Body Control Module: Description and Operation

Central Control Unit (CCU)
The CCU is plugged into the back of the passenger compartment fusebox below the fascia. Two connectors provide the interface between the CCU and the passenger compartment fusebox and three connectors provide the interface between the main harness and the CCU. The CCU is responsible for controlling the following functions:
^ Transit mode.
^ Anti theft alarm.
^ Windscreen wipers.
^ Courtesy lamp delay.
^ Door open warning lamp.
^ key in alarm.
^ Rear fog guard lamps.
^ Lights on alarm.
^ Seat belt warning.
^ Handbrake warning.
^ Rear screen wiper.
^ Tail door window.
^ Heated rear window.
^ Heated windscreen.
^ Tail door latch.
^ Window lift.
^ Seat heating.
^ Daytime running lamps.

Some of the features controlled by the CCU are market selectable and may not be operative or available in specific markets. TestBook can be used to configure the CCU to enable/disable market selectable features, tailor anti theft alarm features to customer requirements and can also interrogate the CCU for stored fault codes and alarm triggers. TestBook is connected to the CCU via the diagnostic socket which is located in the passenger footwell.

Transit Mode
The transit mode feature is to minimize battery usage when the vehicle is being stored or transported prior to sale.
When the CCU is programmed in the transit mode, the following functions are disabled:
^ RF receiver.
^ Tail door actuator.
^ Tail door window.
^ Central Door Locking (CDL).
^ Interior lamps.

If the ignition is switched to position II the CCU buzzer will sound an alarm to warn that the vehicle is in transit mode. The dealer can remove the transit mode feature and program the CCU to the applicable market specification at the Pre Delivery Inspection (PDI) using TestBook/T4.

Anti Theft Alarm System
The CCU controls the Central Door Locking (CDL) and the alarm system for the vehicle. These are integrated into the vehicle security system, which also includes engine immobilization.

Windscreen Wipers
The CCU controls the intermittent wipe and programmed wash/wipe of the windscreen wipers.

Courtesy Lamp Delay
The CCU controls the delay function of the interior courtesy lamp. The courtesy lamp can also be switched on using a manual switch on the lamp unit.

Door Open Warning Lamp
The CCU illuminates a warning lamp on the instrument pack if the driver's door, passenger door(s), tail door or bonnet is open while the ignition is on.

Key in Alarm
The CCU will sound a continuous warning on the integral sounder when the driver's door is open while the key is in the ignition switch at position 0 or I. This is to prevent the driver inadvertently leaving the vehicle with the key in the ignition switch.

Rear Fog Guard Lamps
The CCU controls the operation of the rear fog guard lamps via a rear fog guard lamp relay. The guard lamps operate only if the headlamps are on and the ignition switch is in position II. When the headlamps or the ignition are switched off the CCU automatically switches off the guard lamps.

Lights On Alarm
The CCU will sound a continuous warning on the integral sounder when the driver's door is open while the side lamps or head lamps are on and the ignition is off. This is to prevent the driver inadvertently leaving the vehicle with the side lamps or headlamps on.

Seat Belt Warning
When the ignition is switched on the CCU performs a bulb check of the seat belt warning lamp in the instrument pack for approximately 5 seconds, or until the ignition is switched off or the engine cranks. To prevent a driver inadvertently driving without fastening their seat belt, if the driver's seat belt is unfastened when the ignition is switched on the CCU sounds a warning on the integral sounder for approximately 5 seconds and keeps the seat belt warning lamp illuminated after the bulb check.

Handbrake Warning
A warning lamp to warn the driver that the handbrake is on is located in the instrument pack. The warning lamp illuminates when the ignition is on and the handbrake is applied. In some markets the CCU performs a bulb check of the warning lamp for approximately 5 seconds at the beginning of each ignition cycle.

