Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
2009 Audi S4 AutomaticFACTORY OEM SERVICE PROCEDURE
4.2L - Fuel Injection And Ignition, Engine Code(S): BHF
- 24 Multiport Fuel Injection (MFI)
- Motronic injection system, servicing
- Safety precautions
- Rules for cleanliness
- Technical data
- Component locations overview
- Notes
- MIL exhaust emissions warning lamp
- Exhaust emissions warning lamp (CHECK)
- EPC warning lamp
- Evaporative Emission (EVAP) Canister Purge Regulator Valve -N80-
- Installation location of Throttle Position (TP) sensor -G79- Sender -2- for accelerator pedal position -G185-
- Installation location of Brake light switch -F-, Brake Pedal Switch (cruise control/Diesel Direct Fuel Injection) -F47- and Clutch Vacuum Vent Valve Switch -F36-
- Installation location of Fuel Pump (FP) Relay -J17-
- Installation locations in plenum chamber electronics box
- Installation location of engine control module in plenum chamber electronics box
- Assignment of holder for connectors (right side)
- Connector console beneath coolant expansion tank
- Rear view
- Front view
- Secondary Air Injection (AIR) Pump Motor -V101-
- Leak detection pump (LDP) -V144-
- Fuel pressure regulator and holding pressure, checking
- Injection quantity, leakage, and spray pattern of injectors, checking
- Wiring and component check using test box V.A.G 1598/31
- Motronic Engine Control Module (ECM) -J220-, replacing
- Intake manifold, assembly overview
- Intake manifold, removing and installing
- Lock carrier in service position, overview
- Heated Oxygen sensor (HO2S) before catalytic converter, bank 1 (right), removing and installing
- Heated Oxygen sensor (HO2S) before catalytic converter, bank 1 (right), removing and installing
- Heated Oxygen Sensor before catalytic converter, bank 2 (left), removing and installing
- Heated Oxygen Sensor (HO2S) after catalytic converter, bank 1 (right), removing and installing
- Heated Oxygen Sensor (HO2S) after catalytic converter, bank 2 (left), removing and installing
- Motronic injection system, servicing
- 28 Ignition/Glow plug system
Factory Service Tools
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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.