Inspection Procedure 5

Inspection Procedure 5: IG knob will not turn (keyless operation is not recognized).

CAUTION:
Before replacing the ECU, ensure that the communication circuit is normal.

















TROUBLESHOOTING HINTS

- Configuration function setting

- Damaged wiring harness and connectors

- Malfunctions of the steering lock push switch

- Malfunction of the keyless operation key

- Malfunction of the receiver antenna module

- Malfunction of KOS-ECU

DIAGNOSIS

Required Special Tools:

- MB992006: Extra fine probe

- MB991223: Harness set

- MB991958: Scan Tool (M.U.T.-III Sub Assembly)
- MB991824: Vehicles 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. Check the power supply circuit and the ground circuit to KOS-ECU.

Refer to Inspection procedure 2 "Abnormality in KOS-ECU power supply and ground circuits" Inspection Procedure 3.

Q. Is the power supply circuit and the ground circuit to KOS-ECU in good condition?

YES Go to Step 2.
NO Repair the power supply circuit and the ground circuit to KOS-ECU.
STEP 2. 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 3.

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

STEP 3. Using scan tool MB991958, read the KOS-ECU diagnostic trouble code.

Check if DTC is set to the KOS-ECU.

Q. Is the DTC set?

YES Troubleshoot the KOS. (Refer to Keyless Operation System (KOS).)
NO Go to Step 4.
STEP 4. Using scan tool MB991958, Check the configuration function.

Use the ETACS-ECU configuration function to check that the "F.A.S.T. feature" is set to
"Both enable" or "ENG strt enable".

Q. Is it set to "Both enable" or "ENG strt enable"?

YES Go to Step 5.
NO Use the ETACS-ECU configuration function to set the "F.A.S.T. feature" to "Both enable" or "ENG strt enable". (Refer to ID registration procedure manual - ID codes registration judgement table).
STEP 5. Check the ignition push switch. Measure the resistance at KOS-ECU connector C-31.

(1)Disconnect the KOS-ECU connector C-31.

(2)With the IG knob push switch pressed, measure the resistance at the harness-side connector.





(3)Resistance between the KOS-ECU connector C-31 terminal No. 8 and 34.
OK: The resistance should be 2 ohms or less.

Q. Is the measured resistance 2 ohms or less?

YES Go to Step 6.

NO Check the KOS-ECU C-31 connector, the key reminder switch connector C-213, the ETACS-ECU connector C-317, and the wiring harness between the KOS-ECU connector C-31 (terminal No. 8, 34) and the C-213 key reminder switch connector (terminal No. 10, 4), and repair them if necessary. If they are normal, replace the key reminder switch.

STEP 6. Check the key reminder switch. Measure the resistance at ETACS-ECU connector C-315.

(1)Disconnect the ETACS-ECU connector C-315.

(2)Measure the resistance at the harness-side connector with the ignition key removed from the ignition key cylinder.





(3)Resistance between the ETACS-ECU connector C-315 terminal No. 13 and the ground.
OK: The resistance should be 2 ohms or less.

Q. Is the measured resistance 2 ohms or less?

YES Go to Step 7.

NO Check the key reminder switch connector C-213, the ETACS-ECU connector C-315, the wiring harness between the key reminder switch connector C-213 (terminal No. 3) and the ETACS-ECU connector C-315 (terminal No. 13), and between the key reminder switch connector C-213
(terminal No. 2) and the ground. If they are normal, replace the key reminder switch.

STEP 7. Check with another registered keyless operation key.

Q. Does the IG knob turn? (Is the keyless operation key recognized?)

YES Replace the keyless operation key with which the IG knob does not turn (no recognition) and register the ID codes (Refer to ID registration procedure manual - ID codes registration judgement table).
NO Go to Step 8.
STEP 8. Check KOS-ECU connector C-31 and receiver antenna module connector C-10 for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q. Is KOS-ECU connector C-31 and receiver antenna module connector C-10 in good condition?

YES Go to Step 9.
NO Repair the defective connector.
STEP 9. Check the wiring harness between KOS-ECU connector C-31 (terminal No. 11, 12, 32) and receiver antenna module connector C-10 (terminal No. 2, 1, 8).

- Check the signal wires for open circuit and short circuit.

Q. Is the wiring harness between KOS-ECU connector C-31 (terminal No. 11, 12, 32) and receiver antenna module connector C-10 (terminal No. 2, 1, 8) in good condition?

YES Go to Step 10.
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. Verify that the high-beam headlights illuminate normally.
STEP 10. Check the power supply circuit to the receiver antenna module.
Measure the voltage at receiver antenna module connector C-10.

(1)Disconnect receiver antenna module connector C-10 and measure the voltage available at the harness side of the connector.





(2)Measure the voltage between terminal No. 3 and ground.

- The voltage should measure 5 V.

Q. Is the measured voltage 5 V?

YES Go to Step 11.

NO Replace KOS-ECU and register the ID codes (Refer to ID registration procedure manual - ID codes registration judgement table).

STEP 11. Using the oscilloscope, check the waveform at receiver antenna module connector C-10 and ground by backprobing.

(1)Do not disconnect the receiver antenna module connector C-10.

(2)Connect an oscilloscope to receiver antenna module connector C-10 terminal No.
3 and ground by backprobing.





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

- Check the waveform.

Q. Is the waveform normal?

YES Go to Step 12.

NO Replace the receiver antenna module.

STEP 12. Check of the troubles.

Check that the IG turns (keyless operation is recognized).

Q. Does the IG knob will not turn (keyless operation is not recognized) in good condition?

YES The procedure is complete.
NO Replace KOS-ECU and register the ID codes (Refer to ID registration procedure manual - ID codes registration judgement table).