The downhill assist control system helps to prevent excessive speed on steep downhill descents.
■ System operation
The system will operate when the vehicle is traveling under 15 mph (25 km/h) and the front-wheel drive control switch is in the L4 position.

Press the DAC switch. The indicator will come on, and the system will operate.
With the vehicle traveling at a speed of 15 mph (25 km/h) or less, release your foot from the accelerator or brake pedal to activate the system.
When the system is in operation, the slip indicator will flash, and the stop lights/high mounted stop light will come on. A sound may also occur during the operation. This does not indicate a malfunction.
■ Turning off the system
Press the DAC switch while the system is in operation. The indicator will flash as the system gradually ceases operation, and will turn off when the system is fully off.
Pressing the DAC switch while the indicator is flashing will start the system again.
■Operating tips
The system will operate when the shift lever is in a position other than P.
However, to make effective use of the system it is recommended that the shift lever be shifted to 2 or L.
■The system will not operate when
●The front-wheel drive control switch is in the H2 or H4 position.
●The rear differential is locked.
■The downhill assist control system indicator light flashes when
●The shift lever is in the N position.
●The front-wheel drive control switch is in the H2 or H4 position.
●The rear differential is locked.
■If the brake system overheats
The system will cease operation and a buzzer will sound to alert the driver.
Stop the vehicle in a safe place. (There is no problem with continuing normal driving.)
■System malfunction
●The downhill assist control system indicator does not come on when the engine switch is turned to the ON position.
●The downhill assist control system indicator does not come on when the DAC switch is pressed.
In the above cases have your vehicle checked by your Toyota dealer.
CAUTION
■Do not rely excessively on the downhill assist control system
It may not be able to maintain a low speed over road surfaces on which sliding can easily occur, such as extremely steep slopes or icy or muddy roads.
Rear differential lock system
Clutch start cancel switchExtension Module Malfunction (B1552,B158A,B15BA)
DESCRIPTION
These DTCs are stored when a malfunction occurs in the stereo component tuner
assembly.
DTC No.
DTC Detection Condition
Trouble Area
B1552
Internal malfunction of the navigation ECU
Stereo component tuner assembl ...
Radio Broadcast cannot be Received or Poor Reception
PROCEDURE
1.
CHECK RADIO AND DISPLAY RECEIVER ASSEMBLY
(a) Check the radio automatic station search function.
(1) Check the radio automatic station search function by activating it.
Result
Result
Proceed to
Automatic station ...
Air Inlet Damper Control Servo Motor Circuit (B1442/42)
DESCRIPTION
This No. 1 air conditioning servo assembly (fresh/recirculation damper) is controlled
by the air conditioning amplifier assembly and moves the air inlet damper to the
desired position.
DTC No.
DTC Detection Condition
Trouble Area
B1 ...