Open-circuit, intermittent faults

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.

Fig 1: Checking For Open Circuit

Courtesy of VOLVO CARS OF NORTH AMERICA.

An open-circuit in a cable will be indicated by the loss of a function (or functions).

Chafed and broken leads are common causes of faults.

For repair of wiring and terminals, see the appropriate Wiring Diagrams.

Checks:

Disconnect the connectors at both ends of the cable.

Check the cables visually according to Inspect terminals visually .

Connect an ohmmeter between the ends of the cable.

The ohmmeter should read approximately 0 Ω if there is no open-circuit in the cable.

Shake the cable lightly and pull on connectors during measurement to locate the damage.

If the reading is not correct. Replace the cable and/or continue according to Contact resistance and oxidation .

Fig 2: Identifying Control Module Installation

Courtesy of VOLVO CARS OF NORTH AMERICA.

Always check the control module and control module box connectors to ensure that their pins and sockets are not bent or damaged, this may cause faults.

Check pins and terminals particularly carefully.