DTC 15 : Auto-cruise Control Switch System: Diagnosis

Required Special Tool: 

• MB991223: Harness Set

1. STEP 1. Measure the 12-Volt supply circuit voltage at auto-cruise control switch connector C-207. 
   1. Disconnect auto-cruise control switch connector C-207.
   2. Turn the ignition switch to the "ON" position.
      Fig 1: Disconnecting Auto-Cruise Control Switch Connector C-207

      Courtesy of DAIMLERCHRYSLER CORPORATION
   3. Measure the voltage between auto-cruise control switch connector C-207 terminal 1 and ground.
      • The voltage should measure battery positive voltage.
   4. Turn the ignition switch to the "LOCK" (OFF) position, connect auto-cruise control switch connector C-64.

   Q: Is the measured voltage battery positive voltage? 

   YES  : Go to  Step 5.

   NO:  Go to Step 2.

   Fig 2: Measuring Voltage Between Auto-Cruise Control Switch Connector C-207 Terminal 1 And Ground

   Courtesy of DAIMLERCHRYSLER CORPORATION
2. STEP 2. Check auto-cruise control switch connector C-207 and clock spring connectors C-205 and C-214 for loose, corroded or damaged terminals, or terminals pushed back in the connector. 

   Q: Are the connectors and terminals in good condition? 

   YES  : Go to Step 3.

   NO:  Repair or replace the faulty connector. (Refer to , HARNESS CONNECTOR INSPECTION ). Go to  Step 10

   Fig 3: Checking Auto-Cruise Control Switch Connector C-207 And Clock Spring Connectors C-205 And C-214

   Courtesy of DAIMLERCHRYSLER CORPORATION
3. STEP 3. Check the clock spring. 

   Refer to AIR BAG MODULES AND CLOCK SPRING .

   Q: Is the clock spring in good condition? 

   YES  : Go to Step 4.

   NO:  Replace the clock spring. (Refer to AIR BAG MODULES AND CLOCK SPRING ). Go to  Step 10.

4. STEP 4. Check the harness wire between junction block fuse number 21 and auto-cruise control switch connector C-207 terminal 1 for damage. 

   Q: Is the harness wire in good condition? 

   YES  : It can be assumed that this malfunction is intermittent. (Refer to HOW TO COPE WITH INTERMITTENT MALFUNCTIONS ). Go to  Step 10.

   NO:  Repair the damaged harness wire. Go to  Step 10.

   Fig 4: Checking Auto-Cruise Control Switch Connector C-207

   Courtesy of DAIMLERCHRYSLER CORPORATION
5. STEP 5. Measure the signal voltage at auto-cruise control-ECU connector C-21 by backprobing. 
   1. Do not disconnect auto-cruise control-ECU connector C-21.
   2. Turn the ignition switch to the "ON" position.
      Fig 5: Disconnecting Auto-Cruise Control-ECU Connector C-21

      Courtesy of DAIMLERCHRYSLER CORPORATION
   3. Measure the voltage between auto-cruise control-ECU connector C-21 terminal 12 and ground by backprobing.
      • The voltage should measure 6.8 and 7.2 volts. (The MAIN switch is at the "ON" position.)
   4. Measure the voltage between auto-cruise control-ECU connector C-21 terminal 9 and ground by backprobing, when the MAIN switch is at the "ON" position.
      • The voltage should measure 0 volt. (SET, RESUME and CANCEL switches are at the "OFF" position.)
      • The voltage should measure between 0.4 and 2.3 volts. (SET switch is at the "ON" position.)
      • The voltage should measure between 2.3 and 3.5 volts. (RESUME switch is at the "ON" position.)
      • The voltage should measure between 1 volt or less. (CANCEL switch is at the "ON" position.)
   5. Turn the ignition switch to the "LOCK" (OFF) position.
      Fig 6: Measuring Voltage Between Auto-Cruise Control-ECU Connector C-21 Terminal 12 And Ground

      Courtesy of DAIMLERCHRYSLER CORPORATION

   Q: Are all of the measured voltages satisfied? 

   YES  : Check that DTC 15 is not set. If DTC 15 is not set, It can be assumed that this malfunction is intermittent. (Refer to HOW TO COPE WITH INTERMITTENT MALFUNCTIONS ). If DTC 15 is set, replace the auto-cruise control-ECU (Refer to AUTO-CRUISE CONTROL  ), and then Go to  Step 10

   NO:  Go to Step 6.

6. STEP 6. Check auto-cruise control-ECU connector C-21, auto-cruise control switch connector C-207 and clock spring connectors C-205 and C-214 for loose, corroded or damaged terminals, or terminals pushed back in the connector. 

   Q: Are the connectors and terminals in good condition? 

   YES  : Go to Step 7.

   NO:  Repair or replace the faulty connector. (Refer to , HARNESS CONNECTOR INSPECTION ). Go to  Step 10

   Fig 7: Checking Auto-Cruise Control-ECU Connector C-21

   Courtesy of DAIMLERCHRYSLER CORPORATION
   Fig 8: Checking Auto-Cruise Control Switch Connector C-207 And Clock Spring Connectors C-205 And C-214

   Courtesy of DAIMLERCHRYSLER CORPORATION
7. STEP 7. Check the auto-cruise control switch. 
   1. Remove the auto-cruise control switch. (Refer to AUTO-CRUISE CONTROL  .)
   2. Measure the resistance between the terminals when each of the SET, RESUME, CANCEL and MAIN switch is pressed.
      RESISTANCE CHART
      
      

      SWITCH POSITION	RESISTANCE BETWEEN:
      MAIN switch "OFF"	Terminals 1 and 2	Less than 2 ohms
      MAIN switch "ON"	Terminals 1 and 2	Approximately 3.9 kΩ
      CANCEL switch "ON"	Terminals 2 and 3	Approximately 0 Ω
      RESUME switch "ON"	Terminals 2 and 3	Approximately 910 Ω
      SET switch "ON"	Terminals 2 and 3	Approximately 220 Ω

   Q: Does the measured values meet the table above? 

   YES  : Go to Step 8.

   NO:  Replace the auto-cruise control switch. (Refer to AUTO-CRUISE CONTROL  ). Go to  Step 10.

   Fig 9: Auto-Cruise Control Switch Circuit Diagram

   Courtesy of DAIMLERCHRYSLER CORPORATION
8. STEP 8. Check the clock spring. 

   Refer to AIR BAG MODULES AND CLOCK SPRING .

   Q: Is the clock spring in good condition? 

   YES  : Go to Step 9.

   NO:  Replace the clock spring. (Refer to AIR BAG MODULES AND CLOCK SPRING ). Go to  Step 10.

9. STEP 9. Check the harness wire between auto-cruise control-ECU connector C-21 terminals 9, 12 and auto-cruise control switch connector C-207 terminals 2, 3 for damage. 

   Q: Is the harness wire in good condition? 

   YES  : It can be assumed that this malfunction is intermittent. (Refer to HOW TO COPE WITH INTERMITTENT MALFUNCTIONS ). Go to Step 10.

   NO:  Repair the damaged harness wire. Go to Step 10.

   Fig 10: Checking Harness Wire Between Auto-Cruise Control-ECU Connector C-21

   Courtesy of DAIMLERCHRYSLER CORPORATION
   Fig 11: Checking Auto-Cruise Control Switch Connector C-207

   Courtesy of DAIMLERCHRYSLER CORPORATION
10. STEP 10. Check the diagnostic trouble codes. 

    Q: Is DTC 15 set? 

    YES  : Go to  Step 1.

    NO:  This procedure is complete.