Code No. U0164: A/C CAN timeout
caution |
- If diagnosis code No. U0164 is set, be sure to diagnose the CAN bus line.
- When replacing the ECU, always check that the communication circuit is normal.
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DIAGNOSIS FUNCTION
If the signal from A/C-ECU cannot be received, the KOS&OSS-ECU sets diagnosis code No. U0164.
PROBABLE CAUSES
- Malfunction of CAN bus line
- Malfunction of A/C-ECU
- Malfunction of KOS&OSS-ECU
DIAGNOSIS PROCEDURE
STEP 1. M.U.T.-III CAN bus diagnostics
Use M.U.T.-III to diagnose the CAN bus lines.
Q.
Is the check result normal?
Go to Step 2.
Repair the CAN bus line (Refer to GROUP 54C - Troubleshooting
).
STEP 2. M.U.T.-III other system diagnosis code
Check if the A/C-ECU related diagnosis code is set.
Q.
Is the diagnosis code set?
Troubleshoot the A/C-ECU (Refer to GROUP 55B - Heater Control Unit, Diagnosis
).
Go to Step 3.
STEP 3. M.U.T.-III other system diagnosis code
Check if diagnosis code No.U0164 is set in the engine-ECU.
Q.
Is the diagnosis code set?
Go to Step 4.
Go to Step 5.
STEP 4. Check whether the diagnosis code is set again.
Recheck if the diagnosis code is set in the KOS&OSS-ECU.
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(1)Erase the diagnosis code.
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(2)Turn the power supply mode of the engine switch from "LOCK (OFF) to "ON".
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(3)Check if the diagnosis code is set.
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Q.
Is the diagnosis code set?
Replace the A/C-ECU (Refer to GROUP 55B - Heater Control Unit
).
A poor connection, open circuit or other intermittent malfunction is present in the CAN bus lines between the A/C-ECU and the KOS&OSS-ECU (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunction
).
STEP 5. Check whether the diagnosis code is set again.
Recheck if the diagnosis code is set.
|
(1)Erase the diagnosis code.
|
|
(2)Turn the power supply mode of the engine switch from "LOCK (OFF) to "ON".
|
|
(3)Check if the diagnosis code is set.
|
Q.
Is the diagnosis code set?
Replace KOS&OSS-ECU and register the ID codes (Refer to
).
A poor connection, open circuit or other intermittent malfunction is present in the CAN bus lines between the A/C-ECU and the KOS&OSS-ECU (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunction
).