BMW 12131703228 Ignition Coil

Note the radio security code, then disconnect the negative battery cable. Locate the ignition coil. With the ignition OFF, disconnect the ignition lead from the coil tower. Label and remove the wires from the terminals marked 15 (+) and 1 (-). Note that the high voltage wire connector on the center tower terminal is referred to as 4. Using an ohmmeter, measure the primary resistance between the 15 (+) and 1(-) terminals. The primary winding resistance should be 0.82 ohms. Using an ohmmeter, measure the secondary resistance between the 15 (+) and the high-voltage output secondary winding terminal 4. The secondary winding resistance should be 8,250 ohms (8.25 Kilo ohms). Replace the coil if it's not within specifications. Reconnect the negative battery cable and enter the radio security code. For removal and installation, note the radio security code, then disconnect the negative battery cable. Locate the ignition coil. With the ignition OFF, disconnect the ignition lead from the coil lower. Label and remove the wires from the terminals marked 15 (+) and 1(-), then remove the high voltage wire connector from the center tower terminal. Remove the fasteners securing the ignition coil mounting bracket and remove the ignition coil. Installation is the reverse of the removal procedure, noting to enter the radio security code once the battery is connected.

A three-dimensional map is digitally stored in the ECM, and the initial ignition point is determined by the crankshaft sensor during cranking. The ECM continuously adjusts ignition timing based on operating conditions once the engine is running.

Remove the coil mounting nuts and pull the coil straight out.

Slide the rod-shaped ignition coil straight out of the spark plug hole.

Ensure the ignition is switched OFF.

For the M44 engine, which utilizes a combined ignition coil assembly with four separate coils, turn off the ignition. Disconnect the harness by turning the electrical connector counterclockwise. Assess the primary resistance between the specified terminals for each individual coil. For coil 1, check Pin 1-Pin 2. For coil 2, check Pin 6-Pin 2. For coil 3, check Pin 7-Pin 2. For coil 4, check Pin 5-Pin 2. Aim for approximately 0.4-0.8 ohms. Replace the coil assembly if it falls outside this range.