROUP 00, How to use Troubleshooting/inspection Service Points ).