Cruise Control System - Diagnosis: Pre-Check

1. Description

   ECM controls the function of the cruise control on a vehicle.

   Data on the cruise control and DTC can be read from DLC3 on the vehicle. If the CRUISE MAIN indicator does not come on after the DTC check, there is a malfunction on the cruise control.

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

2. Check the DLC3.

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

   Fig 1: Checking DLC3

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   TERMINAL SPECIFICATION
   
   

   Terminal No.	Connection/Specified Condition	Condition
   4	Chassis Ground <--> Body Ground/ Ω or less	Always
   7	Bus (+) Line/Pulse Generation	During Communication
   16	Battery Positive <--> Body Ground/9 +/- 14 V	Always

   HINT:

   If the display shows "UNABLE TO CONNECT TO VEHICLE" as connecting the hand-held tester to the DLC3 and turn the ignition switch ON, there is a problem either on the vehicle or on the tool.

   • If communication is normal when the tool is connected to another vehicle, inspect DLC3 on the original vehicle.
   • If communication is still not possible when the tool is connected to another vehicle, the problem is probably in the tool itself, so consult the Service Department listed in the tool's instruction manual.
3. Check the indicator.
   1. (1) Turn the ignition switch ON.
   2. (2) Check that the CRUISE MAIN indicator light comes on when the cruise control main switch is turned on, and that the indicator light goes off when the main switch is turned OFF.
   Fig 2: Checking Cruise Main Indicator Light

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   HINT:

   If the indicator check result is not normal, proceed to troubleshooting (See page COMBINATION METER (2003 MY) ) for the combination meter section.

4. Check the DTC.

   HINT:

   If a malfunction occurs in the vehicle speed sensors or the stop light switch, etc. during cruise control driving, ECU actuates AUTO CANCEL of the cruise control and turns on and off the CRUISE MAIN indicator light to inform the driver of a malfunction. At the same time, the malfunction is stored in the memory as a diagnostic trouble code.

   Fig 3: Identifying Blinking Pattern

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
5. Check the output of DTC using diagnosis check wire.
   1. (1) Turn the ignition switch ON.
   2. (2) Using SST, connect terminal Tc and CG of DLC3. SST 09843-18040
   3. (3) Read DTC on the CRUISE MAIN indicator light.
   Fig 4: Connecting Terminal TC And CG Of DLC3

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   HINT:

   If DTC is not output, inspect the cruise main indicator light circuit or the diagnosis circuit (See page CRUISE MAIN INDICATOR LIGHT CIRCUIT  and 05-1660). As an example, the blinking patterns of normal code and 52 are shown in the illustration.

   Fig 5: Identifying Blinking Pattern

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

CRUISE CONTROL (ECM): 

HINT

Following the DATA LIST displayed by the hand-held tester, you can read the value of the switch, sensor, actuator and so on without parts removal. Reading the DATA LIST as a first step of troubleshooting is one of the method to shorten the labor time.

1. Connect the Hand-held tester to the DLC3.
2. Turn the ignition switch ON.
3. According to the display on the tester, read the "DATA LIST".

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 the labor time.

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

1. Connect the Hand-held tester to the DLC3.
2. Turn the ignition switch ON.
3. According to the display on tester, perform the "ACTIVE TEST".

1. Hook up the hand-held tester to the DLC3.
2. Monitor the ECU data by following the prompts on the tester screen.

HINT:

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

1. Following actions will erase DTC and the freeze frame data.
   1. (1) Hand-Held Tester:

      Operating the hand-held tester to erase the codes.

   2. (2) Except Hand-Held Tester:

      Disconnecting the battery terminals or EFI fuse.

2. After completing repairs, DTC retained in the memory can be cleared by removing the EFI fuse for 1 minutes or more with the ignition switch off.
3. Check that the normal code is displayed after connecting the fuse.

1. Inspect the SET switch.
   1. (1) Push the main switch button to ON.
   2. (2) Drive at a desired speed (40 km/h (25 mph) or higher).
   3. (3) Push down the control switch to the SET/COAST.
   4. (4) After releasing the switch, check that the vehicle cruises at the desired speed.
   Fig 6: Inspecting SET Switch

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Inspect the ACCEL switch.
   1. (1) Push the main switch button to ON.
   2. (2) Drive at a desired speed (40 km/h (25 mph) or higher).
   3. (3) Check that the vehicle speed increase while the control switch is pulled up to RES/ACC, and that the vehicle cruises at the set speed when the switch is released.
   4. (4) Momentarily push the control switch upward in the RES/ACC and then immediately release it. Check that the vehicle speed increases by about 1.5 km/h (Tap-up function).
   Fig 7: Inspecting ACCEL Switch

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
3. Inspect the COAST switch.
   1. (1) Push the main switch button to ON.
   2. (2) Drive at a desired speed (40 km/h (25 mph) or higher).
   3. (3) Check that the vehicle speed decrease while the control switch is pushed down to SET/COAST, and the vehicle cruises at the set speed when the switch is released.
      Fig 8: Inspecting COAST Switch

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   4. (4) Momentarily push the control switch downward to SET/COAST, and then immediately release it. Check that the vehicle speed decrease by about 1.5 km/h (Tap-down function).
4. Inspect the CANCEL switch.
   1. (1) Push the main switch button to ON.
   2. (2) Drive at a desired speed (40 km/h (25 mph) or higher).
   3. (3) When operating one of the followings, check that the cruise control system is cancelled and that the normal driving mode is reset.
      • Depress the brake pedal
      • Shift to except D position
      • Push the main switch button to OFF
      • Pull the cruise control switch to CANCEL
   Fig 9: Inspecting CANCEL Switch

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
5. Inspect the RESUME switch.
   1. (1) Push the main switch button to ON.
   2. (2) Drive at desired speed (40 km/h (25 mph) or higher).
   3. (3) When operating one of the followings, check that the cruise control system is cancelled and that the normal driving mode is reset.
      • Depress the brake pedal
      • Shift to except D position
      • Press the main switch button to OFF
   4. (4) After pulling up the control switch to RES/ACC at the driving speed of more than 40 km/h (25 mph), check that the vehicle restores the speed prior to the cancellation.
   Fig 10: Inspecting RESUME Switch

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

1. Connect the hand-held tester to DLC3
2. Check the control switch (MAIN, CANCEL, SET/COAST, RES/ACC).

Fig 11: Checking Control Switch

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002