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Home >> Suzuki >> 2008 >> XL7 Base, AWD >> Repair and Diagnosis >> Engine Performance >> Engine Control Systems >> Engine General Information And Diagnosis >> Diagnostic Information and Procedures >> DTC P0685, P0686, P0687, P0689, or P0690 >> Circuit/System Testing
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Circuit/System Testing

  1. Ignition OFF, disconnect the powertrain relay.
    NOTE: The test lamp is used to load the circuit and may not illuminate.
  2. Connect a test lamp between the B+ supply circuit to the coil side of the powertrain relay and the negative terminal of the battery.
  3. Ignition ON, test for less than 0.1 volt between the B+ voltage circuit of the powertrain relay and the positive battery terminal.
    • If greater than 0.1 volt, repair the B+ voltage circuit to the coil side of the powertrain relay for a short to ground or an open/high resistance.
      NOTE: The test lamp is used to load the circuit and may not illuminate.
  4. Connect a test lamp between the B+ voltage supply circuit to the switch side of the powertrain relay and the negative terminal of the battery.
  5. Ignition ON, test for less than 0.1 volt between the B+ voltage circuit of the powertrain relay and the positive battery terminal.
    • If greater than 0.1 volt, repair the B+ voltage circuit to the switch side of the powertrain relay for a short to ground or an open/high resistance.
  6. With the ignition OFF, connect a test lamp between the control circuit of the powertrain relay and the B+ voltage supply circuit to the coil side of the powertrain relay.
  7. Turn ON the ignition. The test lamp should turn ON when the ignition switch is cycled ON and OFF when the ignition switch is cycled OFF.
    • If the test lamp remains ON all the time, test for a short to ground on the control circuit. If the circuit/connections test normal, replace the ECM.
    • If the test lamp remains OFF all the time, test for a short to voltage or an open/high resistance on the control circuit. If circuit/connections test normal, replace the ECM.
      NOTE: The ignition voltage circuit is between the powertrain relay and the ECM. The ignition voltage is a feedback circuit.
  8. Connect a 15A fused jumper wire between the B+ supply voltage circuit and the ignition voltage circuit of the powertrain relay.
  9. Attempt to start the engine. The engine should start.
    • If the engine does not start, test the ignition voltage circuit between the powertrain relay and the ECM for a short to ground or for an open/high resistance. If the circuit/connections test normal, replace the ECM.
  10. Ignition ON, test for less than 1 volt on the ignition voltage circuit between the powertrain relay terminal in the UBEC and ground.
    • If greater than the specified value, repair the short to voltage in the ignition voltage circuit.
  11. If all circuits/connections test normal, test or replace the powertrain relay.
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