There are three basic checks that should be performed:
- Check for active/historic codes. All causes need to be checked once the fault is identified. Record faults on the Application For Adjustment (AFA) claim, if there is to be a claim.
- Check the DDEC parameters, progressive shift settings, torque limiting values, and injector codes. Are they correct? Is proper rating applied? If vehicle is new, is it spec’d correctly?
- Check that the dyno-measured power is within Detroit Diesel specifications as Listed in Table “Minimum Acceptable Wheel HP” for minimum acceptable wheel HP data. Record data on AFA claim.
Note: Service information letter instructions published following the date of this document take precedence.
Possible causes of low power and symptoms are listed in Table “Low Power Troubleshooting Chart” .
| Possible Causes | Symptoms | ||||||
| Loss of Power | Misfires | Poor
Acceleration |
Erratic Idle | Engine Dies | Black Smoke | Excessive Oil
Consumption |
|
| Fuel Filter Restriction | X | X | X | X | X | — | — |
| Fuel Shut-Off Valve not Open | X | X | X | X | X | — | — |
| Air in the Fuel | X | X | X | X | X | — | — |
| Faulty Injector(s) | X | X | X | X | X | X | — |
| Faulty Turbocharger | X | — | X | — | — | X | X |
| EGR Valve* | X | — | X | X | — | X | — |
| Delta P Sensor or Plugged Lines* | X | — | X | X | — | X | — |
| Charge Air Cooler Leak | X | — | X | — | — | X | — |
| Intake or Exhaust Manifold Leak | X | — | X | — | — | X | — |
| Quality/Grade of Fuel | X | X | X | X | — | X | — |
| High Fuel Temperature – Above 130°F | X | — | X | — | — | — | — |
| Restricted Air Intake | X | — | X | — | — | X | — |
| Crankcase Overfilled | X | — | X | — | — | — | X |
| Faulty Fan Operation, Always On | X | — | X | — | — | — | — |
| Debris in Fuel Tank – Air Vent Plugged | X | X | X | X | X | — | — |
Table 1. Low Power Troubleshooting Chart
