Symptom Tree
|
Electronic fault codes are active |
For instructions on how to read active fault codes, refer to Procedure 101-007 (Electronic Controlled Fuel System) in Section 1. If fault codes are active, contact a Cummins Authorized Repair Facility. |
 |
|
Fuel consumption and/or oil consumption data are inaccurate |
Verify fuel consumption and/or oil consumption data. Refer to the engine data specifications. |
|
|
Vehicle is not being fueled completely |
Verify all fuel tank supply valves are open and the tanks contain fuel. |
|
|
Vehicle has changed routes or loads |
Consider operating environment and its effect on fuel economy. Adverse weather, strong head winds, variable routes, and heavier loads can increase fuel consumption. |
|
|
Operator technique is not correct |
Explain correct engine operation to the operator. Refer to Procedure 101-999 (Operating Instructions — Overview) in Section 1. |
|
|
Fuel consumption is changing due to seasonal or operational changes |
Review fuel consumption records for the past 3 to 6 months to determine the effects of seasonal or operational changes. |
|
|
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. |
|
|
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. |
|
|
Drivetrain is not correctly matched to the engine |
Check for correct gearing and drivetrain components. Refer to the OEM vehicle specifications. |
|
|
Coolant temperature is below specification |
Refer to the Coolant Temperature is Below Normal symptom tree. |
|
|
Lubricating oil level is above specification |
Check the oil level. Verify the dipstick calibration and oil pan capacity. Fill the system to the specified level. Refer to the OEM service manual. |
|
|
Wheel alignment is not correct (tractor or trailer) |
Check the wheel alignment. Refer to the OEM service manual and the manufacturer’s instructions. |
|
|
Hubometer or odometer is miscalibrated |
Check the hubometer and odometer calibrations. Calibrate or replace the hubometer or odometer, if necessary. Calculate fuel consumption with new mileage figures. |
|
|
Speedometer is malfunctioning or the road speed is excessive |
Calibrate the speedometer. Refer to the OEM service manual. |
|
|
Ignition coil malfunctioning |
Check the ignition coil. Refer to Procedure 013-012 (Ignition Coils) in Section 6 . |
|
|
Spark plug(s) damaged or incorrect gap |
Inspect plug(s). Refer to Procedure 013-016 (Spark Plugs (Standard)) 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. |
|
|
Exhaust system restriction is above specification |
Check the exhaust system for restrictions. Refer to the OEM service manual. |
|
|
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 is restricted or leaking |
Inspect the charge air cooler for air restrictions or leaks. Refer to Procedure 010-027 (Charge-Air Cooler) in Section 5. |
|
|
Air filter is restricted |
Check the air filter for restrictions. Refer to Procedure 010-059 (Air Cleaner Restriction) in Section 4. |
|
|
Overhead adjustments are not correct |
Measure and adjust the overhead settings. Refer to Procedure 003-004 (Overhead Set) in Section 6. |
|
| Contact a Cummins Authorized Repair Facility |
