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Cruise Control System - Diagnosis: Pre-Check

  1. DIAGNOSIS SYSTEM 
    1. Description

      The ECM stores trouble codes. The diagnosis system allows for reading of the trouble codes from the DLC3. If the CRUISE MAIN indicator does not come on after DTC check, it means a malfunction has occurred in the cruise control system.

      Use the hand-held tester or SST to check and solve the problem.

    2. Check the DLC3.

      The ECM uses ISO 9141-2 for communication. The terminal arrangement of the DLC3 complies with SAE J1962 and matches the ISO 9141-2 format.

      Fig 1: Identifying DLC3 Terminals
      G01450675Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      Fig 2: DLC3 Terminals Reference Table
      G01450676Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      HINT:

      If the display shows "UNABLE TO CONNECT TO VEHICLE" after connecting the hand-held tester to the DLC3 and turning the ignition switch to the ON position, there is a problem either with the vehicle or the tool. (Hand-held tester ONLY)

      • If communication is normal when connecting the tool to another vehicle, inspect DLC3 on the original vehicle.
      • If communication is still not possible when connecting the tool to another vehicle, it suggests the problem is the tool's own. In this case, consult the Service Department listed in the tool's instruction manual.
    3. Check the indicator.
      1. Turn the ignition switch to the ON position.
      2. Check that the CRUISE MAIN indicator light comes on when the cruise control main switch ON-OFF button is pushed on, and that the indicator light goes off when the ON-OFF button is pushed off.
        Fig 3: Identifying Cruise Control Main Switch
        G01450677Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      HINT:

      If there is a problem with the indicator, inspect the cruise main indicator light circuit (See CRUISE MAIN INDICATOR LIGHT CIRCUIT ).

      Fig 4: Identifying Cruise Main Indicator Light & Location
      G01450678Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      HINT:

      If malfunction occurs in the vehicle speed sensors, stop lamp switch or other related parts while cruise control driving, the ECM actuates AUTO CANCEL of the cruise control. Then CRUISE MAIN indicator light starts to blink informing the driver of the malfunction. At the same time, data of the malfunction is stored in ECM as Diagnostic Trouble Code (DTC).

      Fig 5: Identifying Indicator Light Blinking Pattern
      G01450679Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  2. DTC CHECK USING SST CHECK WIRE 
    1. Check DTCs using SST check wire.
      1. Turn the ignition switch off.
      2. Using SST, short-circuit between terminals TC and CG of the DLC3.

        SST 09843-18040

      3. Turn the ignition switch to the ON position.
        Fig 6: Identifying DLC3 Terminals
        G01450680Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      4. Read and record DTCs from the CRUISE MAIN indicator light on the combination meter. As examples, refer to the Fig 7 for the blinking of the normal code and trouble code 52.
        Fig 7: Identifying Blinking Patterns
        G01450682Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

        HINT:

        If the CRUISE MAIN indicator light does not blink because of any DTC or in the normal code blinking pattern, inspect the following circuits.

        RELEVENT CIRCUIT INSPECTION TABLE

        Relevent Circuit Go To
        TC & CG Terminal Circuit DLC3 CIRCUIT 
        CRUISE MAIN Indicator Light Circuit CRUISE MAIN INDICATOR LIGHT CIRCUIT 
    2. Clear the DTCs.
      1. Turn the ignition switch off.
      2. If DTCs are indicated, repair the relevant circuits referring to the (See DIAGNOSTIC TROUBLE CODE TABLE ).
      3. Clear the DTCs according to either one of the following procedures.
        • Disconnect the negative (-) battery cable for at least 10 seconds, then reconnect it.
        • Remove the EFI fuse for at least 10 seconds, then reinstall it.
    3. Recheck DTCs again (see procedure ( a)).
  3. DTC CHECK USING HAND-HELD TESTER 
    1. Check DTCs using the hand-held tester.
      1. Turn the ignition switch off.
      2. Connect the hand-held tester to the DLC3.
      3. Turn the ignition switch to the ON position.
      4. Read DTCs on the tester screen.
        Fig 8: Connecting Hand-Held Tester To DLC3
        G01450683Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Clear the DTCs using the hand-held tester.
      1. Turn the ignition switch off.
      2. Turn the ignition switch to the ON position.
      3. Clear the DTCs following the prompts on the tester screen.

