How to get, clear and understand Volvo diagnostic codes on 1992-1995 Volvos. To start, the Ignition key must be in position II, engine not running. Open the hood. Locate the two diagnostic sockets just inboard of the washer fill cap.. Volvo S40 owners have reported 42 problems related to electrical system (under the electrical system category). The most recently reported issues are listed below. Also please check out the statistics and reliability analysis of Volvo S40 based on all problems reported for the S40.. Find new & used Volvo cars for sale locally in Australia. Find great deals on Volvo cars on Gumtree Australia..