Ignition Coil Check
Required Special Tools:
- MB992744: Vehicle communication interface-Lite (V.C.I.-Lite)
- MB992745: V.C.I.-Lite main harness A
- MB992747: V.C.I.-Lite USB cable short
- MB992748: V.C.I.-Lite USB cable long
- MB991958: Scan Tool (M.U.T.-III Sub Assembly)
- MB991824: Vehicles Communication Interface (V.C.I.)
- MB991827: M.U.T.-III USB Cable
- MB991910: M.U.T.-III Main Harness A (Vehicles with CAN communication system)
NOTE:
It is impossible to carry out an easy check using a circuit tester because a diode and so on are integrated into the inside circuit of this ignition coil. Accordingly, check the ignition coil in the following procedure.
CAUTION:
To prevent damage to scan tool (M.U.T.-III), always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool (M.U.T.-III).
- Turn the ignition switch to the "LOCK" (OFF) position and then connect scan tool (M.U.T.-III) to the data link connector (Refer to DIAGNOSTIC FUNCTION ).
- Make sure the diagnostic trouble codes (DTCs) are not set using scan tool (M.U.T.-III). If set, record the DTCs. Carry out the troubleshooting for the set DTCs and solve the problems even if not related to the ignition.
- Disconnect the injector connectors on all of the cylinders.
- Disconnect the ignition coil connector.
- Remove the ignition coil and install a good spark plug to the ignition coil.
- Connect the ignition coil connector.
- Ground the side electrode of the spark plug and crank the engine.
- Check that spark is produced between the electrodes of the spark plug.
- If the spark plug has weak sparks or no sparks, carry out the same check using a good ignition coil. If there are strong sparks on this check with a good ignition coil, it becomes clear there is a problem with the ignition coil. Replace the ignition coil with a new one. If there are no sparks on this check with a good ignition coil, there is probably a problem with the ignition circuit. Check the ignition circuit.
- Using scan tool (M.U.T.-III), make sure whether the DTCs are stored due to the check, or not. Except the DTCs stored in Step 2, clear the DTCs all together if they are present. And then, carry out the troubleshooting about the DTCs recorded.
- Turn the ignition switch to the "LOCK" (OFF) position, and then disconnect the scan tool (M.U.T.-III).