Inspection Procedure 13

Inspection Procedure 13: Keyless entry system does not work.

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

KOS-ECU System Circuit (Part 1):

KOS-ECU System Circuit (Part 2):

OPERATION
The receiver antenna module receives lock and unlock signals from the keyless operation key, and sends them to KOS-ECU, and further to ETACS-ECU. Also, when ETACS receives signals from the key reminder switch and all the door switches, ETACS-ECU judges them to activate the keyless entry system.

PROBABLE CAUSES
- Malfunction of CAN bus line
- Malfunction of the door switches
- Malfunction of the key reminder switch
- Malfunction of the receiver antenna module
- Malfunction of the keyless operation key
- Damaged wiring harness and connectors
- Malfunction of the KOS-ECU
- Malfunction of ETACS-ECU

DIAGNOSTIC PROCEDURE

Required Special Tools:
- MB991223: Harness Set
- MB992006: Extra Fine Probe
- MB991958: Scan Tool (M.U.T.-III Sub Assembly)
- MB991824: V.C.I.
- MB991827: M.U.T.-III USB Cable
- MB991910: M.U.T.-III Main Harness A

STEP 1. Using scan tool MB991958, read CAN bus the diagnostic trouble code.

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. Refer to "How to connect scan tool (M.U.T.-III)." How To Connect The Scan Tool (M.U.T.-III)
2. Turn the ignition switch to the "ON" position.
3. Check whether the CAN bus lines related DTC is set.
4. Turn the ignition switch to the "LOCK" (OFF) position.

Q: Is the DTC set?

YES : Repair the CAN bus line (Refer to CAN bus diagnostics table).

NO : Go to Step 2.

STEP 2. Using scan tool MB991958, read the diagnostic trouble code.

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. Refer to "How to connect scan tool (M.U.T.-III)." How To Connect The Scan Tool (M.U.T.-III)
2. Turn the ignition switch to the "ON" position.
3. Check whether the KOS-ECU related DTC is set.
4. Turn the ignition switch to the "LOCK" (OFF) position.

Q: Is the DTC set?

YES : Diagnose the KOS-ECU. Diagnostic Trouble Code Descriptions

NO : Go to Step 3.

STEP 3. Key reminder switch check
1. Disconnect the C-315 ETACS-ECU connector.
2. Measure the resistance at the harness-side connector with the ignition key removed from the ignition key cylinder.






3. Check for continuity between the C-315 ETACS-ECU connector terminal No. 13 and the ground.

OK: Continuity exists (2 Ohms or less)

Q: Is the check result normal?

YES : Go to Step 4.

NO : Check the C-211 key reminder switch connector, the C-315 ETACS-ECU connector, the wiring harness between the C-211 key reminder switch connector (terminal No. 3) and the C-315 ETACS-ECU connector (terminal No. 13), and between the C-211 key reminder switch connector (terminal No. 2) and the ground. If they are normal, replace the key reminder switch.

STEP 4. Using scan tool MB991958, check data list.
Check the signals related to the keyless entry system operation.






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. Refer to "How to connect the Scan Tool (M.U.T.-III)." How To Connect The Scan Tool (M.U.T.-III)
2. Turn the ignition switch to the "ON" position.
3. Check the ETACS data list.
- Turn the ignition switch to the LOCK (OFF) position.
- Close the driver's door.
- Close the passenger's door.
- Close the RH-side rear door.
- Close the LH-side rear door.
- Close the liftgate.
- Remove the ignition key from the ignition key cylinder.






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

OK: Normal condition is displayed.

Q: Is the check result normal?

YES (Normal conditions are displayed for all the items.) : Go to Step 5.

NO (Normal condition is not displayed for item No. 254.) : Refer to Chassis Electrical, Inspection Procedure 2: ETACS-ECU does not receive any signal from the ignition switch (IG1).

NO (Normal condition is not displayed for item No. 256.) : Refer to Chassis Electrical, Inspection Procedure 5: ETACS-ECU does not receive any signal from the front door switch (LH).

NO (Normal condition is not displayed for item No. 257.) : Refer to Chassis Electrical, Inspection Procedure 6: ETACS-ECU does not receive any signal from the front door switch (RH).

NO (Normal condition is not displayed for item No. 258.) : Refer to Chassis Electrical, Inspection Procedure 8: ETACS-ECU does not receive any signal from the rear door switch (RH).

NO (Normal condition is not displayed for item No. 259.) : Refer to Chassis Electrical, Inspection Procedure 7: ETACS-ECU does not receive any signal from the rear door switch (LH).

NO (Normal condition is not displayed for item No. 260.) : Refer to Chassis Electrical, Inspection Procedure 9: ETACS-ECU does not receive any signal from the liftgate switch.

NO (Normal condition is not displayed for item No. 264.) : Refer to Chassis Electrical, Inspection Procedure 3: ETACS-ECU does not receive any signal from the key reminder switch.

STEP 5. Check KOS-ECU connector C-102 and receiver antenna module connector C-30 for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q: Are KOS-ECU connector C-102 and receiver antenna module connector C-30 in good condition?

YES : Go to Step 6.

NO : Repair or replace the damaged component(s). Refer to General (Electrical), Harness Connector Inspection. Check that the driver's door unlock sensor works normally.

STEP 6. Check the wiring harness between KOS-ECU connector C-102 (terminal Nos. 7, 9, 10 and 32) and receiver antenna module connector C-30 (terminal Nos. 12, 3, 4 and 8).

Q: Is the wiring harness between KOS-ECU connector C-102 (terminal Nos. 7, 9, 10 and 32) and receiver antenna module connector C-30 (terminal Nos. 12, 3, 4 and 8) in good condition?

YES : Go to Step 7.

NO : The wiring harness may be damaged or the connector(s) may have loose, corroded or damaged terminals, or terminals pushed back in the connector. Repair the wiring harness as necessary. Check that the driver's door unlock sensor works normally.

STEP 7. Check with another registered keyless operation key.
Check that the keyless entry function can be used with another keyless operation key.

Q: Can the keyless entry function be used?

YES : Replace the keyless operation key concerned and register the ID codes.

NO : Go to Step 8.

STEP 8. Check of the troubles
Replace ETACS-ECU. After the replacement, perform the coding, and check that the keyless entry system operates normally.

Q: Is the check result normal?

YES : Intermittent malfunction is suspected (Refer to General (Body and Chassis), How to Use Troubleshooting/Inspection Service Points- How to Cope with Intermittent Malfunction).

NO : Replace KOS-ECU and register the ID codes.