      HINT:

      Hand-held tester has a "Snapshot" function which records the monitored data. Refer to the hand-held tester operator's manual for further details.

  4. DATA LIST 

    CRUISE CONTROL (ECM): 

    HINT:

    Following the DATA LIST displayed by the hand-held tester, you can read the values of the switches, sensors, actuators and so on without parts removal. Reading the DATA LIST as the first step of troubleshooting is one of the methods to shorten labor time.

    1. Connect the hand-held tester to the DLC3.
    2. Turn the ignition switch to the ON position.
    3. According to the display on the tester, read the "DATA LIST".
      Fig 9: Cruise Control (ECM) - Data List Table
      G01450684Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  5. ACTIVE TEST 

    COMBINATION METER: 

    HINT:

    Performing the ACTIVE TEST using the hand-held tester allows the relay, VSC, the actuator and so on to operate without parts removal. Performing the ACTIVE TEST as a first step of troubleshooting is one of the method to shorten labor time.

    It is possible to display the DATA LIST during the ACTIVE TEST.

    1. Connect the hand-held tester to the DLC3.
    2. Turn the ignition switch to the ON position.
    3. According to the display on tester, perform the " 5 (ACTIVE TEST)".
      Fig 10: Combination Meter - Active Test Table
      G01450685Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  6. PROBLEM SYMPTOM CONFIRMATION (ROAD TEST) 
    1. Inspect the "SET" function.
      1. Push the ON-OFF button on.
      2. Drive at a desired speed of 40 km/h (25 mph) or higher.
      3. Push down the control switch lever to "SET/COAST".
      4. After releasing the lever, check that the vehicle cruises at the set speed.
        Fig 11: Inspecting Set Function
        G01450686Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Inspect the "ACC" function.
      1. Set a desired speed as in procedure ( a).
      2. Check that vehicle speed increases while the control switch lever is pushed up to "RES/ACC".
      3. Check that the vehicle cruises at the newly set speed when the switch lever is released.
      4. Momentarily (approximately 0.6 second) push up the control switch lever to "RES/ACC" and then release it. Check that vehicle speed increases approximately 1.6 km/h (1 mph) with each lever operation (Tap-up function).
        Fig 12: Inspecting ACC Function
        G01450687Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    3. Inspect the "COAST" function.
      1. Set a desired speed as in procedure ( a).
      2. Check that vehicle speed decreases while the control switch lever is pushed down to "SET/COAST".
      3. Check that the vehicle cruises at the newly set speed when the switch lever is released.
      4. Momentarily (approximately 0.6 second) push down the control switch to "SET/COAST", and then release it. Check that vehicle speed decreases approximately 1.6 km/h (1 mph) with each lever operation (Tap-down function).
        Fig 13: Inspecting COAST Function
        G01450688Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

        HINT:

        Cruise control system automatically cancels when the vehicle speed goes below 40 km/h (25 mph).

    4. Inspect the "CANCEL" function.
      1. Set a desired speed as in procedure ( a).
      2. Check that the system cancels cruise control when doing one of the following:
        • Depressing the brake pedal
        • Shifting into any position except D and 4 while driving
        • Pushing the ON-OFF button off
        • Pulling the cruise control switch lever to "CANCEL"
          Fig 14: Inspecting CANCEL Function
          G01450689Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    5. Inspect the "RES" function.
      1. Set a desired speed as in procedure ( a).
        • After cancelling the cruise control according to any of the above operations (other than pushing the main switch ON-OFF button off), push up the switch lever to "RES/ACC" at a speed of 40 km/h (25 mph) or higher.
        • Check that the vehicle resumes the previously set speed.
          Fig 15: Inspecting RES Function
          G01450690Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

          HINT:

          "RES" function does not resume the set speed when vehicle speed goes below 40 km/h (25 mph).

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