Cruise Control System: Pre-Check
- DIAGNOSIS SYSTEM
- Description
ECM controls of the cruise control the function on a vehicle.
Data stored in the cruise control memory and on the DTC can be read from the DLC3 on the vehicle. If CRUISE MAIN indicator light does not come on after the DTC check, there is a malfunction of the cruise control.
Use the hand-held tester or SST to check and solve the problem.
- Check the DLC3.
The vehicle's ECM uses ISO 9141-2 for communication. The terminal arrangement of DLC3 complies with SAE J1962 and matches the ISO 9141-2 format.
HINT:
If the display shows "UNABLE TO CONNECT TO VEHICLE" after connecting the hand-held tester to the DLC3 and turning the ignition ON, there is a problem either with the vehicle or with the tool.
- If communication is normal when connecting the tool to another vehicle, inspect the DLC3 on the original vehicle.
- If communication is still not possible when connecting the tool to another vehicle, the problem is probably in the tool itself. Consult the Service Department listed in the tool's instruction manual.
- Check the indicator.
- Turn the ignition switch ON.
- Check that the CRUISE MAIN indicator light comes on when the main switch button is turned ON, and that the indicator light goes off when the main switch is turned OFF.
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
HINT:
If there is a problem with the indicator, (See CRUISE MAIN INDICATOR LIGHT CIRCUIT ).
- Check the DTC.
HINT:
If a malfunction occurs in the vehicle speed sensors or stop lamp switch assy, etc. during cruise control driving, the ECM actuates AUTO CANCEL of the cruise control and then the CRUISE MAIN indicator light will start to blink, informing the driver of a malfunction. At the same time, data of the malfunction is stored as a diagnostic trouble code, or DTC.
- Output of DTC using diagnosis check wire.
- Using SST, connect terminals TC and CG of DLC3.
SST 09843-18040
- Turn the ignition switch ON.
- Read the DTC on the CRUISE MAIN indicator light.
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
HINT:
If the DTC is not output, (See CRUISE MAIN INDICATOR LIGHT CIRCUIT ) and (See DIAGNOSIS CIRCUIT ).
As an example, the normal blinking pattern and the blinking pattern for code 52 are shown in Fig 6.
- Using SST, connect terminals TC and CG of DLC3.
- Description
- USING HAND-HELD TESTER
- Connect the hand-held tester to DLC3.
- Monitor the ECU data by 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.
- DATA LIST
HINT:
From the DATA LIST displayed on the hand-held tester, you can read the value of the switch, the sensor and so on without removing parts. Reading the DATA LIST as the first step to troubleshooting is one way to shorten labor time.
- Connect the hand-held tester to DLC3.
- Turn the ignition switch ON.
- According to the display on the tester, read the "DATA LIST".
HINT:
"3" is OK but "1" is NG --> ECM failure
"1" is OK but "2" is NG --> DTC output or ECM failure
"3" is OK but cruise indicator does not turn ON --> CRUISE MAIN indicator or wire harness or ECM failure
- DTC CLEAR
- The following methods will erase the DTCs and freeze frame data.
- The hand-held tester can be used to erase the codes.
- Disconnecting the battery terminals or EFI No. 1 fuse can also erase the codes.
- After completing repairs, the DTC retained in the memory can be cleared by removing the EFI No. 1 fuse for 1 minute or more with the ignition switch OFF.
- Check that the normal code is displayed after connecting the fuse.
- The following methods will erase the DTCs and freeze frame data.
- PROBLEM SYMPTOM CONFIRMATION (ROAD TEST)
- Inspect the SET switch.
- Push the main switch button ON.
- Drive at a desired speed (40 km/h (25 mph) or higher).
- Push down the control switch to the -/SET position.
- After releasing the switch, check that the vehicle cruises at the desired speed.
- Inspect the '+' switch.
- Push the main switch button ON.
- Drive at a desired speed (40 km/h (25 mph) or higher).
- Check that the vehicle speed increases when the control switch is pushed up to +/RES, and that the vehicle cruises at the set speed when the switch is released.
- Push the control switch to +/RES, and then immediately release it. Check that the vehicle speed increases by about 1.6 km/h (Tap-up function).
- Inspect the '-' switch.
- Push the main switch button ON.
- Drive at a desired speed (40 km/h (25 mph) or higher).
- Check that the vehicle speed decreases while the control switch is pushed down to -/SET, and the vehicle cruises at the set speed when the switch is released.
- Push the control switch to -/SET, and then immediately release it. Check that the vehicle speed decreases by about 1.6 km/h (Tap-down function).
- Inspect the CANCEL switch.
- Push the main switch button ON.
- Drive at a desired speed (40 km/h (25 mph) or higher).
- After doing one of the following, check that the cruise control system is cancelled and that the normal driving mode is reset.
- Depressing the brake pedal.
- Shift to any gear besides D.
- Pushing the main switch button OFF.
- Pulling the control switch CANCEL.
- Inspect the RES switch.
- Push the main switch button ON.
- Drive at a desired speed (40 km/h (25 mph) or higher).
- After doing one of the following, check that the cruise control system is cancelled and that the normal driving mode is reset.
- Depressing the brake pedal.
- Shift to any gear besides D.
- Pulling the control switch CANCEL.
- After the control switch is pulled up to +/RES at the driving speed of more than 40 km/h (25 mph), check that the vehicle resumes the same speed maintained before the cancellation.
- Inspect the SET switch.