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 in "ON" position.
Battery positive voltage is 8 volts or higher.

Judgement Criterion

Unable to receive KOS-ECU/WCM (immobilizer-ECU) 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/WCM (immobilizer-ECU) 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/WCM (immobilizer-ECU) 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 ).

note

If 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

TROUBLESHOOTING HINTS (The most likely causes for this code to be set are:)

CAN line harness damage or connector damage.
KOS-ECU/WCM (immobilizer-ECU) failed.
ECM failed.

DIAGNOSIS

Required Special Tools:

MB991958: Scan tool (M.U.T.-III Sub Assembly)

MB991824: V.C.I.
MB991827: USB Cable
MB991910: Main Harness A

STEP 1. Using scan tool MB991958, diagnose CAN bus line.

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 to the data link connector.
(2)Turn the ignition switch to the "ON" position.
(3)Diagnose CAN bus line.
(4)Turn the ignition switch to the "LOCK" (OFF) position.

Q. Is the CAN bus line normal?

Go to Step 2.

Repair the CAN bus line. Refer to GROUP 54C, Can Bus Diagnostics Table

. Then go to Step 3.

STEP 2. Using scan tool MB991958, 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.

Q. Is the immobilizer-DTC set?

	Refer to Refer to GROUP 42B, Keyless Operation System - Diagnosis Trouble Code Chart <Vehicles with KOS> or GROUP 42C, Wireless Control Module - Diagnosis Trouble Code Chart <Vehicles with WCM> .

	Go to Step 3.

STEP 3. Using scan tool MB991958, 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.

Q. Is DTC U0167 set?

	Replace the ECM. When the ECM is replaced, register the ID code. Refer to GROUP 42B, Diagnosis - ID Code Registration Judgment Table <Vehicles with KOS> or GROUP 42C, Diagnosis - ID Codes Registration Judgment Table <Vehicles with WCM> .

	It can be assumed that this malfunction is intermittent of CAN bus line between ECM and KOS-ECU/WCM (immobilizer-ECU). Refer to GROUP 00, How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions .