54C-DIAGNOSTICS ITEM 13

Diagnostic Item 13: Diagnose when the scan tool cannot receive the data sent by ETACS-ECU.

caution

When servicing a CAN bus line, ground yourself by touching a metal object such as an unpainted water pipe. If you fail to do, a component connected to the CAN bus line may be broken.
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. (If the encrypted code is not registered, the engine cannot be started. Register the encrypted code as described in GROUP 54A, Immobilizer System - How to Register Key ID .)

FUNCTION

The diagnostic result demonstrates that "the scan tool (M.U.T.-III) cannot receive the sent data from the ETACS-ECU" when the scan tool (M.U.T.-III) checks the periodically sent data from each ECU and cannot receive the ETACS-ECU data only.

TROUBLE JUDGMENT CONDITIONS

Scan tool (M.U.T.-III) judges the trouble when the periodically sent data from ETACS-ECU cannot be received.

TROUBLESHOOTING HINTS

Damaged harness wires and connectors
Power supply circuit malfunction of the ETACS-ECU
Malfunction of the ETACS-ECU

DIAGNOSIS

STEP 1. Connector check: joint connector (CAN3) and ETACS-ECU connector

caution

The strand end of the twist wire should be within 10 cm from the connector. For details refer to

When checking the joint connector, ensure that its wiring harness side and its short pins are not damaged.

Is the check result normal?

Go to Step 2

Repair the defective connector. Replace the joint connector as necessary.

STEP 2. Resistance measurement at joint connector (CAN3) and ETACS-ECU connector.

caution

A digital multimeter should be used. For details refer to

caution

The test wiring harness should be used. For details refer to

(1) Disconnect the joint connector (CAN3) and the ETACS-ECU connector, and measure at the wiring harness side.

(2) Turn the ignition switch to the LOCK (OFF) position.

(3)

caution

When measuring the resistance, disconnect the negative battery terminal. For details refer to

Ensure that the negative battery terminal is disconnected.

(4) Continuity between joint connector (CAN3) terminal No.11 and ETACS-ECU connector terminal No.19

OK: Continuity (2 ohms or less)

(5) Continuity between joint connector (CAN3) terminal No.22 and ETACS-ECU connector terminal No.18

OK: Continuity (2 ohms or less)

caution

Strictly observe the specified wiring harness repair procedure. For details refer to

Is the check result normal?

<All the resistances measure 2 ohms or less> Go to Step 3

: <Either or all of the resistances measure more than 2 ohms> Repair the wiring harness between joint connector (CAN3) and the ETACS-ECU connector.

STEP 3. Resistance measurement at ETACS-ECU connector.

caution

A digital multimeter should be used. For details refer to

(1) Remove the ETACS-ECU, and measure at the equipment side.

(2) Resistance at ETACS-ECU connector terminal Nos.18 and 19

OK: 120 ± 20 ohms

Is the check result normal?

<Within 120 ± 20 ohms> Power supply to the ETACS-ECU may be suspected. Diagnose the ETACS. Refer to GROUP 54A ETACS - Troubleshooting

<Not within 120 ± 20 ohms> Replace the ETACS-ECU.