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DTC U0167: Immobilizer Communication Error

 
 
caution
  • If the ECM output the DTC U0167, make sure to diagnose the CAN bus line.
  • Before replacing the ECU, make sure that the communication circuit is operating normally.
 
 
DTC SET CONDITIONS
Check Conditions
  • Ignition switch is "ON" position.
  • Battery positive voltage is more than 8 volts.
Judgment Criterion
  • Unable to receive KOS-ECU/ETACS-ECU (immobilizer) signals through the CAN bus line.
 
 
COMMENT
Current Trouble
  • Some of the possible causes are a harness or connector damage between the ECM and the KOS-ECU/WCM (immobilizer-ECU) on the CAN bus line, a failure in the KOS-ECU/ETACS-ECU (immobilizer) power supply system, a failure in the KOS-ECU/WCM (immobilizer-ECU), or a failure in the ECM.
Past Trouble
  • Proceed to troubleshoot based on a harness or connector damage on the CAN bus line between the ECM and KOS-ECU/WCM (immobilizer-ECU), and a failure in the KOS-ECU/ETACS-ECU (immobilizer) power supply system. Refer to "How to cope with past trouble" (Refer to GROUP 00, How to Use Troubleshooting/Inspection Service Points - How to Treat Past Trouble ).
noteIf a malfunction occurred in the past, a failure cannot be discovered through the MB991958 CAN bus diagnosis even if there might be a problem with the CAN bus. In this case, refer to GROUP 00, How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions . Furthermore, it is possible to narrow down the areas of the possible failures from the DTCs that are output by the ECUs, which are communicating on the CAN bus [Refer to GROUP 54C, Explanation about the Scan Tool (M.U.T.-III) CAN Bus Diagnostics ].
 
 
FAIL-SAFE AND BACKUP FUNCTION
  • Engine start is prohibited.
 
 
TROUBLESHOOTING HINTS (The most likely causes for this code to be stored are:)
  • CAN line harness damage or connector damage.
  • KOS-ECU/ETACS-ECU (immobilizer) failed.
  • ECM failed.

 
 
DIAGNOSIS
Required Special Tools:
  • MB992744: Vehicle communication interface-Lite (V.C.I.-Lite)
  • MB992745: V.C.I.-Lite main harness A
  • MB992747: V.C.I.-Lite USB cable short
  • MB992748: V.C.I.-Lite USB cable long
  • 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 (Vehicles with CAN communication system)
STEP 1. Using scan tool (M.U.T.-III), diagnose CAN bus line.
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).
(1) 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 CAN bus line.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Is the CAN bus line normal?
Go to Step 2.
Repair the CAN bus line. Refer to GROUP 54C, Diagnosis - CAN Bus Diagnostics Table . Then go to Step 4.
 
STEP 2. Using scan tool (M.U.T.-III), read the diagnostic trouble code (DTC).
(1) Turn the ignition switch to the "ON" position.
(2) Read the immobilizer-DTC.
(3) Turn the ignition switch to the "LOCK" (OFF) position.
Is the immobilizer-DTC stored?
Refer to GROUP 42B, Diagnosis - Diagnostic Trouble Code Chart <Vehicles with KOS> or GROUP 54A, Diagnosis - Diagnostic Trouble Code Chart <Vehicles without KOS> .
Go to Step 3.
 
STEP 3. Using scan tool (M.U.T.-III), read the diagnostic trouble code (DTC).
(1) Turn the ignition switch to the "ON" position.
(2) After the MFI-DTC has been deleted, read the MFI-DTC again.
(3) Turn the ignition switch to the "LOCK" (OFF) position.
Is DTC U0167 stored?
Replace the ECM (Refer to, Removal and Installation ). Then go to Step 4.
It can be assumed that this malfunction is intermittent of CAN bus line between ECM and KOS-ECU/ETACS-ECU (immobilizer). Refer to GROUP 00, How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions .
 
STEP 4. Using scan tool (M.U.T.-III), read the diagnostic trouble code (DTC).
(1) Turn the ignition switch to the "ON" position.
(2) After the MFI-DTC has been deleted, read the MFI-DTC again.
(3) Turn the ignition switch to the "LOCK" (OFF) position.
Is DTC U0167 stored?
Retry the troubleshooting.
The inspection is complete.