Central Control Unit (CCU) (page 4 of 4)

CONTROL UNITS

DESCRIPTION AND OPERATION

86-3-5

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:

l

Hold the rear fog guard lamp switch on.

l

Turn the ignition off.

l

Turn the ignition on.

l

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

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).

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