Keyless Start System - Intermittent No Start, Possible DTC C426

Intermittent no start with all smart keys, ICM won't turn on

Topic number LI80.57-P-053608

Version 4

Design group 80.57 Drive authorization systems (DAS)

Date 08-30-2012

Validity All W/X164 and 251 vehicles

Reason for change Further clarification of EZS fault events added

Complaint
Intermittent no start with both smart keys and the ICM will not turn on (only the multi function display will illuminate typical of a CAN wake-up). No codes are stored in the EIS ECU. The central locking system operates normally. The guided test for the EIS and smart keys as outlined in DAS may not reveal a fault.

Please Note:
^ If the fault cannot be verified, then monitor if there is a delay to when the ICM turns on 'after' the ignition is turned to the number 2 position.

Normally the reaction time of the ICM should be immediate.

^ Monitor if the complaint can be readily duplicated immediately after the vehicle is unlocked.

^ In the initial short test, there are no Drive Authorization codes stored in the ME control module.

^ Check the EIS ECU log and verify that there is a fault event stored as shown in the attached file (Initial EIS control unit log).

Cause
Faulty EIS

Remedy
^ Open/Close a PTSS case and attach the Initial Short Test, EIS ECU log, additional ECU logs with related drive authorization codes including freeze frame data and the DAS test result for the EIS (see attached file: DAS_EIS_Test_Result).

^ Perform the guided DAS test in EZS and provide the test result page and a second EZS ECU log (attach these to the PTSS case as well).

Note:
Prior to performing the DAS test, you should see event code "65535" in the EZS ECU log. After performing the DAS test, this code will change to another value such as 4, 6, 17, 25 etc. instead of 65535. This new value will be displayed on the test result page and indicates which component is faulty (EZS, ESL; key) or if the system is okay. As per the second bullet point above, please provide both the initial EZS control unit log, and a second log that shows the processed fault event (e.g. 4, 6, 17, etc.)

Examples of processed fault events:

Fault event 4 = Replace EZS

Fault event 6 = Replace EZS

Fault Event 17 = Replace EZS

Fault Event 25 = All is good; do not replace anything

Please Note:
Claims will be debited if the EIS is replaced for any other reason other than the criteria mentioned in this LI document, and/or the DAS data requested is not attached to the PTSS case (see attached document for example of a drive authorization code indicating replacement of EIS).





File Designation








Symptoms