G3500 A3 Engines Caterpillar

Probable Causes

• Low Heat Value (LHV) of the fuel

• Calibration of the oxygen sensor (if equipped)

• Calibration of the NO_X sensor (if equipped)

• Moisture condensation in the fuel

Recommended Actions

Low Heat Value (LHV) of the Fuel

Obtain an analysis of the gas in order to check the LHV and specific gravity of the fuel. Check that the value that is programmed into the Electronic Control Module (ECM) is accurate. Program the "Fuel Quality" parameter to the actual value of the LHV, if necessary.

Note: If the quality of the fuel is not consistent, obtain several analyses over a period of time. Program the "Fuel Quality" parameter to the average value of the LHV.

Calibration of the Oxygen Sensor (if equipped)

If the engine uses oxygen feedback to control emissions, the oxygen sensor may need calibration.

Calibrate the oxygen sensor. Refer to Troubleshooting, "Oxygen Sensor - Calibrate" for details.

If the oxygen sensor could not be calibrated successfully, refer to Troubleshooting, "Oxygen Sensor Buffer Supply" and Troubleshooting, "Oxygen Sensor Signal".

Calibration of the NO_X Sensor (if equipped)

If the engine uses NO_X feedback to control emissions, the NO_X sensor may need calibration.

Calibrate the NO_X sensor. Refer to Troubleshooting, "Nitrogen Oxide Sensor - Calibrate" for details.

If the oxygen sensor could not be calibrated successfully, refer to Troubleshooting, "Nitrogen Oxide Level - Test".

Moisture Condensation in the Fuel

Check the dryer for the fuel for proper operation. Repair the dryer, if necessary.