P3449

DTC P3449

SYSTEM DESCRIPTION
The valve lifter oil manifold (VLOM) solenoid for cylinder #7 is connected to a fused ignition 1 voltage circuit supplied by the powertrain relay in the underhood fuse block. The ground or control circuit for the solenoid is connected to a low-side driver internal to the engine control module (ECM). Each low-side driver has its own fault detection circuit, which monitors the solenoid control circuit for an incorrect voltage level. If an incorrect voltage level, such as an open, high resistance, short to ground, or a short to battery positive voltage is detected, the low-side driver will turn OFF and the fault detection circuit will communicate the condition to the central processor internal to the ECM. This DTC will set when the ECM detects an incorrect voltage level on the ignition 1 voltage circuit to the solenoid, or the solenoid control circuit, after the ignition switch is turned ON. This DTC could also set if an incorrect voltage level is detected when the ignition switch is turned OFF before the ECM powers down.

DTC DESCRIPTOR
This diagnostic procedure supports the following DTC:
DTC P3449 Cylinder 7 Deactivation Solenoid Control Circuit

CONDITIONS FOR RUNNING THE DTC
- The engine speed is greater than 400 RPM.
- The ignition voltage is greater than 10 volts, but less than 18 volts.
- DTC P3449 runs continuously when the above conditions are met.

CONDITIONS FOR SETTING THE DTC
- The ECM detects that the command state of the low-side driver and the actual voltage level of the control circuit do not match.
- The condition exists for more than 5 seconds.

ACTION TAKEN WHEN THE DTC SETS
- The control module stores the DTC information into memory when the diagnostic runs and fails.
- The malfunction indicator lamp (MIL) will illuminate.
- The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Failure Records.
- The driver information center, if equipped, may display a message.

CONDITIONS FOR CLEARING THE MIL/DTC
- 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 non-emission related diagnostic.
- Clear the DTC with a scan tool.

DIAGNOSTIC AIDS
This diagnostic table assumes that the vehicle battery is fully charged. Refer to Battery Inspection/Test (Non-HP2) in Starting and Charging. Component Tests and General Diagnostics

TEST DESCRIPTION

Steps 1 - 8:

Steps 9 - 15:

Steps 16 - 22:

Steps 23 - 37:

Steps 28 - 36:

Steps 37 - 43:

The numbers below refer to the step numbers on the diagnostic table.
3. This step tests for a short to battery positive voltage on the ignition 1 voltage circuit or the solenoid control circuit.
4. This step tests for an open circuit to the ENG 1 fuse.
5. The question in this step is based on the testing that took place in step 4.
9. This step performs a functional test of the VLOM assembly.
25. This step tests cylinder #7 VLOM solenoid for a short to ground condition.