[Previous][Next]
DTC U0141: ETACS CAN timeout
cautionIf DTC U0141 is set in the heater controller assembly (A/C-ECU), diagnose the CAN main bus line.
cautionWhenever the ECU is replaced, ensure that the communication circuit is normal.
 
 
 
 
DTC SET CONDITION
The heater controller assembly (A/C-ECU) receives air conditioning operation-related signal from the ETACS-ECU via the CAN bus lines. If the heater controller assembly (A/C-ECU) can not receive the air conditioning operation-related signal at all on the ETACS-ECU, DTC U0141 will be set.
 
 
TECHNICAL DESCRIPTION (COMMENT)
Current trouble
  • Connector(s) or wiring harness in the CAN bus lines between the ETACS-ECU and the heater controller assembly (A/C-ECU), the power supply system to the ETACS-ECU, the ETACS-ECU itself, or the A/C-ECU may be faulty.
Past trouble
  • Carry out diagnosis with particular emphasis on connector(s) or wiring harness in the CAN bus lines between the ETACS-ECU and the heater controller assembly (A/C-ECU), and the power supply system to the ETACS-ECU. For diagnostic procedures, refer to "How to treat past trouble" (Refer to GROUP 00 - How to Treat Past Trouble ).
    noteFor a past trouble, you can not find it by the M.U.T.-IIISE CAN bus diagnostics even if there is any failure in CAN bus lines. In this case, refer to GROUP 00, How to Cope with Intermittent Malfunction and check the CAN bus lines. You can narrow down the possible cause of the trouble by referring to the DTC, which is set regarding the CAN communication-linked ECUs (Refer to GROUP 54C - CAN Bus Line Diagnostic Flow ).
 
 
TROUBLESHOOTING HINTS
  • The wiring harness or connectors may have loose, corroded, or damaged terminals, or terminals pushed back in the connector
  • Malfunction of the ETACS-ECU
  • Malfunction of the heater controller assembly (A/C-ECU)
 
 
DIAGNOSIS
STEP 1. Using scan tool (M.U.T.-IIISE), diagnose CAN bus line.
(1)
cautionTo prevent damage to scan tool (M.U.T.-IIISE), always turn 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 the Scan Tool (M.U.T.-IIISE) ."
(2) Turn the electric motor switch to the ON position.
(3) Diagnose the CAN bus line.
(4) Turn the electric motor switch to the OFF position.
Is the CAN bus line found to be normal?
Go to Step 2.
Repair the CAN bus lines (Refer to GROUP 54C, Troubleshooting ).
 
STEP 2. Using scan tool (M.U.T.-IIISE), check whether the other system DTC is set.
Check whether the ETACS-related DTC is set.
Is the DTC set?
Diagnose the ETACS-ECU (Refer to GROUP 54A - ETACS, Troubleshooting ).
Go to Step 3.
 
STEP 3. Using scan tool (M.U.T.-IIISE), check whether the DTC is set again.
Check whether an ETACS "time-out" related DTC is set in other ECUs (Refer to GROUP 54C - CAN-Related Diagnosis Code Table ).
Is the DTC set?
Go to Step 4
Go to Step 5
 
STEP 4. Using scan tool (M.U.T.-IIISE), check whether the DTC is set again.
Recheck the DTC.
(1) Erase the DTC.
(2) Electric motor switch: OFF to ON
(3) Check the DTC.
Is the DTC set?
Replace the ETACS-ECU.
A poor connection, open circuit or other intermittent malfunction in the CAN bus line between the ETACS-ECU and the auto A/C controller assembly (A/C-ECU) (Refer to GROUP 00 - How to Cope with Intermittent Malfunction ).
 
STEP 5. Using scan tool (M.U.T.-IIISE), check whether the DTC is set again.
Recheck the DTC is set.
(1) Erase the DTC.
(2) Electric motor switch: OFF to ON
(3) Check the DTC.
Is the DTC set?
Replace the heater controller assembly (A/C-ECU).
A poor connection, open circuit or other intermittent malfunction in the CAN bus line between the ETACS-ECU and the auto A/C controller assembly (A/C-ECU) (Refer to GROUP 00 - How to Cope with Intermittent Malfunction ).