2007 KIA CARNIVAL Workshop Manual

2007 > 2.7L V6 GASOLINE >
Description
The VRS (Variable Rack Stroke) is the system that controls the rack stroke using the operating unit installed on both
ends of the gear box. Normally the VRS system keeps switching OFF and the rack stroke stays increased, so the
vehicle's turning radius becomes reduced. On the other hand, when fitting the snow chains in winter season, the VRS
switch must be turned ON and the VRS system will prevent interference between the snow chains and the vehicle by
decreasing the rack stoke.
Operating principle
When switching the VRS system ON, the DC motor in the VRS operating unit rotates the gear stopper by 90 degrees
and the gear stopper stops the stop protrusion from entering as shown in the illustration below. This operation reduces
the maximum steering angle by decreasing the rack stroke. When switching the VRS system OFF, the gear stopper
returns to original location and the rack stroke also returns to normal.

2007 > 2.7L V6 GASOLINE >
TROUBLE SHOOTING
Symptom Probable cause Remedy
There is no change made in rack
stroke even though turning the VRS
switch ON or OFF. a.
VRS operating unit
b. VRS control module
c. VRS switch a.
Inspect the VRS operating unit.
b. Check Input/ output signal of the
VRS control module.
c. Inspect connection of the VRS
switch.
LED is not illuminated even though
turning the VRS switch ON. VRS switch a.
Inspect connection of the VRS
switch.
b. Check the LED for damage.
Inspection of the rack stroke
1.Is the rack stoke (the maximum steering angle) changed when pressing the VRS switch ?
▶ The VRS system is in normal condition.
▶ Go to step 2.
2. Measure the resistance of the VRS operating unit.
(1) Disconnect the VRS operating unit connector.
(2) Measure the resistance between the terminal No.1 and No.2.
Repeat the terminal No.3 and No.4.
Is the measured resistance within standard value ?
4 ~ 20 Ω → Normal condition (standard value)
1 Ω or below → Short
100 Ω or above → Open circuit
▶ Go to step 3.
▶ Repair or replace the power steering gear box.
3. Measure the output voltage of the VRS control module.
(1) Disconnect the VRS control module connector.
(2) Connect 9 ~ 15 V power between the terminal No.3 and No.4.
(3) Measure the output voltage (to DC motor) between the terminal No.5 ~ 8.
Is the voltage measured within standard value ?
Supplied power Measured output voltage

Supplied powerStandard valueVRS CM failure
9 V 8 V or above Below 8 V
12 V 11 V or above Below 11 V
15 V 14 V or above Below 14 V
▶ Inspect connection of connectors and harness for the VRS system.
▶ Replace the VRS control module.
1. Is the LED on the VRS switch illuminated when turning the VRS switch ON?
▶ The VRS switch has normal condition.
▶ Go to step 2.
2. Inspect the VRS switch connector.
(1) Disconnect the VRS switch connector.
(2) Connect 12 V power between terminal No. 1 (+) and No.3 ( - ).
Check if the LED is turned ON or OFF by pressing the VRS switch.
Is the LED turned ON or OFF when pressing the VRS switch ?
▶ The VRS switch is in normal condition.
▶ Repair or replace the VRS switch.

VRS Control Unit

2007 > 2.7L V6 GASOLINE >
Description
The VRS control module (A) controls the DC motor in the VRS operating unit according to signal of the VRS switch
(ON or OFF) and is mounted behind the center fascia.

VRS Operating Unit

2007 > 2.7L V6 GASOLINE >
Description
The VRS operating unit installed on both ends of the steering gear box can change the rack stoke by changing angle
of the gear stopper.