Typical Volvo V40 components

6 This important earth (ground) point is found on the left-hand front suspension turret. This one is in excellent condition, but if you have doubts about the cleanliness or security of the joint, unbolt the connection, clean, reassemble and protect with silicone grease. 7 Found right at the rear of the engine compartment, and beneath the overhanging bulkhead, is the brake servo pressure sensor. Inspect the cables and plug/socket connector assembly for condition, cleanliness and security. 8 Tucked away within the rear part of the engine bay, approximately halfway across the car, is the pressure sensor for the air-conditioning system. Check the state of the cables and connections, in terms of contamination and condition. 9 Both the turbocharger and the Diesel

Particulate Filter (DPF) are hidden away, located deep down at the rear of the engine compartment, and difficult to reach, or even to see clearly. The turbocharger requires a constant supply of clean engine oil to survive. 10 The fuel rail and its pressure sensor

(that provides the ECU with data relating to the fuel pressure within the rail) mounted on the end of the rail, towards the right-hand side of the car, are both at the front of the engine and are readily accessible. 11 The fuel injectors are positioned at the top of the motor and are easy to reach for attention/renewal. The injectors bear code numbers, and when new ones are installed they need to be ‘introduced’ to the engine using suitable diagnostic equipment.

12

Located just beneath the fuel rail, at the front of the engine and not difficult to check and to reach, are the glow plugs (two of which are visible in this shot). They need to function correctly to ensure easy starting, especially at low ambient temperatures.

13

As with many components around the V40’s engine, the air mass (MAF) sensor, fitted within the intake trunking, is easy to reach and to remove if/when required. The sensor’s job is to feed to the ECU information on the mass/rate of air flowing though the system.

14

The large air filter housing is prominently positioned at the top of the engine, towards the left-hand side. The lid is removed after releasing and removing the array of screws around its perimeter. When renewing the air filter, always clean the inside of the housing.

15

The Mass Absolute Pressure (MAP) sensor is located at the top of the engine, and is easy to reach and to renew if required. It supplies the ECU with information about the pressure within the inlet manifold at all times, helping to determine fuelling levels.

16

A vital part of the fuel supply system on this Volvo is the high-pressure pump. Check for physical deterioration and fuel leaks. Live data relating to fuel pressure and volume control, etc, can be accessed using diagnostic equipment such as the Launch X431 Euro Tab II.

17

The key fob assembly needs to be sound and with its battery in top condition. Renewing the internal battery is an important part of the maintenance programme on this V40. Edward recommends renewing the fob batteries every two years, as part of the car’s servicing schedule.