Rear Screen Wiper
The CCU controls the rear screen wiper via a forward and a reverse relay. The wiper will not operate if the tail door window is lowered or not calibrated or, on 3 door models, if the roof is open (soft back) or removed (hard back).

Tail Door Window
The CCU controls the lowering and raising of the tail door window, which can be opened using a console switch or the remote handset. On 3 door models, opening/removal of the roof will automatically lower the window. The window can be raised using the console switch or the vehicle key in the tail door key barrel. When the tail door is opened, the tail door window lowers to a 'clear of seal' position. When the door is closed the window automatically rises to its fully up position.

Heated Rear Window (HRW)
The CCU controls the operation of the HRW. When the HRW switch, located on the center of the fascia, is pressed and released a signal is sent to the CCU. With the ignition on, the oil pressure sense present (i.e. the engine running), the tail window not lower than the 'clear of seal' position and, on 3 door models the roof closed/on, the CCU will grant the HRW on. The CCU will energize the HRW relay for approximately 15 minutes after which the CCU will de-energize the HRW relay. A warning lamp in the HRW switch shows when the HRW is operating.

If the switch is pressed before the timed 15 minute period, the CCU will immediately switch off the HRW. Removal of any of the input signals to the CCU will also stop HRW operation. The HRW switch will require re-selection to operate again.

Heated Windscreen
Operation of the heated windscreen is controlled by the CCU and a non latching switch on the center console. The switch contains a LED which illuminates while the heated windscreen is on. Power for the heater elements is supplied by a relay, on the inboard side of the E-box, controlled by the CCU. Two fuses next to the relay provide electrical protection for the heater elements.

When the heated windscreen switch is pressed, the CCU energizes the heated windscreen relay, provided the engine is running, to connect a battery power feed to each of the heater elements. The feed to the RH heater element also provides the power feed to illuminate the LED in the heated windscreen switch.

The CCU de-energizes the heated windscreen relay after approximately 5 minutes, when the switch is pressed again, or if the engine stops.

Tail Door Latch
The tail door latch is operated by a tail door lock motor controlled by the CCU. When the CCU receives an open request from the tail door handle switch, it energizes the tail door lock motor for 440 ± 40 milliseconds provided the vehicle is in the following configuration:
^ The door locking system is in the unlocked state.
^ The alarm system is disarmed.
^ Road speed is less than 3 ± 1 mph (5 ± 1.5 km/h).

The position of the ignition switch has no effect on the operation of the tail door lock motor.

Window Lift
Power for side door window operation is supplied from the window lift relay and, on 5 door models, the auxiliary relay, both located in the passenger compartment fusebox. The CCU controls the relays, which are energized while the ignition switch is in position II and for approximately 40 seconds after the ignition is turned off.

Seat Heating
Power for the seat heaters is supplied from the auxiliary relay in the passenger compartment fusebox. The CCU controls the auxiliary relay, which is energized while the ignition switch is in position II and for approximately 40 seconds after the ignition is turned off.

Daytime Running Lamps
The daylight running feature is controlled by the CCU via two daylight running relays located inboard of the passenger compartment fusebox. The CCU switches the relays, to illuminate the dipped beams, side lamps, tail lamps, rear number plate lamp and side marker lamps, when the following conditions are met:
^ The engine is running.
^ Gearbox selector lever not in Park.
^ Headlamps not selected on.

The CCU and the daylight running relays are also used to operate the head/side lamps when they are selected on using the lighting switch on the LH column stalk. The lamps then operate as on non daylight running vehicles, and remain on when the gearbox is in Park and when the engine is switched off.

Self Test Mode
The CCU can be put into a self test mode to enable the inputs and outputs to be tested for correct functionality without the need for TestBook/T4. To put the CCU into the self test mode the vehicle must be unlocked and disarmed, then the ignition turned on and the following sequence completed within 4 seconds:
^ Hold the rear fog guard lamp switch on.
^ Turn the ignition off.
^ Turn the ignition on.
^ Release the rear fog guard lamp switch.

