lemon-mirror:
Home >> Volvo >> 1990 >> 760 GLE, AW71L >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Basic Testing >> Ignition System >> Ignition Check (BENDIX REX 1, B230F Engine, Federal)

Ignition Check (BENDIX REX 1, B230F Engine, Federal)

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, disconnect a spark plug wire from spark plug. Attach a test spark plug to the disconnected spark plug wire and ground spark plug. Crank engine and monitor spark.
  2. 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.
  3. 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, proceed to next step.
  4. Turn ignition off. Reconnect disconnected components. Ensure all connectors are secure and properly connected. With ignition off, remove panel from lower left dashboard and disconnect ignition ECU connector. Remove dust cover from connector. Ensure all pin connection sleeves are at the same height.
  5. Measure voltage at ignition ECU connector terminal No. 5. Voltage reading should be about 12 volts. If voltage is not present, check circuit between ignition ECU and fuse holder.
  6. Turn ignition on. Open diagnostic connector at left rear of engine compartment and connect test lead to socket No. 6 (marked on unit). See Fig 1 . Measure voltage at ignition ECU connector terminal No. 1. Voltage should be about 12 volts. Press test button on diagnostic unit. Voltage should now read zero volt. If voltage is not present at control unit or if voltmeter reads 12 volts with button pushed, measure voltage at diagnostic unit connector.
    Fig 1: Diagnostic Unit
    G90H17332Courtesy of VOLVO CARS OF NORTH AMERICA.
  7. Measure voltage at diagnostic unit connector Blue lead. Voltage should be about 12 volts. Using ohmmeter, check continuity between diagnostic unit connector Black lead and ground. Ensure continuity exists.
  8. Turn ignition off. Check continuity between diagnostic unit test lead and pin No. 8 (under function selector button). Ohmmeter should read infinity. Press test button on diagnostic unit. Continuity should now be present.
  9. Using ohmmeter, test for continuity of diagnostic unit LED. Connect ohmmeter leads to pin under LED and to test lead. Continuity should exist in only one direction.
  10. Turn ignition on. Measure voltage at ignition ECU terminal No. 6 (Blue wire). Voltage should be about 12 volts. Turn ignition off. Using ohmmeter, check continuity between ignition ECU connector terminals No. 20 (Brown wire) and 14 (Black wire). Continuity should exist.
  11. Measure resistance between ignition ECU connector terminal No. 2 (Red/Black wire) and ground. Ohmmeter reading should be as shown in COOLANT TEMPERATURE SENSOR RESISTANCE  table. If reading is not correct, test sensor directly to determine if fault is in sensor or wiring.
    COOLANT TEMPERATURE SENSOR RESISTANCE

    Temperature °F (°C) Ohms
    -4 (-20) 15,000-16,000
    32 (0) 5800-6000
    68 (20) 2200-2400
    104 (40) 1000-1200
    140 (60) 500-600
    176 (80) 340-360
    212 (100) 180-190
  12. Check continuity between ignition ECU connector terminal No. 7 (Orange wire) and ground. Ensure continuity exists. Depress accelerator until throttle switch opens slightly. Ohmmeter reading should increase to infinity. If reading is not correct, measure throttle switch resistance directly to determine if fault is in switch or wiring. Adjust throttle switch if necessary. See ADJUSTMENTS article.
  13. Remove panel under right side of dash, at right side of bulkhead. Remove glove compartment. Turn ignition off. Disconnect fuel injection ECU connector. Check for continuity between ignition ECU terminal No. 8 (Yellow wire) and fuel injection ECU terminal No. 25 (Yellow wire). If continuity is not present, check connectors and wiring. Repair as necessary. If continuity is still not present, internal fault is present in one of the ECUs. Reconnect fuel injection ECU connector and replace glove compartment and panel.
  14. Check P/M (pulse) generator by measuring resistance between ignition ECU terminals No. 10 (Red wire) and 23 (Blue wire). Resistance should be 215-265 ohms. Ensure shield is connected to ECU terminal No. 11.
  15. Disconnect knock sensor connector and place a jumper wire between terminals. Check continuity between ignition ECU terminals No. 12 (Black wire) and 13 (Green wire). Ohmmeter should show continuity. Ensure resistance to ground is infinity. If resistance is too high (infinity), remove jumper wire and test each wiring lead. If leads are intact, replace knock sensor.
  16. Reconnect knock sensor connector. Reassemble and reconnect ignition ECU connector.
  17. Disconnect connectors from ignition coil and power stage. Remove mounting screws and lift ignition coil from power stage. Measure resistance across low tension side of ignition coil. Resistance should be about .5 ohm.
  18. Measure resistance between high tension terminal and each low tension terminal. Resistance should be about 5000 ohms. If resistance is not as specified, replace ignition coil.
  19. Turn ignition on. Check for battery voltage at Blue wire of 3-pin power stage connector. If voltage is low or does not exist, check power supply lead connections at ignition ECU and ignition coil/power stage. Ensure voltage does not drop below 10.5 volts while engine is cranking. Turn ignition off.
  20. Ensure ground is present at Brown/Black wire of 3-pin power stage connector and at Black wire of 2-pin power stage connector. Using a self-powered test light or buzzer, check for continuity between Orange wire of 2-pin power stage connector and ignition ECU terminal No. 16.
  21. 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. Reinstall ignition coil. Reassemble ignition ECU connector and reconnect to ECU. Reconnect ignition coil/power stage connectors.
· About lemon-mirror