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DTC U1110: A/C CAN timeout/Not equipped
 
 
caution
  • If DTC No. U1110 is stored in the ETACS-ECU, diagnose the CAN main bus line.
  • Whenever the ECU is replaced, ensure that the power supply circuit, the ground circuit and the communication circuit are normal.
 
 
TROUBLE JUDGMENT
If signal from the A/C-ECU cannot be received for 500 milliseconds or more, the ETACS-ECU stores DTC No. U1110.
 
 
TROUBLESHOOTING HINTS
  • The CAN bus line may be defective.
  • The ETACS-ECU may be defective.
  • The A/C-ECU may be defective.
 
 
DIAGNOSIS
STEP 1. Using scan tool (M.U.T.-III), diagnose the CAN bus line.
(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) 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 2.
Repair the CAN bus line (Refer to GROUP 54C - Troubleshooting ). On completion, go to Step 5.
 
STEP 2. Using scan tool (M.U.T.-III), read the A/C diagnostic trouble code.
Check that the A/C-ECU set a DTC.
Is the DTC stored?
Diagnose the A/C-ECU. Refer to GROUP 55B - Troubleshooting .
Go to Step 3.
 
STEP 3. Recheck for diagnostic trouble code.
Check again if the DTC is stored in the ETACS-ECU.
(1) Erase the DTC.
(2) Turn the ignition switch from "LOCK" (OFF) position to "ON" position.
(3) On completion, check that the DTC is reset.
Is the DTC stored?
Replace the A/C-ECU. After replacing the ECU, carry out the CAN bus diagnostics. Then go to Step 4.
A poor connection, open circuit or other intermittent malfunction is present in the CAN bus lines between the A/C-ECU and the ETACS-ECU (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions ).
 
STEP 4. Recheck for diagnostic trouble code.
Check again if the DTC is stored in the ETACS-ECU.
(1) Erase the DTC.
(2) Turn the ignition switch from "LOCK" (OFF) position to "ON" position.
(3) On completion, check that the DTC is not reset.
Is the DTC stored?
Replace the ETACS-ECU. After replacing the ECU, carry out the CAN bus diagnostics. Then go to Step 5.
A poor connection, open circuit or other intermittent malfunction is present in the CAN bus lines between the A/C-ECU and the ETACS-ECU (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions ).
 
STEP 5. Recheck for diagnostic trouble code.
Recheck if the DTC is stored in the ETACS-ECU.
(1) Erase the DTC.
(2) Turn the ignition switch from "LOCK" (OFF) position to "ON" position.
(3) On completion, check that the DTC is reset.
Is the DTC stored?
Return to Step 1.
The procedure is complete.