Inspection Procedure 18: The FCM switch signal is not received.


caution
  • Before replacing the ECU, ensure that the power supply circuit, the earth circuit and the communication circuit are normal.
  • 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 Immobilizer System - How to Register Key ID .)

COMMENTS ON TROUBLE SYMPTOM


If there is an error to the FCM switch input signal, the FCM switch signal is no longer output to the communication line.

PROBABLE CAUSES



DIAGNOSIS PROCEDURE


STEP 1. Check the FCM switch.


Refer to GROUP 35C - FCM ON/OFF switch continuity check .

Q. Is the check result normal?

Go to Step 2

Replace the FCM switch.

STEP 2. Resistance measurement at FCM switch connector (earth terminal)


(1)Disconnect the connector, and measure at the wiring harness side.
(2)Measure the resistance between the FCM switch connector (earth terminal) and body earth.
OK: Continuity exists (2 Ω or less)

Q. Is the check result normal?

Go to Step 4

Go to Step 3

STEP 3. Check of open circuit in earth line between FCM switch connector and body earth


Q. Is the check result normal?

Intermittent malfunction is suspected (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunction ).

Repair the connector(s) or wiring harness.

STEP 4. Check of short to earth, and open circuit in FCMS line between FCM switch connector and ETACS-ECU connector


Q. Is the check result normal?

Go to Step 5

Repair the connector(s) or wiring harness.

STEP 5. M.U.T.-III data list


Check the ETACS-ECU service data.

Item No.
 Item name
 Normal condition
Item 404
 FCM switch
 ON

Item No.
 Item name
 Normal condition
Item 404
 FCM switch
 OFF
OK: Normal condition is displayed.

Q. Is the check result normal?

The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to use Troubleshooting/inspection Service Points - How to Cope with Intermittent Malfunction ).

Replace the ETACS-ECU.