Test your BMW's fuel pump, fans and injectors

When a part may have failed, the quickest check is to make it run: does the fuel pump hum, does the radiator fan spin, does each injector click? BMW's dealer tools ask the module to drive the part for a few seconds, and AutoLingo for BMW does the same from the Service tab. The module runs the part for about 20 seconds, then takes it back by itself, so nothing is left running.

The tests, as the app names them: Test the fuel pump, Test the cooling fan, Test the e-box fan, Test the electric water pump, Test the purge valve, Test the thermostat, Test the secondary-air pump, Test the secondary-air valve, Test the exhaust flap, Test the DISA (intake flap), Test the check-engine light and Test the injectors.

Which BMWs

Which tests you get depends on your car's modules: mostly the engine module's, and the fuel pump module's where the car has one. Each test drives a part, so it runs on the cars we've confirmed it on (below); on others the app shows it as Coming until we have.

Confirmed on a real car: BMW 3 Series (E90) (October 2026), BMW X5 M (F85) (October 2026)

Service jobs that change the car come to each BMW once we've confirmed them on a real car like it; until then the app shows them as Coming. Every update is free.

Before you start

  • Ignition on, engine off: the module won't run most tests with the engine running, and the fan test won't run while the engine is hot (over about 95 °C, 203 °F).
  • Keep hands, clothing and tools clear of the fan: its blades spin up.
  • The AutoLingo for BMW adapter plugged in and connected.

Step by step

  1. Open the Service tab and open “Component tests”. With several modules, each has its own list.
  2. Tap Start next to a test, for example “Test the fuel pump”. A part with several options (each injector, or fan speeds) has Open instead, with a button for each.
  3. Read the instructions and tap Start.
  4. Watch or listen: the part runs for about 20 seconds, then stops on its own. Stop ends a test early.

Good to know

  • If nothing happened, the module refused the test: check the ignition is on and the engine off (and cool, for the fan), then run it again.
  • The injector test keeps the fuel pump off, so no fuel sprays: each injector just clicks.
  • A part that doesn't run when tested points to the part, its wiring or its relay or fuse. Read the Faults tab too: the module often has a fault stored for it.

More how-tos: Check if your BMW is ready for an emissions inspection · Check your BMW's battery health · Register a new battery in your BMW · Read and reset your BMW's service intervals (CBS) · Open your BMW's electric parking brake for a rear brake job · Set your BMW's clock from your phone