Inspection Procedure 1

INSPECTION PROCEDURE 1: The Ignition Key cannot be Registered

TECHNICAL DESCRIPTION (COMMENT)
The ignition key transponder or the ETACS-ECU is suspected to be defective

TROUBLESHOOTING HINTS

- Malfunction of the ignition key
- Malfunction of ETACS-ECU

Required Special Tools:
- MB991958: Scan Tool (MUT-III Sub Assembly)
- MB991824: VCI
- MB991827: MUT-III USB Cable
- MB991910: MUT-III Main Harness A

STEP 1. Check the diagnostic trouble code

Use scan tool MB991958 to check if DTC B1702 or B1703 is set

CAUTION: To prevent damage to scan tool MB991958, always turn the ignition switch to "LOCK" (OFF) position before connecting or disconnecting scan tool




1. Connect scan tool MB991958 to the data link connector
2. Turn the ignition switch "ON" position
3. Read the immobilizer system diagnostic trouble code
4. Turn the ignition switch to the "LOCK" (OFF) position

Q: Does DTC B1702 or B1703 resets?

DTC B1702 is set : Refer to DTC B1702

DTC B1703 is set : Refer to DTC B1703

No DTC is set : Replace the ignition key and then register the ID codes again Then go to Step 2

STEP 2. Retest the system

Q: Does registered ignition key function properly?

YES: The procedure is complete

NO: Replace the ETACS-ECU and register the ID codes again Retest the system