Trouble Shooting: Pre-Check

WARNING: This page is about a different car, the 2003 Toyota 4Runner. However, it is still accessible from the selected car via links, so may be relevant.

NOTE: Use the Customer Problem Analysis (Cruise Control System Check List) in conjunction with the trouble shooting flow chart. See Fig 1 and Fig 2 .

Diagnose System :
1. Description:
  ECM controls the function of the cruise control on a vehicle.
  
  Data on the cruise control and on the DTC can be read from the DLC3 on the vehicle. If CRUISE MAIN indicator light does not comes 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. See Fig 3 and Fig 4 .
  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.
3. Check the indicator:
  1. Turn the ignition switch to ON.
  2. 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.
4. Check the DTC. See Fig 5.
5. Output of DTC using diagnosis check wire:
  1. Turn the ignition switch to ON.
  2. Using SST, connect terminals TC and CG of DLC3. See Fig 6.
    SST 09843-18040.
  3. Read the DTC on the CRUISE MAIN indicator light.
Using Hand-Held Tester :
1. Hook up the hand-held tester to the DLC3.
2. Monitor the ECU data by, following the prompts on the tester screen.

NOTE: According to 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 a first step of troubleshooting is one of the method to shorten the labor time.

Data List :
- Connect the hand-held tester to the DLC3.
- Turn the ignition switch to ON.
- According to the display on tester, read the "DATA LIST". See Fig 7.
DTC Clear :
1. The following actions will erase the DTCs and freeze frame data.
  - Hand-Held Tester: Operating the hand-held tester to erase the codes.
  
  - Except Hand-Held Tester: Disconnecting the battery terminals or EFI fuse.
2. After completing repairs, the DTC retained in 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.
Problem Symptom Confirmation (Road Test) :
1. Inspect the SET switch.
  1. Push the main switch button to ON. See Figure.
  2. Drive at a desired speed (40 km/h (25 mph) or higher).
  3. Push down the control switch to the "-/SET". See Figure.
  4. After releasing the switch, check that the vehicle cruises at the desired speed.
2. Inspect The "+" Switch :
  1. Push the main switch button to ON. See Figure.
  2. Drive at a desired speed (40 km/h (25 mph) or higher).
  3. Check that the vehicle speed increases while the control switch is pull up to +/RES, and that the vehicle cruises at the set speed when the switch is released. See Figure.
  4. Momentarily push the control switch upward to the +/RES, and then immediately release it. Check that the vehicle speed increases by about 1.5 km/h (Tap-up function).
3. Inspect The " - " Switch
  1. Push the main switch button to ON. See Figure.
  2. Drive at a desired speed (40 km/h (25 mph) or higher).
  3. Check that the vehicle speed decreases while the control switch is push down to "-/SET", and the vehicle cruises at the set speed when the switch is released. See Figure.
  4. Momentarily push the control switch downward to " /SET", and then immediately release it. Check that the vehicle speed decreases by about 1.5 km/h (Tap-down function).
4. Inspect The CANCEL Switch :
  1. Push the main switch button to ON. See Figure.
  2. Drive at a desired speed (40 km/h (25 mph) or higher).
  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 control switch to CANCEL. See Figure.
5. Inspect The RES Switch :
  1. Push the main switch button to ON. See Figure.
  2. Drive at a desired speed (40 km/h (25 mph) or higher).
  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.
    
    - Pull the control switch to CANCEL.
  4. After the control switch is pull up to +/RES at the driving speed of more than 40 km/h (25 mph), check that the vehicle restores the speed before the cancellation. See Figure.

Problem Symptoms Table

Symptom

Suspect Area

See

Main switch cannot be turned ON. (Cruise indicator light in combination meter is not lit.)

.....

Cruise control switch circuit

⁽¹⁾

.....

CRUISE MAIN indicator light circuit

⁽²⁾

.....

ECM

⁽³⁾

Vehicle speed setting cannot be done. (Although indicator light in combination meter is lit when the main switch is turned ON, they go off when vehicle speed is set).

.....

Cruise control switch circuit

⁽¹⁾

.....

ECM

⁽³⁾

Setting cannot be done. (Indicator light in combination meter is lit when the main switch is turned ON and they remain ON while setting).

.....

Cruise control switch circuit

⁽¹⁾

.....

Stop Light Switch Circuit

⁽⁴⁾

.....

PNP Switch Circuit

⁽⁵⁾

.....

Combination Meter System

⁽⁶⁾

.....

ECM

⁽³⁾

While the vehicle is driving with cruise control, the set control is canceled: (Indicator light and CRUISE remain ON).

.....

Cruise control switch circuit

⁽¹⁾

.....

Vehicle Speed Sensor Circuit

⁽⁷⁾

.....

Stop Light Switch Circuit

⁽⁴⁾

.....

CRUISE MAIN indicator light circuit

⁽²⁾

.....

PNP Switch Circuit

⁽⁵⁾

.....

ECM

⁽³⁾

Hunting (Speed is not Constant)

.....

Vehicle Speed Sensor Circuit

⁽⁷⁾

.....

ECM

⁽³⁾

Setting cannot be cancelled. (When Coast, Acceleration, Resume, Set speed change and Control switch are operated).

.....

Cruise control switch circuit

⁽¹⁾

.....

ECM

⁽³⁾

DTC is not output, or is output when should not be.

.....

Diagnosis Circuit

⁽⁸⁾

.....

ECM

⁽³⁾

CRUISE MAIN indicator light does not light up.

.....

Cruise control switch circuit

⁽¹⁾

.....

CRUISE MAIN indicator light circuit

⁽²⁾

.....

ECM

⁽³⁾

⁽¹⁾	CRUISE CONTROL SWITCH CIRCUIT

⁽²⁾	CRUISE MAIN INDICATOR LIGHT

⁽³⁾	See, HOW TO TROUBLESHOOT ECU CONTROLLED SYSTEMS under INTRODUCTION

⁽⁴⁾	DTC P0571/52: BRAKE SWITCH "A" CIRCUIT

⁽⁵⁾	See DTC P0705 TRANSMISSION RANGE SENSOR CIRCUIT MALFUNCTION (PRNDL INPUT) under DIAGNOSTICS.

⁽⁶⁾	See Combination meter problem symptoms table under instrument panel/meter.

⁽⁷⁾	DTC P0500/21,23: VEHICLE SPEED SENSOR "A"

⁽⁸⁾	DIAGNOSIS CIRCUIT

Fig 1: Customer Problem Analysis (Cruise Control System Check List)

Fig 2: Trouble Shooting Flow Chart

Fig 3: Identifying DLC3

Fig 4: Identifying DLC3 Terminal Specifications

Fig 5: Checking Indicator light DTC

Fig 6: Identifying DLC3 Terminals Tc & CG

Fig 7: Data List

Fig 8: Diagnostic Trouble Code Chart

Fig 9: Input Signal Chart