Inspection Procedure E-3: Keyless Entry System: Encrypted Code Cannot Be Registered: Diagnosis

Required Special Tools: 

• MB991223: Test Harness Set
• MB991958: Scan Tool (MUT-III Sub Assembly)
  • MB991824: Vehicles communication interface
  • MB991827: MUT-III USB cable
  • MB991911: MUT-III Main harness B

1. STEP 1. Check trouble symptom. 

   Q: Can the encrypted code register mode be set? 

   1. YES:  Go to Step  3.
   2. NO  : Go to Step 2.
2. STEP 2. Check the input signal (by using the Pulse check mode of the monitor). 

   Check the input signals from the following switches:

   • Key reminder switch
   • Hazard warning light switch
   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 SWS MONITOR ."
   2. Operate scan tool MB991958 according to the procedure below to display "Pulse check."
      1. Select "Interactive Diagnosis."
      2. Select "System select."
      3. Select "SWS."
      4. Select "Pulse Checking."
   3. Check the scan tool MB991958 sounds or not.
   4. If the switches (see table below), which are applicable for the input signal check, are operated.
   ITEM CHECK CONDITIONS
   
   

   ITEM NAME	CHECK CONDITIONS
   Key reminder switch	Remove and reinsert the ignition key
   Hazard warning light switch	Turn the hazard warning light switch from the "OFF" to "ON" position.

   Q: When the key reminder switch and the hazard warning light switch are operated, does scan tool MB991958 sound in each case? 

   Buzzer of scan tool MB991958 sounds normally: 

   Replace the ETACS-ECU. Check that the encrypted code can be registered in the transmitter.

   Scan tool MB991958 does not sound when the ignition key is removed and reinserted  : Refer to INSPECTION PROCEDURE P-1: ETACS-ECU DOES NOT RECEIVE A SIGNAL FROM THE KEY REMINDER SWITCH .

   Scan tool MB991958 does not sound when the hazard warning light switch is turned from "OFF" to "ON"  : Refer to INSPECTION PROCEDURE P-2: THE ETACS-ECU DOES NOT RECEIVE A SIGNAL FROM THE HAZARD WARNING LIGHT SWITCH .

   Fig 1: Connecting Scan Tool To Data Link Connector

   Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
3. STEP 3. Check the transmitter. 

   Q: When the transmitter's battery is replaced, can the encrypted code be registered? 

   1. YES:  No action to be taken.
   2. NO  : Replace the transmitter. If the encrypted code can not be registered by means of the new transmitter, replace the ETACS-ECU. Check that the encrypted code can be registered in the transmitter.