Diagnosis System

DIAGNOSIS

If the skid control ECU detects a malfunction, the ABS, VSC and brake warning lights and the slip, downhill assist control and AUTO LSD indicator lights come on in accordance with the trouble area to warn the driver. The table below indicates which lights come on when there are malfunctions in particular functions.

Fig 1: Identifying Warning Lights Symbols Reference Chart

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

DIAGNOSIS CHART

Item / Trouble Area	ABS	EBD	BA (Brake Assist)	TRAC	VSC	Downhill assist control*1	Hill-start assist control*2	AUTO LSD*3
ABS warning light	◦	◦	◦	-	-	-	-	-
Brake warning light	-	◦	◦*4	-	-	-	-	-
VSC warning light	◦	◦	◦	◦	◦	◦	◦	◦
Slip indicator light	◦	◦	◦	◦	◦	◦	◦	◦
Downhill assist control indicator light*1	• (Downhill assist control switch ON)	• (Downhill assist control switch ON)	• (Downhill assist control switch ON)	• (Downhill assist control switch ON)	• (Downhill assist control switch ON)	• (Downhill assist control switch ON)	• (Downhill assist control switch ON)	• (Downhill assist control switch ON)
AUTO LSD indicator light*3	-	-	-	-	-	-	-	-
◦: Light ON •: Light ON (Blinking) -: Light OFF
HINT: 1: w/ Downhill assist control 2: w/ Hill-start assist control 3: for 2WD w/AUTO LSD 4: w/16-inch disc The DTCs can be read by connecting SST (09843-18040) between the TC and CG terminals of the DLC3 and observing the blinking pattern of the ABS and VSC warning lights, or by using Techstream (see DTC CHECK / CLEAR ). This system has a sensor signal check function (see TEST MODE PROCEDURE ).

CHECK WARNING LIGHT AND INDICATOR LIGHT

Release the parking brake lever.
NOTE: Before releasing the parking brake lever, set chocks to hold the vehicle for safety.

HINT:

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

When the ignition switch is turned ON, check that the ABS, VSC and brake warning lights and the slip, downhill assist control and AUTO LSD indicator lights come on and go off in about 3 seconds.

Fig 2: Identifying Warning Lights Symbols Reference Chart

HINT:

If the warning lights do not illuminate, confirm whether the bulbs have burned out, and also check for CAN communication system DTCs, since the skid control ECU and combination meter are connected by the CAN communication line.

If the warning light remains on, perform relevant troubleshooting procedures. The relevant troubleshooting procedures are in the sections listed in the table below.

SECTION TITLE REFERENCE

Section Title	See procedure
ABS Warning Light Remains ON	ABS WARNING LIGHT REMAINS ON
VSC Warning Light Remains ON	VSC WARNING LIGHT REMAINS ON
Brake Warning Light Remains ON	BRAKE WARNING LIGHT REMAINS ON
Slip Indicator Light Remains ON	SLIP INDICATOR LIGHT REMAINS ON
Downhill assist control Indicator Light Remains ON	DOWNHILL ASSIST CONTROL INDICATOR LIGHT REMAINS ON
AUTO LSD Indicator Light Remains ON	AUTO LSD INDICATOR LIGHT REMAINS ON