Circuit Description
The flow damper comprises a piston, ball, spring seat, and spring. The flow damper is used to damp the pressure pulsating in the common rail and the injection pipe. During driving, the flow of fuel makes the piston, ball, and spring seat move a little to the injector side and float. If too much fuel passes the flow damper, the ball moves further toward the injector until the ball comes into contact with the seat surface of the flow damper unit, thereby shutting the fuel passages. If the ECM must adjust the fuel flow for a specific cylinder an excessive amount, the appropriate DTC will set.
Conditions for Running
| • | DTCs P0201-P0206, P0704, P1263, P1264, P1265, P1266, U2104, U2106 are not set. |
| • | The coolant temperature is more than 60°C (140°F). |
Conditions for Setting the DTC
Correction of uneven injection amounts exceeding 4 mm³/stroke and these continue for 255 times.
Action Taken When the DTC Sets
| • | The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails. |
| • | The ECM limits fuel delivery. |
Conditions for Clearing the MIL/DTC
| • | The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail. |
| • | A current DTC, Last Test Failed, clears when the diagnostic runs and passes. |
| • | Clear the MIL and the DTC with a scan tool. |
Diagnostic Aids
Inspect for the following conditions:
| • | Poor connections at the ECM |
| Inspect the harness connectors for baked-out terminals, improper mating, broken locks, improperly formed or damaged terminals, and poor terminal-to-wire connections. |
| • | Inspect the fuel filter for a restriction. |
Step | Action | Yes | No |
|---|---|---|---|
Schematic Reference: Engine Controls Schematics | |||
1 | Is the DTC set with the ignition ON or with the engine operating? | Go to Step 2 | Go to Intermittent Conditions |
2 |
Are any DTCs displayed? | Go to Step 4 | Go to Step 3 |
3 |
Did you complete the action? | Go to Step 9 | -- |
4 | Remove the flow damper from the common rail according to diagnostic code. Does the flow damper remain open? | Go to Step 7 | Go to Step 5 |
5 |
Did you complete the action? | Go to Step 9 | Go to Step 6 |
6 |
Did you complete the action? | Go to Step 9 | Go to Step 8 |
7 | Replace the flow damper. Did you complete the replacement? | Go to Step 8 | -- |
8 | Do you have a similar problem as in Step 3? | Go to Step 3 | Go to Step 9 |
9 | Start the engine. Are any DTCs set? | System OK | |
