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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 P0121, P0122, P0123, P0221, P0222, or P0223 >> Circuit/System Testing
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Circuit/System Testing

  1. Ignition OFF, remove the fuse that supplies B+ to terminal X2-56 of the ECM.
  2. Disconnect the throttle body harness connector.
    NOTE: The control module or the sensor may be damaged if the circuit is shorted to battery positive voltage.
  3. Ignition OFF, test for 5 ohms between the low reference circuit terminal C and ground.
    • If greater than the specified range, test the low reference circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the ECM.
  4. Install the fuse that supplies B+ to terminal X2-56 of the ECM.
  5. Ignition ON, load test for 4.8-5.2 volts between the 5-volt reference circuit terminal E and ground.
    NOTE: 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 the specified range, test the 5-volt reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the ECM.
    • If greater than the specified range, test the 5-volt reference circuit for a short to voltage. If the circuit tests normal, replace the ECM.
  6. Ignition ON, verify that the scan tool TP sensor 1 voltage parameter is less than 0.3 volt.
    • If greater than the specified value, test the signal circuit for a short to voltage. If the circuit tests normal, replace the ECM.
  7. Connect a 3A fused jumper wire between the 5-volt reference circuit terminal E and the TP sensor 1 signal circuit terminal D. Verify the scan tool TP sensor 1 voltage parameter is greater than 4.89 volts.
    • If less than the specified value, test the signal circuit for an open/high resistance or for a short to ground. If the circuit tests normal, replace the ECM.
  8. Verify the scan tool TP sensor 2 voltage parameter is greater than 4.97 volts.
    • If less than the specified value, test the signal circuit for a short to ground. If the circuit tests normal, replace the ECM.
      NOTE: If the fuse in the jumper wire opens, the signal circuit is shorted to a voltage.
  9. Connect a 3A fused jumper wire between the TP sensor 2 signal circuit terminal F and the low reference circuit terminal C. Verify the scan tool TP sensor 2 voltage parameter is less than 0.10 volt.
    • If greater than the specified value, test the signal circuit for an open/high resistance or for a short to voltage. If the circuit tests normal, replace the ECM.
  10. If all circuits test normal, replace the throttle body assembly.
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