Removal
1. On ADP engines, the ignition coil is mounted on the right side of the firewall, at the rear of the engine compartment. On ADR, AFY, APT and APW engines, the coil is mounted on the valve cover, above the spark plugs of the third and fourth cylinders. The spark plug wires of these cylinders are integrated into the coil, the wires of the first and second cylinders are conventional. On AHL engines, the ignition coil is mounted in the center of the firewall at the rear of the engine compartment. On AEB and AJL engines, four high-voltage coils are mounted directly on the spark plugs.
2. On ADP and AHL engines, disconnect the low voltage wiring connector from the coil on the firewall, then disconnect the high voltage wire. Remove the coil from the firewall.
3. On ADR. AFY, APT and APW engines, remove the top engine cover, lift the retainer and disconnect the wiring connector. Unscrew the nut and disconnect the ground wire. Carefully pull the high-voltage wires off the spark plugs of cylinders 1 and 2, holding the tip, but not the wire itself. Unscrew the mounting nuts and remove the coil, simultaneously pulling the high-voltage wires off the spark plugs of cylinders 3 and 4 (fig. 3.3, e-g). Remove the gasket.
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4. On AEB and AJL engines, remove the top engine cover, disconnect the wiring from all four coils. Unscrew the bolt and disconnect the ground wire from the valve cover and move the wiring to the side. Unscrew the mounting bolts and carefully remove the coils from the valve cover, simultaneously disconnecting the high-voltage terminals from the spark plugs. Remove the gaskets from the coils. The high-voltage terminals can be removed from the coils.
Examination
5. On ADP and AHL engines, disconnect the low voltage wiring connector and connect an ohmmeter between the two low voltage terminals of the coil (pins 1 and 15). Check that the resistance of the primary winding matches the data given in Specifications. Now check the secondary winding resistance by connecting an ohmmeter between terminals 4 (high voltage) and 15 data given in Specifications (Fig. 3.5).
6. On ADR, AFY, APT and APW engines it is not possible to test the coil assembly, but you can test the power supply at the low voltage connector by connecting a tester between the center terminal and ground. Turn on the ignition - the voltmeter should register battery voltage.
7. On AEB and AJL engines, the best method of checking is to replace the coil with a known good one. Using another method, disconnect the wiring from the injectors one by one, identifying the faulty cylinder. Having identified the faulty cylinder, remove the spark plug from it and check it. If the spark plug is in good condition and is able to ensure normal engine operation, the suspicion falls on the coil, which should be replaced. Coils can be interchanged.
Installation
8. Installation - reverse procedure. To secure the wiring connector on ADR, AFY, APT and APW engines, press the lock.
(The original article is available on the website: AUDIMANUAL)