Fuses Controlling Engine Management

Electrical system

The S70/V70 electrical system has been modified and many engine management system components have been protected with fuses, see Service Wiring Diagrams S70/V70 1997. This means that blown fuses can cause diagnostic trouble codes (DTCs), driveability problems and starting problems.

These fuses are located in a central electrical unit by the left spring strut turret in the engine compartment. The main relay (2/32), pulsed secondary air injection system (PAIR) pump relay (2/53), starter relay (2/35) and air conditioning (A/C) relay (2/22) are also located there.

Fuse 11B/1 is connected to the engine control module (ECM) power supply #A26 and the fuel injection system main relay.

Fuse 11B/2 is connected to the injectors, idle air control (IAC) valve, mass air flow (MAF) sensor and engine control module (ECM) power supply #A27. A blown fuse can store diagnostic trouble codes (DTCs) EFI-121, EFI-223, EFI-245 and EFI-1X5 or a combination of these.

Fuse 11B/3 is connected to fuel pump (FP) relay and ignition discharge module (IDM).

Fuse 11B/4 is connected to transmission control module (TCM) power supply #A30. A blown fuse can store diagnostic trouble code (DTC) EFI-335.

Fuse 11B/5 is connected to the canister purge (CP) valve, front and rear heated oxygen sensors (HO2S), pulsed secondary air injection system (PAIR) solenoid valve, EVAP canister shut-off valve, turbocharger (TC) control valve, pulsed secondary air injection system (PAIR) pump relay, air conditioning (A/C) relay, and crankcase ventilation PTC element. A blown fuse can store diagnostic trouble codes (DTCs) EFI-153, EFI-212, EFI-225, EFI-242, EFI-445, EFI-447, EFI-521, EFI-522, EFI-541 and EFI-616 or a combination of these.

Fuse 11A/1-11A/8 are main fuses.

Fuse 11A/1 is connected to the engine cooling fan (FC) relay.

Fuse 11A/3 is connected to the pulsed secondary air injection system (PAIR) pump relay and starter relay.

Fuse 11A/6 is connected to the air conditioning (A/C) relay.

Fuse 11A/8 is connected to fuse 11B/1 and via the main relay to fuse 11B/2-11B/5.