Fig 1: Identifying Functions/Components Controlled

Courtesy of VOLVO CARS OF NORTH AMERICA.

Sensors and functions which are different to previous types are marked in bold text .

Number	Component	Signal type/explanation
2/22	Air conditioning (A/C) relay	Connecting and disconnecting A/C compressor
2/23	Fuel pump (FP) relay	Signal for fuel pump (FP) on/off switch. In a collision where the SRS is deployed it also sends a signal to the Engine Control Module (ECM) to turn off supply to the fuel pump (FP).
2/32	System relay	Controlled by the Engine Control Module (ECM) provides sensors and functions with voltage supply.
4/28	Transmission Control Module (TCM)	For the signals transmitted between the engine control module (ECM) and the Transmission control module (TCM) refer to CAN communication.
4/50	Electronic Throttle Module (ETM)	For the signals transmitted between the engine control module (ECM) and the electronic throttle module (ETM) refer to CAN communication.
4/71	Electronic Fan Control Module	For the signals transmitted between the engine control module (ECM) and the electronic fan control module refer to CAN communication.
5/1	Central Electronic Module (CEM)	For the signals transmitted between the engine control module (ECM) and the central electronic throttle module refer to CAN communication.
7/15	Front heated oxygen sensor (HO2S) 1	Power supply for heating PTC element
7/82	Rear heated oxygen sensor (HO2S) 2	Power supply for heating PTC element
7/103	Rear heated oxygen sensor (HO2S) 3	Power supply for heating PTC element
7/104	Front heated oxygen sensor (HO2S) 4	Power supply for heating PTC element
8/6 - 8/11	Injectors	Controlled individually (sequentially).
8/18	Canister purge (CP) valve	Continuously controlled, it controls the flow from the EVAP canister to the engine intake side.
8/19	Continuously Variable Valve Timing control valve (CVVT)	Continuously controlled, it controls camshaft setting. On turbocharged engines it controls the exhaust camshaft and on normally aspirated it controls the intake camshaft.
8/28	Turbocharger (TC) control valve	Controls turbocharger (TC) boost pressure, see the information on turbocharger (TC) control system.
8/44	Fresh air valve, Canister purge (CP)	The valve is either off or on and opens or closes the canister fresh air intake during a leak diagnostic.
20/3 - 20/8	Ignition coil/power stage for cylinders 1 - 6	Separate ignition coil with integrated power stages for each cylinder. Gives shorter charging interval and more power.
	Malfunction indicator lamp (MIL) USA/CDN = Check Engine Other = engine symbol	The lamp lights up for faults affecting the emissions. The lamp flashes for misfires which cause risk of damage to the catalytic converter. Can also light up when requested by the Transmission Control Module (TCM) and the electronic throttle module.

When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

• You smell fuel, burning insulation, or see smoke.

• Brakes feel soft, pull hard to one side, or make grinding noises.

• The engine overheats, stalls repeatedly, or misfires under load.

• You are missing required tools, torque specs, or safe lifting equipment.

• You are not confident in the next step or safety outcome.

Safety Warning

Functions/components controlled

Use the Manual With the Right Hardware

When to See a Mechanic

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