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Home >> Suzuki >> 2007 >> Swift + >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls & Fuel - 1.6L - DTC P0650 To P2A01 >> DTC P1391, P1392, or P1393 >> Circuit/System Testing
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Circuit/System Testing

  1. Ignition OFF, disconnect the harness connector of the rough road sensor.
  2. Ignition ON, verify that the rough road sensor parameter is less than 0.1 volt.
    • If greater than 0.1 volt, test the signal circuit of the rough road sensor for a short to voltage. If the circuit/connections test normal, replace the ECM.
  3. Ignition ON, test for less than 0.2 volt between the low reference circuit and ground.
    • If greater than 0.2 volt, test the low reference circuit for a short to voltage. If the circuit/connections test normal, replace the ECM.
  4. Ignition OFF, test for less than 5 ohms of resistance between the low reference circuit and ground.
    • If greater than 5 ohms, test the low reference circuit for an open/high resistance. If the circuit/connections test normal, replace the ECM.
  5. Ignition ON, test for 4.8-5.2 volts between the 5-volt reference circuit and ground.
      IMPORTANT: The 5-volt reference circuits are internally and externally connected at the ECM. Other component DTCs may be set. If other DTCs are set, review the electrical schematic and diagnose the applicable circuits and components.
    • If less than 4.8 volts, test the 5-volt reference circuit for a short to ground or open/high resistance. If the circuit/connections test normal, replace the ECM.
    • If greater than 5.2 volts, test the 5-volt reference circuit for a short to voltage. If the circuit/connections test normal, replace the ECM.
  6. Ignition ON, install a 3A fused jumper wire between the signal circuit and the 5-volt reference circuit. Verify that the rough road sensor parameter is greater than 4.8 volts.
    • If less than 4.8 volts, test the signal circuit for a short to ground or an open/high resistance. If the circuit/connections test normal, replace the ECM.
  7. If all circuits/connections test normal, replace the rough road sensor.
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