California (With RPO Code YF5, NE1, and VCL)

DTC P0238 (CALIFORNIA WITH RPO CODE YF5, NE1, and VCL)

CIRCUIT DESCRIPTION
The boost sensor responds to pressure changes in the intake manifold. This pressure is created by the turbocharger and changes with accelerator pedal position (APP) and engine speed. The engine control module (ECM) uses this information to provide engine overboost protection. The boost sensor has a 5-volt reference circuit, a low reference circuit, and a signal circuit. The ECM supplies 5 volts to the boost sensor on a 5-volt reference circuit, and provides a ground on a low reference circuit. The boost sensor provides a voltage signal to the ECM on a signal circuit relative to the pressure changes. The ECM monitors the boost sensor signal for voltage outside of the normal range. If the ECM detects a boost sensor signal voltage that is excessively high, this DTC will set.

CONDITIONS FOR RUNNING THE DTC
The ignition is ON

CONDITIONS FOR SETTING THE DTC
The boost pressure is more than 254 kPa for 2 seconds.

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 control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.
- 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.
- A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
- Clear the MIL and the DTC with a scan tool.

TEST DESCRIPTION

Steps 1-4:

Steps 5-8:

Steps 9-13:

The number below refers to the step number on the diagnostic table.
3. If you cannot duplicate the DTC, the information included in the Freeze Frame/Failure Records data can aid in locating an intermittent condition.