P2149

DTC P2149

CIRCUIT DESCRIPTION
The common 2 injector drive circuit is a high-voltage supply (near 120 volts) which drives injectors for cylinder 2 and 3 in conjunction with the engine control module (ECM) grounding the injector control circuit. The ECM supplies battery voltage on the injector drive circuit to allow for fault detection. If the common 2 injector drive circuit supply to the cylinder 2 and 3 is open, this DTC will set.

Condition for Running the DTC
- The battery voltage is between 10-16 volts.
- The ignition switch is ON.
- The engine is running.

Condition for Setting the DTC
- The ECM detects that the common 2 fuel injector drive circuit is open during 8 engine rotations.

Action Taken When the DTC Sets
- The ECM illuminates the malfunction indicator lamp (MIL) when the diagnostic runs and fails.
- The ECM records the operating conditions at the time the diagnostic fails. The ECM stores this information in the Freeze Frame/Failure Records.
- The ECM disables cylinder 2 and 3 fuel injector operation.
- The ECM limits fuel injection quantity within 50%.
- The ECM limits fuel rail pressure within 11600 psi (80 MPa).
- The ECM closes the EGR valve and holds to close position.
- The ECM inhibits the cruise control.

Condition for Clearing the MIL/DTC
- The ECM turns OFF the MIL after 3 consecutive driving cycles when the diagnostic runs and does not fail. (12,000 lbs GVW)
- The ECM turns OFF the MIL when the diagnostic runs and does not fail. (Except 12,000 lbs GVW)
- A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
- A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic after the ECM turns OFF the MIL.
- Clear the MIL and the DTC with a scan tool.

Diagnostic Aids
If an intermittent condition is suspected, the following may cause an intermittent:
- Poor connections
- Misrouted harness
- Rubbed through wire insulation
- Broken wire inside the insulation

Check for the following conditions:
- Poor connection at the ECM: Inspect harness connectors for backed-out terminals, improper mating, broken locks, improperly formed or damaged terminals, and poor terminal to wire connection.
- Damaged harness: Inspect the wiring harness for damage. If the harness appears to be OK, observe the "DTC P2149" display on the scan tool with the engine running while moving connectors and wiring harness. A change in the display will indicate the location of the fault.

DTC P2149
Schematic Reference: Engine Controls Schematics
Connector End View Reference: Engine Controls Connector End Views or Engine Control Module (ECM) Connector End Views

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