CODE NO. U0167 Immobilizer Communication Error <Vehicles without KOS>

caution

If diagnosis code U0167 is set in the engine-ECU, surely perform CAN bus line diagnosis.

caution

Replace ECU after certainly confirming that the communication circuits are normal.

caution

When the ETACS-ECU of vehicles without KOS is replaced, the encrypted code of the ignition key needs to be registered to the ETACS-ECU. <Vehicles with immobilizer system> (If the encrypted code is not registered, the engine cannot be started. Register the encrypted code as described in

TROUBLE JUDGEMENT

Check Conditions

After the engine is cranked.
Ignition switch is "ON" position.

Judgement Criterion

Unable to receive ETACS-ECU (immobilizer) signals through the CAN bus line.

COMMENTS ON TROUBLE SYMPTOM

Current malfunction

The failure is possibly caused by malfunction of the harness and connector in CAN bus line between engine-ECU and ETACS-ECU, by malfunction in the power supply system of ETACS-ECU, in ETACS-ECU itself, in engine-ECU.

Past malfunction

Proceed with troubleshooting focusing on malfunction of the harness and connector in CAN bus line between engine-ECU and ETACS-ECU and malfunction in the power supply system of ETACS-ECU. For diagnosis procedure, refer to how to cope with past malfunctions. (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Treat Past Trouble).

note

In the case of past malfunctions, M.U.T.-III CAN bus line diagnosis cannot detect a malfunction even if there is a malfunction in CAN bus. Therefore, check CAN bus line as in the case of response to intermittent malfunctions (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions). It is possible to narrow down areas with a high possibility of malfunctions from diagnosis codes set in each ECU that performs CAN communication (Refer to GROUP 54C - Explanation about the M.U.T.-III CAN Bus Diagnostics).

FAIL-SAFE AND BACKUP FUNCTION

Immobilises the engine.

PROBABLE CAUSES

Failed harness and connector
Failed ETACS-ECU
Failed engine-ECU

DIAGNOSIS PROCEDURE

STEP 1. M.U.T.-III CAN bus diagnosis

Use M.U.T.-III to perform CAN bus line diagnosis.

Q. Is the check result normal?

	Go to Step 2.

	Repair the CAN bus line (Refer to GROUP 54C - Troubleshooting - CAN Bus Diagnostics Table). After repairing the CAN bus line, go to Step 4.

STEP 2. M.U.T.-III diagnosis code

Confirm whether the diagnosis code is set in the Immobilizer System.

Q. Is diagnosis code set?

	Perform troubleshooting of Immobilizer System (Refer to GROUP 54A - Immobilizer System - Diagnosis Code Chart ).

	Go to Step 3.

STEP 3. M.U.T.-III diagnosis code

Reconfirmation of diagnosis code.

Confirm again whether the diagnosis code is set in the engine-ECU.

Erase the set diagnosis code.
Ignition switch: LOCK (OFF) → ON
Confirm whether the diagnosis code is set.

Q. Is diagnosis code set?

	After replacing engine-ECU, go to Step 4.

	Intermittent malfunction in CAN bus line between engine-ECU and ETACS-ECU (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions).

STEP 4. M.U.T.-III diagnosis code

Reconfirmation of diagnosis code.

Confirm again whether the diagnosis code is set in the engine-ECU.

Erase the set diagnosis code.
Ignition switch: LOCK (OFF) → ON
Confirm whether the diagnosis code is set.

Q. Is diagnosis code set?

	Go to Step 1.

	Check end.