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Ignition Check (BOSCH EZ117K, B230FT Turbo Engine

NOTE: ECU terminal identifications are marked on the unit or connector.
  1. Ensure ground connections from ignition ECU and power stage to inlet manifold ground are okay. If ground connections are good, turn on ignition and measure voltage at ignition coil positive terminal. Voltage should be 12 volts. If voltage is not present, check for open circuit.
  2. Disconnect a spark plug wire from spark plug. Connect a test spark plug to the disconnected spark plug wire and ground spark plug. Crank engine and monitor spark.
  3. A strong Blue-White spark indicates an engine or fuel system malfunction. If no spark or a weak spark is present, reconnect spark plug wire to spark plug. Disconnect coil wire from distributor cap and install test spark plug. Crank engine and monitor spark. If no spark or weak spark is present, the coil or ignition system primary circuit is defective.
  4. If a strong Blue-White spark is present, check ignition rotor, distributor housing and spark plug wires. Replace components as necessary. If all the previous steps show no defective components, go to next step.
  5. Remove air cleaner assembly. Ensure ignition is off and disconnect power stage connector. See Figure . Remove connector dust cover. Connect multimeter negative (-) lead to ground and positive (+) lead to connector terminals No. 1 and No. 4. Measure each terminal individually. Turn ignition on and note voltage reading. Voltage should be approximately 12 volts. If voltage is not present, check for open circuit.
  6. Check ignition coil primary resistance by connecting multimeter to power stage connector pins No. 1 and No. 4. Resistance should be 0.6-0.9 ohm. If resistance is less than 0.6 ohm, check wires for short circuit.
  7. If wires are okay but resistance is still not 0.6-0.9 ohm, connect multimeter to ignition coil terminals No. 1 and No. 15. See Figure . If resistance is not 0.6-0.9 ohm, replace ignition coil. If resistance is 0.6-0.9 ohm, check continuity of wires between ignition coil and power stage connector pins No. 1 and No. 4. Repair or replace as necessary.
  8. Check ignition coil secondary resistance by connecting multimeter to coil high tension tower and coil terminal No. 1. Resistance should be 6500-9000 ohms. Replace coil if resistance is not as specified. Check continuity of power stage ground by connecting multimeter to power stage connector pin No. 2 and ground. Ohmmeter should show continuity. Repair or replace wire if continuity is not present.
  9. Check shield (ground) wire between ignition ECU and power stage. See Figure . Shield wire should be connected to power stage connector pin No. 3. Repair if necessary. Ensure power stage is receiving signal from ignition ECU. Disconnect wires from ignition coil terminal No. 1. Connect multimeter positive (+) lead to power stage connector pin No. 5 and negative (-) lead to ground.
  10. Crank starter motor and monitor voltage reading. Voltage should be about 2 volts. If voltage is as specified, install a new power stage and recheck circuit. If a very low voltage is present and/or is irregular, check wiring between ignition ECU and crankshaft position sensor. Repair or replace as necessary.
  11. Disconnect distributor connector. Measure voltage at distributor connector Red wire. Voltage should be about 11 volts. Measure voltage at distributor connector Blue wire. Voltage should be 5 volts. Turn ignition off. Check for ground at black wire. If ground does not exist, check for open circuit in lead from ignition ECU terminal No. 10 and check for faulty ignition ECU ground (terminal No. 20). Also check for faulty ignition ECU.
  12. Reconnect disconnected components. Ensure all connectors are secure and properly connected. With ignition off, remove panel from lower left dash and disconnect ignition ECU connector. Remove dust cover from connector. Ensure all ECU pin connection sleeves are at the same height.
  13. Reconnect connector with dust cover removed. Disconnect White/Red and Blue leads from ignition coil. Using voltmeter, backprobe connector at terminal No. 24 (Blue wire). Turn ignition on. Turn crankshaft by hand. Voltmeter should indicate more than 1.8 volts each time a vane passes Hall Effect sensor. Voltmeter should indicate 0-.7 volt each time an opening passes Hall Effect sensor. If voltage is incorrect, replace Hall Effect sensor.
  14. Turn ignition off and disconnect connector. Measure voltage at ignition ECU connector terminal No. 6 and ground. Turn ignition on. Voltage should be approximately 12 volts. Measure voltage between ECU connector terminals No. 6 and No. 20. Voltage should be approximately 12 volts. If voltage is not as specified, repair wiring as necessary.
  15. Turn ignition off. If no defects are found after performing all of the previous steps, or if engine still malfunctions after repairs, install a new ignition ECU. Recheck system as necessary.
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