Dead battery, very low charge, or bad battery contacts.

Check the battery charge. If low, recharge it or replace it. Also, clean the battery connections.

Blown fuse.

Check all fuses that power the ECU, Alarm or Immobilizer system. Sometimes, there are 3 to 5 fuses to check.

Bad starter relay.

Check that the starter relay is working properly.

Seized starter motor, or not working properly.

Try powering the starter motor directly to test if it can crank the engine.

Faulty ignition switch.

Ensure that all contact points on the ignition switch are spreading power and ground throughout the car.

Broken, short-circuited, dirty or corroded Control Unit harness connectors causing bad contacts.

Ensure all the Control Unit harness connectors are not broken or have a short-circuit problem. Also, clean any rust or corrosion. Ensure a tight fit.

Clutch pedal switch on Manual Transmission cars not engaged or faulty.

Ensure that the clutch pedal switch signal is present when trying to start the car.

Electronics are missing an additional essential ground point.

Check that all the car's ground points have clean and tight

connections, and no short circuits.

The car’s immobilizer “Drive-Block” is activated (Porsche 993 models).

Disable the "drive-block" system by pressing on the key fob button.

The alarm or the car might be activated.

See if there is a way to disable or bypass the alarm system.

The EWS and DMR are not in sync (BMW models after 1995).

With a BMW compatible scanner, perform a DME to EWS alignment/synch.



Some of the testing procedures described in this guide could be dangerous if done improperly. We recommend that they are performed by an ASE certified mechanic




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