Diagnosis System

When troubleshooting a vehicle with a diagnosis system, the only difference from the usual troubleshooting procedure is connecting the Techstream to the vehicle and reading various data output from the vehicle's skid control ECU.

The skid control ECU records DTCs when the computer detects a malfunction in the ECU itself or in its circuits. To check the DTCs, connect the Techstream to the DLC3 on the vehicle. The Techstream can clear the DTCs, activate the various actuators, and check the Freeze Frame Data and Data List.

1. Check the battery voltage.

   Standard Voltage: 

   11 to 14 V 

   If the voltage is below 11V, recharge the battery before proceeding to the next step.

2. Check the DLC3 (See HOW TO TROUBLESHOOT ECU CONTROLLED SYSTEMS ).

1. If the skid control ECU detects a malfunction, the ABS warning, brake warning, slip indicator, and master warning (for vehicle with the master warning light) lights will come on in order to warn the driver.
2. The DTCs are simultaneously stored in the memory.

   The DTCs can be read by connecting SST between terminals TC and CG of the DLC3 and observing the blinking pattern of the ABS warning and slip indicator lights, or by connecting the Techstream (See DTC CHECK / CLEAR  ).

3. This system has a Test Mode (signal check) function.

   The DTCs can be read by connecting SST between terminals TS and CG of the DLC3 and observing the blinking pattern of the ABS warning and slip indicator lights, or by connecting the Techstream (See TEST MODE PROCEDURE  ).

1. Release the parking brake.
   NOTE: Before releasing the parking brake, move the shift lever to P for safety.

   HINT:

   When the parking brake is applied or the brake fluid level is low, the brake warning light comes on.

   Fig 1: Identifying ABS Warning, Brake Warning, Slip Indicator, And Master Warning Lights Indicator

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. When the ignition switch is turned to ON, check that the ABS warning, brake warning, TRAC OFF indicator, VSC OFF indicator and slip indicator lights all come on for approximately 3 seconds.

   HINT:

   • If the warning light and indicator light check result is not normal, proceed to troubleshooting for the ABS warning, brake warning, TRAC OFF indicator, VSC OFF indicator and slip indicator light circuits.
   • If the indicator remains on or does not come on, proceed to troubleshooting for the light circuits listed below.
     TROUBLESHOOTING CHART
     
     

     Trouble Area	See Procedure
     ABS warning light circuit (Remains on)	ABS WARNING LIGHT REMAINS ON
     ABS warning light circuit (Does not come on)	ABS WARNING LIGHT DOES NOT COME ON
     Brake warning light circuit (Remains on)	BRAKE WARNING LIGHT REMAINS ON
     Brake warning light circuit (Does not come on)	BRAKE WARNING LIGHT DOES NOT COME ON
     TRAC OFF indicator light circuit (Remains on)	TRAC OFF INDICATOR LIGHT REMAINS ON
     TRAC OFF indicator light circuit (Does not come on)	TRAC OFF INDICATOR LIGHT DOES NOT COME ON
     VSC OFF indicator light circuit (Remains on)	VSC OFF INDICATOR LIGHT REMAINS ON
     VSC OFF indicator light circuit (Does not come on)	VSC OFF INDICATOR LIGHT DOES NOT COME ON
     Slip indicator light circuit (Remains on)	SLIP INDICATOR LIGHT REMAINS ON
     Slip indicator light circuit (Does not come on)	SLIP INDICATOR LIGHT DOES NOT COME ON

     Fig 2: Identifying ABS Warning, Brake Warning, TRAC OFF Indicator, VSC OFF Indicator And Slip Indicator Lights

     Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002