Keyless Operation System (KOS)

DTC U0164: A/C-ECU CAN timeout

CAUTION:
- If DTC U0164 is set, be sure to diagnose the CAN bus line.
- When replacing the ECU, always check that the communication circuit is normal.

DIAGNOSTIC FUNCTION
If the signal from A/C-ECU cannot be received, the KOS-ECU sets DTC U0164.

TROUBLESHOOTING HINTS
- The CAN bus line may be defective.
- The A/C-ECU may be defective.
- The KOS-ECU may be defective.

DIAGNOSIS

Required Special Tools:
- MB991958: Scan Tool (M.U.T.-III Sub Assembly)
- MB991824: Vehicles Communication Interface (V.C.I.)
- MB991827: M.U.T.-III USB Cable
- MB991910: M.U.T.-III Main Harness A

STEP 1. Using scan tool MB991958, diagnose the CAN busline






CAUTION: To prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.

1. Connect scan tool MB991958. Refer to "How to connect the Scan Tool (M.U.T.-III)." 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.

Q: Is the CAN bus line found to be normal?

YES: Go to Step 2.

NO: Repair the CAN bus line (Refer to Controller Area Network (CAN), Diagnosis).

STEP 2. Using scan tool MB991958, read the A/C diagnostic trouble code
Check if DTC is set to the A/C-ECU.

Q: Is the DTC set?

YES: Troubleshoot the A/C (Refer to Heater and A/C and Ventilation).

NO: Go to Step 3.

STEP 3. Recheck for diagnostic trouble code.

Check again if the DTC is set to the KOS-ECU.

1. Erase the DTC.
2. Turn the ignition switch from "LOCK" (OFF) position to "ON"position.
3. Check if DTC is set.
4. Turn the ignition switch to the "LOCK" (OFF) position.

Q: Is the DTC set?

YES: Replace KOS-ECU and register the ID codes. (Refer to ID Code Registration Necessity Judgment Table)

NO: The trouble can be an intermittent malfunction (Refer to general (body and chassis) - How to use Troubleshooting/inspection Service Points - How to Cope with Intermittent Malfunction).