Typical Mazda6 components

7

An important earth connection, adjacent to the left-hand front suspension strut, may be suffering from corrosion. In this case, separate the joint and clean and reassemble all components, coating them with silicone protectant.

8

This is the wiring connector plug for the exhaust gas recirculation (EGR) valve, mounted on the left-hand end of the cylinderhead. It sends exhaust fumes back through the engine, effectively recycling them to reduce nitrogen oxide (NOX) emissions.

9

Tucked away beneath the bulkhead at the rear of the engine compartment, on the left-hand side, is the charcoal canister. Its job is to capture potentially harmful fuel vapour emissions to prevent them reaching the atmosphere.

10

Located at the rear of the engine bay, behind the battery and way down beneath the charcoal canister shown in photo 9, is the separate ECU for the power steering system.

11

The circled component is the variable valve timing solenoid. This relies on clean engine oil to function correctly. It links the engine’s electronic control system with the mechanical valve set-up, enabling valve timing to be altered for maximum efficiency.

12

The injectors are an electromagnetic type – they are held closed by a spring, but opened by an electromagnet built into the injector body. The ECU determines how long the injector stays open.

13

The camshaft sensor, seen in the centre of this photo, is fitted at the left-hand end of the cylinderhead and monitors the camshaft position. It sends the information to the ECU, which then determines fuelling and ignition requirements.

14

The four ignition coils are all readily accessible, being positioned in a line along the top of the engine. It’s essential to be careful with the coil connectors and renew them in sets if a failure occurs.

15

Bolted to the right-hand suspension tower are further earth connections. These must be clean and securely attached; check these aspects and if necessary, dismantle, clean and reassemble the joints, coating them with a silicone protectant.

16

The ABS Ecu/modulator controls the anti-lock braking system and, if defective, can trigger illumination of dash warnings. The ABS controller receives input signals from the wheel speed sensors to identify if there is a wheel slip on any wheel.

17

An important interior fusebox is located near the left-hand front door pillar/kick panel. Usually hidden beneath a plastic cover, this is less vulnerable to moisture ingress than the underbonnet fuse/relay box, but is still worth inspecting.

18

The accelerator position sensor, which transmits data about the position of the accelerator pedal to the ECU to adjust appropriate fuelling, is integrated with the pedal assembly and mounted just ahead of it.

19

The ignition key assembly is vital to correct operation of the security system to allow the engine to fire, housing a microchip that’s paired to the vehicle. If your scan tool is equipped for it, check via live data that the immobiliser turns off when the key is inserted. When renewing the fob battery, take care as the chip can easily fall out.

20

The diagnostic socket is positioned vertically, adjacent to the lower edge of the right-hand side of the fascia assembly above the foot pedals.

21

This screenshot on the SOLUS Edge is showing passive fault codes stored in the ECU. This means that a code has been stored, but the fault was not permanent so the relevant warning lamp has not been illuminated. On some code readers it’s possible to get the exact date and time the code was stored, along with data such as engine temperature.

22

This live data screenshot shows details relating to the operation of the fuel pump. It can also give the operator much other useful information about what is happening as it happens with regard to a variety of engine aspects.