Fuel pressure control, diagnostics

WARNING: This page does not describe the selected car, but rather 7 other vehicles, including the 2007 Volvo V70, 2006 Volvo V70, 2005 Volvo V70, 2004 Volvo V70, and 2003 Volvo V70. However, it is still accessible from the selected car via links, so may be relevant.

General

The fuel pump control module has no functions for diagnostics. Fuel pressure control components and functions are diagnosed by the engine control module (ECM).

The following components and functions are diagnosed by the engine control module (ECM). Diagnostic trouble codes (DTCs) can be stored for each component and function:

Fuel pump control module , a diagnostic checks the power supply. A diagnostic trouble code (DTC) will be stored and the fuel pump will not work if there is no power supply to the fuel pump control module
Fuel pressure sensor with temperature sensor, a diagnostic checks the pressure and temperature signals to see if they are outside the normal operating range of the sensor. If a fault in the fuel pressure sensor is detected, the fuel pump (FP) will run at a predefined power and the pressure is governed by the by-pass valve in the fuel tank
Fuel pressure , the engine control module (ECM) compares the requested pressure with the measured pressure (signal from the fuel pressure sensor). If the measured pressure deviates excessively from the requested pressure, or if the pressure pulses, a diagnostic trouble code (DTC) will be stored for incorrect fuel pressure. The diagnostic is not active if a diagnostic trouble code (DTC) for the fuel pressure sensor is stored. A diagnostic trouble code (DTC) for fuel pressure will be stored if there is a fault in the fuel pump
Communication cable. The engine cannot be started if there is a fault in the communication cable between the engine control module (ECM) and the fuel pump control module. A diagnostic trouble code (DTC) will be stored for the fault.

For further information about diagnostic trouble codes (DTCs), see Information, diagnostic trouble codes (DTCs) in VIDA.

Components and functions which cannot be diagnosed:

If there is a fault in the by-pass valve in the tank unit, the starting process of the engine will take longer if the valve is leaking fuel when the fuel pump is off. If the valve does not open when there are pressure peaks in the fuel system, engine operation will be affected negatively, especially after engine braking. The fault can also cause rough idling.