Inspection Procedure 17: The Cruise control switch (ACC distance switch) signal is not received: Diagnosis

Required Special Tools: 

• MB991223: Harness Set
• MB992006: Extra Fine Probe

1. STEP 1. Check the cruise control switch. 

   Refer to CRUISE CONTROL SYSTEM COMPONENT CHECK .

   Q: Is the check result normal? 

   1. YES:  Go to Step 2
   2. NO:  Replace the cruise control switch.
2. STEP 2. Resistance measurement at cruise control switch connector (ground terminal) 
   1. Disconnect the connector, and measure at the wiring harness side.
   2. Measure the resistance between the cruise control switch connector (ground terminal) and ground.

      OK: The resistance should be 2 ohms or less 

   Q: Is the check result normal? 

   1. YES:  Go to  Step 4
   2. NO:  Go to Step 3
3. STEP 3. Check of open circuit in ground line between cruise control switch connector and ground 

   Q: Is the check result normal? 

   1. YES:  Intermittent malfunction is suspected (Refer to HOW TO COPE WITH INTERMITTENT MALFUNCTION ).
   2. NO:  Repair the clock spring, connector(s) or wiring harness.
4. STEP 4. Check of short to ground, and open circuit in DST+ line between cruise control switch connector and ETACS-ECU connector 

   Q: Is the check result normal? 

   1. YES:  Go to Step 5
   2. NO:  Repair the connector(s) or wiring harness.
5. STEP 5. Using scan tool (M.U.T.-III), check data list. 
   CAUTION: To prevent damage to scan tool (M.U.T.-III), always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool (M.U.T.-III).
   1. Connect scan tool (M.U.T.-III). Refer to "HOW TO CONNECT SCAN TOOL (M.U.T.-III) ."
   2. Check the ETACS-ECU service data.
      • When the cruise control switch (ACC distance switch) is pressed.

        Item No.	Item name	Normal condition
        Item 406	ACC distance switch	ON

      • When the cruise control switch (ACC distance switch) is not pressed.

        Item No.	Item name	Normal condition
        Item 406	ACC distance switch	OFF

        OK: Normal condition is displayed. 

   Q: Is the check result normal? 

   1. YES:  The trouble can be an intermittent malfunction (Refer to HOW TO COPE WITH INTERMITTENT MALFUNCTION ).
   2. NO:  Replace the ETACS-ECU.