On successful entry to the self test mode the CCU simultaneously operates the sounder and illuminates the courtesy lamps for 0.8 second.

When testing an input, e.g. a door open switch, on successful receipt of the input the CCU also simultaneously operates the sounder and illuminates the courtesy lamps for 0.8 second.

Outputs are tested in sequence using the CDL lock switch to progress through the outputs. A CDL unlock request repeats the last test. Outputs are either operated continuously until the CDL lock switch is released, or operated with a pulse.

Self Test Outputs Sequence

Output Test Type
Rear fog lamps Continuous
Lock Pulsed for 0.76 second
Superlock Pulsed for 0.76 second
Unlock Pulsed for 0.76 second
Front wiper Continuous, then self parks
Alarm LED Continuous
Volumetrics Continuous
Horn Pulsed for 0.8 second
Heated windscreen Pulsed for 0.8 second
Heated rear window Pulsed for 0.8 second
Tail window down Pulsed, drives fully down
Tail door actuator Pulsed for 0.44 second
Tail window up Pulsed, drives fully up
Rear wiper Continuous
Hazard lamps Continuous
Door open warning Continuous
Seat belt warning lamp Continuous
Handbrake/Brake warning lamp Continuous
Daytime running lamps Continuous

Self test mode is cancelled when the ignition is turned off, if oil pressure is sensed (i.e. engine running) or if the vehicle speed exceeds 0.6 mph (1 km/h).

Radio Frequency (RF) Receiver
The RF receiver is part of the security system and relays data from the remote transmitter (plip) to the CCU. The RF receiver is located on top of the instrument pack, between the housing and the face plate.

Immobilization ECU
The immobilization ECU controls operation of the starter motor to provide the engine immobilization function of the security system. The immobilization ECU is secured to the rear of the fascia near the vehicle center-line.

Supplementary Restraint System (SRS) Diagnostic Control Unit (DCU)
The SRS DCU controls the operation of the vehicle's airbags and seat belt pretensioners. The SRS DCU is attached to the transmission tunnel below the heater assembly.

Electronic Automatic Transmission (EAT) ECU (Automatic Gearbox Models Only)
On automatic gearbox models, the EAT ECU controls gear changing and torque converter lockup. The EAT ECU is installed in the Environmental (E) box in the engine compartment.

Engine Control Module (ECM)
The ECM controls all aspects of engine operation and interfaces with the security system during engine starting. The ECM is installed in the E-box in the engine compartment.

Cooling Fan ECU
The cooling fan ECU controls the speed of the two cooling fans. The cooling fan ECU is installed in the rear upper left corner of the cooling fan housing.

Anti-lock Braking System (ABS) Modulator
The brake system incorporates an ABS ECU that controls the operation of the hydraulic modulator to provide the ABS, electronic brake force distribution, traction control and hill descent control functions. The ABS ECU is attached to the hydraulic modulator, which is installed in the front right corner of the engine compartment.

Folding Door Mirror ECU (Some Markets)
In some markets folding door mirrors are installed and these are controlled by the folding door mirror ECU. The folding door mirror ECU is installed:
^ Up to 2002 MY, on the transmission tunnel, below the center console.
^ From 2002 MY, on the front passenger side 'A' post

Window Lift ECU
The window lift ECU is installed to provide one shot opening of the driver's door window. The window lift ECU is installed on the driver's side A post, level with the lower edge of the fascia.

Cruise Control Interface ECU (Some KV6 and Td4 Models)
Where fitted, the cruise control interface ECU provides the interface between the cruise control operating system and the cruise control switches on the steering wheel. The interface ECU is installed under the RH front seat.

Cruise Control ECU (Some KV6 Models)
Where fitted, the cruise control ECU controls the vacuum system that operates the throttle. The cruise control ECU is installed under the RH front seat next to the cruise control interface ECU.