Function test
WARNING: This page is about a different car, the 2004 Volvo S40, 2003 Volvo S40, 2002 Volvo S40, 2001 Volvo S40, and 2000 Volvo S40. However, it is still accessible from the selected car via links, so may be relevant.
The diagnostic is divided into different phases in which the components involved are tested before the actual leak diagnostic begins. The diagnostic is cancelled and a diagnostic trouble code (DTC) is stored if a fault is detected in any of the phases. The diagnostic test works as follows:
- The system must be depressurized. The control module checks that the pump diaphragm is in the resting position. Diagnostic trouble code (DTC) ECM-65, faulty signal, is stored if the control module registers that the position is active
- When the engine is started, a vacuum is generated in the intake manifold. The three-way valve opens a connection to the intake manifold via the non-return valve. The diaphragm is moved to the activated position by the vacuum. Diagnostic trouble code (DTC) ECM-65, high signal, is stored if the control module registers that the diaphragm is still in the resting position
- The three-way valve closes the connection with the intake manifold. The non-return valve closes. A connection to the atmospheric pressure opens. The spring-loaded diaphragm must then return to resting position. Diagnostic trouble code (DTC) ECM 65, low signal, is stored if the diaphragm does not return to the resting position.