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BENDIX REX-I: Federal

  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 disconnected spark plug wire and ground spark plug. Crank engine and monitor spark.
  2. Strong Blue/White spark indicates engine or fuel system malfunction. If no or 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 or weak spark is present, 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 previous steps do not show defective components, go 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 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 be zero volts. If voltage is not present at control unit or is 12 volts with button pushed, measure voltage at diagnostic unit connector.
    Fig 1: Identifying Diagnostic Unit Components
    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 indicate 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 No. 14 (Black wire). Continuity should exist.
  11. Measure resistance between ground and ignition ECU connector terminal No. 2 (Red/Black wire). See ENGINE COOLANT TEMPERATURE SENSOR RESISTANCE table. If reading is not correct, test sensor directly to determine if fault is in sensor or wiring.
    ENGINE COOLANT TEMPERATURE SENSOR RESISTANCE

    Temperature °F (°C) Ohms
    -22 (-30) 30,000
    -4 (-20) 15,000-16,000
    32 (0) 5800-6000
    68 (20) 2200-2400
    104 (40) 1000-1200
    140 (60) 600
    176 (80) 340-360
    212 (100) 180-190
    248 (120) 100-120
  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 procedures in the ADJUSTMENTS article.
  13. Remove panel under right side of dash, at right side of bulkhead. Remove glove box. 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 an ECU. Reconnect fuel injection ECU connector and replace glove box and panel.
  14. Check P/M (pulse) generator by measuring resistance between ignition ECU terminals No. 10 (Red wire) and No. 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 for continuity between ignition ECU terminals No. 12 (Black wire) and No. 13 (Green wire). Continuity should exist. If continuity does not exist, remove jumper wire and check each wire for an open circuit. If wiring is okay, 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 to less than 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 or engine still malfunctions after repairs, install new ignition ECU. Recheck system as necessary. Reinstall ignition coil. Reassemble ignition ECU connector and reconnect it to ECU. Reconnect ignition coil/power stage connectors.
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