Central Electronics Box: Description and Operation

CAUTION: There are no fuses or other safeguards between the battery voltage and the control modules. Therefore always switch the Ignition off and wait for 60 seconds or disconnect battery before removing any control module, otherwise there is a risk of the module being destroyed.





The control module box is located in the engine compartment. It is designed to hold up to three electronic control modules.

These control modules are used for the ignition and fuel systems and the gearbox (AW 50-42) in automatic models.

The control module box protects the control modules, keeps signal leads short and minimizes the number of junctions, so increasing reliability.

Each control module has two connectors: one connected to the engine wiring harness and the other to the engine compartment wiring harness.

The control units are easy to remove and install, as they are fitted with guides which ensure they marry up correctly. A lever is provided to help insert and remove control modules from connectors. This lever also locks the module physically to the connectors.

The control module box has its own cooling system to keep the electronics systems at the right temperature.

Air from the car's AC system is piped and passes through the control module box. It then passes out via a plastic pipe running from the box cover, emerging between the fan casing and coolant where there is a partial vacuum. An earlier version took coolant air from the front of the car via an air filter. Change paper filters every 45 000 km (US/Can 48 000 km/30 000 miles).

If there is insufficient cooling for any reason, the ignition system will post a DTC (high PCB temperature).

If this occurs, check the coolant airflow and all pipes and joints.