Differential: Overview Suzuki XL7 I

Scheme 1

The rear differential assembly in this vehicle consists of an aluminum housing which contains a electric clutch/coupler and a differential. The differential fluid is only contained in the differential housing portion. The clutch and clutch housing are serviced as an assembly. The clutch housing also has no differential clutch control module (CCM).

The differential clutch control module has integrated active clutch control logic.

The clutch or coupling can provide torque to the rear differential under a wide range of driving conditions. It differs from past on-demand systems as it can preload the clutch during take off to provide a less likelihood of wheel slip. The clutch control module (CCM) is connected to the vehicle serial data stream via the control area network (CAN). It uses data stream information from the engine control module (ECM) and the ABS/stability control module. The CCM monitors such signals as individual wheel speeds, ABS/stability control active, throttle position or wheel torque request to determine mode of operation.

The fluid level range for proper rear differential assembly operation is 500 ml. New service replacement units will be shipped dry (without fluid). Fill new units with 500 ml of GL Synthetic fluid.

All-Wheel Drive Description and Operation

This vehicle is equipped with the Rear Differential Clutch Control Module for AWD Vehicles.

The vehicle is equipped with the following system and operation

1. System distributes torque evenly between the 2 rear wheels.
2. The system distributes torque to the rear wheels to enhance traction and improve vehicle handling performance.
3. The rear differential clutch control assembly contains a main clutch, pilot clutch, electromagnetic coil, rear wheel shaft, main cam, pilot cam.
4. The clutch control module operates by utilizing a clutch pack for transferring torque. The engagement mechanism consists of an electromagnetic coil and armature which modulates torque through a pilot clutch and thrust amplification device.
5. The rear differential has a micro computer which receives information from the clutch control module (CCM).
6. The CCM has an internal temperature sensor, which will maintain consistent and continuous temperature compensation for torque transfer from -40°C to +120°C. When the temperature of the module is determined to be beyond its limits, the CCM will temporarily disable the rear drive system and turn on the AWD Disabled message. When the temperature of the module is back within the limits, the CCM will enable the rear drive system.
7. If the vehicle is being driven very aggressively, and or an unexpected tire size has been used, the AWD disabled message will be turned on. This should not result in the replacement of CCM module.
8. The AWD disable message will be turned on if the mini-spare tire or a very small sized tire has been installed. This should not result in the replacement of CCM module.
9. The clutch coil receives current from the CCM which is used to modulate torque through the use of the engagement mechanism. The greater the current the greater the torque. The safe current range is between 0.1-3.0-amps. If the current range is not within those values we have DTCs that set and the Service AWD message will appear.
10. The module uses vehicle speed, steering angle, wheel slip, thermal compensation, and chassis control intervention to determine current. These are messages on GMLAN from other modules.
11. Replace the CCM, the CCM needs to be configured for the clutch control calibrations. The connector on the clutch (that plugs into the CCM) will have a 2 digit value. Use that 2 digit value to program the CCM using the Tech 2.
12. Voltage for our module is between 5-24 volts. We set a low voltage code but not a high voltage code as we can withstand a voltage up to 24 volts.
13. Displays 2 messages in DIC or IP. Amber AWD Disabled (All Wheel Drive Off) - DIC Service All Wheel Drive.

Circuit/System Description

The rear differential clutch control module (CCM) provides a power and ground switching circuits to the (AWD) coil.

The coil receives current from the CCM through PWM low side driver, and converts that signal into torque through the clutch to the rear tires when all wheel drive (AWD) is requested.

The Rear Differential Clutch Control Module (CCM) provides a power and ground circuits to the temperature sensor. When the temperature of the module is determined to be beyond its limits, the CCM will temporarily disable the rear drive system.

The Rear Differential Clutch Control module (CCM) detects an internal malfunction.

The rear differential clutch control module (CCM) is required to have the correct calibration data (matching ID) stored in the memory from the AWD coupling control, and is part of the programming used to perform all wheel drive functions.

The Rear Differential Clutch Control module (CCM) receives messages from other modules over GMLAN which are needed to perform all wheel drive functions

The instrument panel cluster (IPC) illuminates the AWD Disabled indicator by supplying ground to the lamp. The Rear Differential Clutch Control Module (CCM) sends a serial data messages to the IPC, in order to command the indicator ON or OFF.

Test Description

The number below refers to the step number on the diagnostic table.

1. 2. This step determines whether the failure is the result of a faulty rear differential clutch control module or the IPC.

VEHICLE DTC INFORMATION TABLE