Inspection Procedure 1

Inspection Procedure 1: The theft-alarm is not armed (the theft-alarm indicator does not illuminate).

CAUTION:
Before replacing the ECU, ensure that the power supply circuit, the ground circuit and the communication circuit are normal.














TECHNICAL DESCRIPTION (COMMENT)

If this function does not work normally, the input signal circuits to the components below, the theft-alarm indicator, the ETACS-ECU or the CAN bus line may have a problem.

- Keyless entry transmitter
- Key reminder switch
- Ignition switch (ACC)
- Hood latch switch
- Door switches
- Trunk latch switch

TROUBLESHOOTING HINTS

- CAN bus line may be defective
- Theft-alarm indicator may be defective
- Keyless entry transmitter may be defective
- The key reminder switch may be defective
- Door switch may be defective
- Trunk latch switch may be defective
- Hood latch switch may be defective
- The KOS-ECU may be defective
- The WCM may be defective
- The ETACS-ECU may be defective
- The wiring harness or connectors may have loose, corroded, or damaged terminals, or terminals pushed back in the connector

DIAGNOSIS

Required Special Tools:

- MB992006: Extra fine probe
- MB991223: Harness set
- MB991958: Scan Tool (M.U.T.-III Sub Assembly)
- MB991824: Vehicle 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 MB991958, diagnose the CAN bus line.





(1)
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.

Connect scan tool MB991958. Refer to "How to connect the scan tool (M.U.T.-III) Reading and Clearing Diagnostic Trouble Codes."
(2)Turn the ignition switch to the "ON" position.
(3)Diagnose the CAN bus line.
(4)Turn the ignition switch to the "LOCK" (OFF) position.

Q. Is the CAN bus line found to be normal?

YES Go to Step 2.

NO Repair the CAN bus line CAN Bus Diagnostics Chart).

STEP 2. Using scan tool MB991958, check for any diagnostic trouble code.

Check if DTC is set to the KOS-ECU [vehicles with KOS] or WCM [vehicles with WCM].

(1)Turn the ignition switch to the "ON" position.

(2)Check whether the KOS or WCM related DTC is set.

(3)Turn the ignition switch to the "LOCK" (OFF) position.

Q. Is the DTC set?

YES [vehicles with KOS] : Troubleshoot the KOS Keyless Operation System (KOS)).
YES [vehicles with WCM] : Troubleshoot the WCM Wireless Control Module (WCM)).
NO : Go to Step 3.
STEP 3. Check the keyless operation key [KOS] or keyless entry transmitter [WCM].

Check that the doors can be open by keyless operation key [KOS] or keyless entry transmitter [WCM].

Q. is the keyless operation key[ KOS] or keyless entry transmitter[ WCM] normally?

YES Go to Step 4.
NO [vehicles with KOS] : Troubleshoot the KOS Keyless Operation System (KOS)).
NO [vehicles with WCM] : Troubleshoot the WCM Wireless Control Module (WCM)).
STEP 4. Using scan tool MB991958, check data list.

Use the ETACS-ECU data list to check the signals related to the theft-alarm function.

- Turn the ignition switch to the "ACC" position.
- Open the hood.

- Open each door.
- Open the Trunk.





- Close each door.
- Close the Trunk.





- Turn the ignition switch to the "LOCK" (OFF) position (with ignition key[ vehicles with WCM] or emergency key[ vehicles with KOS] inserted).





Q. Does scan tool MB991958 display the items "Dr door ajar switch", "As door ajar switch", "RR door ajar switch", "RL door ajar switch", "Trunk/gate trunk ajar switch" , "Handle lock switch", "Hood switch" and "ACC switch" as normal condition?

