Description And Operation Parking Brake (page 8 of 15)

 
The parking brake has two warning indicators, one amber and one red, located in the speedometer of the instrument 
cluster. 
 

Amber Parking Brake Warning Indicator 

The amber parking brake warning indicator is continuously illuminated if there is a parking brake system fault. Operation 
of the indicator is controlled by a high speed Controller Area Network (CAN) bus signal from the parking brake module to 
the instrument cluster. 
 

Red Parking Brake Warning Indicator 

When the parking brake is applied, the red parking brake warning indicator is continuously illuminated while the ignition is 
on and for 3 minutes after the ignition is switched off. If the system is unable to comply with an apply or release request, 
due to a system fault, the indicator flashes. 
 
When the ignition is on and the indicator is not flashing, operation is controlled by a high speed CAN bus signal. When the 
ignition is off or when the indicator is flashing, operation is controlled by a hardwired signal from the parking brake module 
to the instrument cluster. 
 

Text Messages  

On vehicles with the high line instrument cluster, when there is a fault condition, illumination of the warning indicators is 
accompanied by a text message displayed in the message center. For additional information, refer to  

Instrument 

Cluster

 (413-01 Instrument Cluster) 

PARKING BRAKE MODULE 

The parking brake module monitors external and internal inputs and adjusts the tension of the brake cables to operate the 
drum brakes and provide the required parking brake function. 
 
The parking brake module is installed on a support bracket attached to the front of the spare wheel carrier. Two rubber 
mounts, installed on lugs on the underside of the parking brake module, locate in holes in the support bracket. The top 
corners of the parking brake module are secured to the support bracket with rubber mounts and flanged nuts. 
 
The main components of the parking brake module are: 
 

l

A Printed Circuit Board (PCB) incorporating the Application Specific Integrated Circuit (ASIC) for control of the 
parking brake.  

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An electric motor.  

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A gearbox.  

l

A spline shaft.  

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A force sensor.  

The spline shaft and the force sensor are connected together by a latch on the end of the spline shaft. The spline shaft 
rotates on the latch and moves axially in the gearbox. The latch and the force sensor slide in a channel in the body of the 
parking brake module. 
 
To apply or release the drum brakes, the parking brake module runs the electric motor, which drives the gearbox. The 
gearbox turns the spline shaft to increase or decrease the tension in the brake cables. The parking brake module 
monitors the load exerted by the brake cables using the input from the force sensor. 
 

Interior of Parking Brake Module 

2

Amber warning indicator (all except NAS)

3

Red warning indicator (NAS only)

4

Amber warning indicator (NAS only)