B5.9G, B5.9LPG, B Gas Plus, B LPG Plus, and B Gas International Engines – Engine Power Output Low

Fuel level is low in the tank

Fill the supply tank. Refer to the OEM service manual.

Electronic fault codes are active

For instructions on how to read active fault codes, refer to Procedure (Electronic Controlled Fuel System) in Section 1. If fault codes are active, contact a Cummins Authorized Repair Facility.

Accelerator pedal or lever position sensor or circuit is malfunctioning

Check for foot pedal restriction. Check the accelerator pedal or lever position sensor and circuit. Refer to the OEM service manual.

Engine is operating above recommended altitude

Engine power decreases above recommended altitude. Refer to the engine data sheet for specifications.

Fuel leak

Check the fuel lines, fuel connections, and fuel filters for leaks using the combustible gas detector service tool. Refer to a Cummins Authorized Repair Facility.

Load is excessive for engine horsepower rating

Reduce the load on the engine. Refer to the engine data sheet for specifications.

Ignition coil malfunctioning

Check the ignition coil. Refer to Procedure 013-012 (Ignition Coil) in Section 6.

Spark plug(s) damaged or incorrect gap

Inspect plug(s). Refer to Procedure 013-016 (Spark Plugs) in Section 6.

Battery voltage is low or bad ground connection at battery

Check the batteries. Check the battery circuit. The battery cable ground must measure within OEM specifications for voltage drop under electrical load. Refer to the OEM service manual.

Oil from the fuel has accumulated on the gas mass flow sensor, screen packs, or elsewhere in the fuel system

Check for oil in the fuel system. Refer to a Cummins Authorized Repair Facility.

Air intake or exhaust leaks

Check for loose or damaged piping connections and missing pipe plugs. Check the turbocharger and exhaust manifold mounting. Refer to Procedure 010-058 (Air Intake Piping) in Section 3 or a Cummins Authorized Repair Facility.

Charge air cooler fins, radiator fins, or air conditioner condenser fins are damaged or obstructed with debris

Inspect the charge air cooler, air conditioner condenser, and radiator fins. Clean, if necessary. Refer to Procedure 010-027 (Charge-Air Cooler) in Section 5.

Air intake system restriction

Check the air intake system for restriction. Refer to Procedure 010-059 (Air Cleaner Restriction) in Section 4.

Fuel grade is not correct for the application or the fuel quality is poor

Operate the engine from a tank of high-quality fuel. Refer to Procedure 018-002 (Fuel Recommendations and Specifications) in Section V.

Overhead adjustments are not correct

Measure and adjust the overhead settings. Refer to Procedure 003-004 (Overhead Set) in Section 6.

Automatic transmission shift points are not set correctly

Verify that shift points are set at approximately 200 rpm below rated speed. Contact the transmission manufacturer.

Speedometer is malfunctioning or the road speed is excessive

Calibrate the speedometer. Refer to the OEM service manual.

Lubricating oil level is above or below specification

Check the oil level. Add or drain oil, if necessary. Refer to Procedure 007-043 (Lubricating Oil Level) in Section 3.