YES [Normal conditions are displayed for all items.] : Go to Step 5.
NO [Normal condition is not displayed for item No. 256.] : Troubleshoot the ETACS-ECU. Refer to diagnosis - Inspection Procedure 5 "ETACS-ECU does not receive any signal from the front door switch (LH)" Inspection Procedure 5.
NO [Normal condition is not displayed for item No. 257.] : Troubleshoot the ETACS-ECU. Refer to diagnosis - Inspection Procedure 6 "ETACS-ECU does not receive any signal from the front door switch (RH)" Inspection Procedure 6.
NO [Normal condition is not displayed for item No. 258.] : Troubleshoot the ETACS-ECU. Refer to diagnosis - Inspection Procedure 7 "ETACS-ECU does not receive any signal from the rear door switch (LH)" Inspection Procedure 7.
NO [Normal condition is not displayed for item No. 259.] : Troubleshoot the ETACS-ECU. Refer to diagnosis - Inspection Procedure 8 "ETACS-ECU does not receive any signal from the rear door switch (RH)" Inspection Procedure 8.
NO [Normal condition is not displayed for item No. 260.] : Troubleshoot the ETACS-ECU. Refer to diagnosis - Inspection Procedure 9 "ETACS-ECU does not receive any signal from the trunk lid actuator and switch Inspection Procedure 9.
NO [Normal condition is not displayed for item No. 264.] : Troubleshoot the ETACS-ECU. Refer to diagnosis - Inspection Procedure 3 "ETACS-ECU does not receive any signal from key reminder switch" Inspection Procedure 3.
NO [Normal condition is not displayed for item No. 266.] : Troubleshoot the ETACS-ECU. Refer to Inspection Procedure 10 "ETACS-ECU does not receive any signal from the hood latch switch" Inspection Procedure 10.
NO [Normal condition is not displayed for item No. 288.] : Troubleshoot the ETACS-ECU. Refer to diagnosis - Inspection Procedure 1 "ETACS-ECU does not receive any signal from the ignition switch (ACC) signal" Inspection Procedure 1.
STEP 5. Check center panel unit connector C-124 for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q. Is center panel unit connector C-124 in good condition?

YES Go to Step 6.
NO Repair the damaged parts.
STEP 6. Check the theft-alarm indicator.

Refer to Theft Alarm Inspection.





Q. Is the theft-alarm indicator in good condition?

YES Go to Step 7.

NO Replace the center panel unit.

STEP 7. Check ETACS-ECU connector C-307 for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q. Is the ETACS-ECU connector C-307 in good condition?

YES Go to Step 8.
NO Repair the damaged parts.
STEP 8. Measure the voltage at ETACS-ECU connector C-307.

(1)Disconnect ETACS-ECU connector C-307, and measure the voltage wiring harness side.





(2)Measure the voltage between ETACS-ECU connector-307 (terminal No. 2) and the body ground.

- The voltage should measure approximately 12 volts (battery positive voltage).

Q. Is the measured voltage approximately 12 volts (battery positive voltage)?

YES Go to Step 10.

NO Go to Step 9.

STEP 9. Check the Wiring harness between ETACS-ECU connector C-307
(terminal No. 2) and fusible link (36).

- Check the power supply line for open circuit and short circuit.

Q. Is the check result normal?

YES The trouble can be an intermittent malfunction How to Cope With Intermittent Malfunctions).
NO Repair the wiring harness between ETACS-ECU connector C-307 and fusible link (36).
STEP 10. Check ETACS-ECU connector C-317 for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q. Is ETACS-ECU connector C-317 in good condition?

YES Go to Step 11.
NO Repair the damaged parts.
STEP 11. Check the Wiring harness between ETACS-ECU connector C-317
(terminal No. 2,9) and center panel unit connector C-124 (terminal No. 15,12).

- Check the input/output lines for open circuit and short circuit.

Q. Is the check result normal?

YES Go to Step 12.
NO Repair the wiring harness between ETACS-ECU connector C-317 and center panel unit connector C-124.
STEP 12. Retest the system.

Q. Does the theft-alarm work normally?

YES The trouble can be an intermittent malfunction How to Cope With Intermittent Malfunctions).
NO Replace the ETACS-ECU.