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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 P2122, P2123, P2127, P2128, or P2138 >> 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 harness connector at the accelerator pedal assembly.
  3. Test for less than 5 ohms between the appropriate low reference circuit of the APP sensor and ground.
    • If greater than 5 ohms, test the low reference circuit of the APP sensor for a short to voltage, or an open/high resistance. If the circuit/connections test normal, replace the ECM.
  4. Install the fuse that supplies B+ to terminal X2-56 of the ECM.
    NOTE: The 5-volt reference circuit voltage can be within the specified range with a high resistance in the circuit. If this condition is suspected, refer to DIAGNOSTIC AIDS .
  5. Ignition ON, test for 4.8-5.2 volts between the appropriate 5-volt reference circuit of the APP sensor and ground.
    • If less than the specified value, 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 the specified value, test the 5-volt reference circuit for a short to voltage. If the circuit/connections test normal, replace the ECM.
  6. Observe the appropriate scan tool APP sensor voltage parameter. Verify the voltage is less than 0.3 volt.
    • If greater than the specified value, test the signal circuit of the applicable APP sensor for a short to voltage. If the circuit/connections test normal, replace the ECM.
  7. Install a 3A fused jumper wire between the appropriate signal circuit and the 5-volt reference circuit of the APP sensor. Verify the scan tool APP sensor voltage parameter is greater than 4.8 volts.
    • If less than the specified value, test the appropriate signal circuit for a short to ground or an open/high resistance. If the circuit/connections test normal, replace the ECM.
    • If both APP sensor voltage parameters display greater than 4.8 volts test the signal circuits of the APP sensors for a shorted together condition. If the circuit/connections test normal, replace the ECM.
  8. If all circuits/connections test normal, test or replace the accelerator pedal assembly.