The manifold absolute pressure (MAP) sensor measures the pressure inside the intake manifold. Pressure in the intake manifold is affected by turbocharger output, engine speed, accelerator pedal input, ambient air temperature, and barometric pressure (BARO). A diaphragm within the MAP pressure sensor is displaced by the pressure changes that occur from the varying load and operating conditions of the engine. The sensor translates these changes into electrical resistance. The engine control module (ECM) supplies a regulated 5 volts on the 5-volt reference circuit and a ground on a low reference circuit. The MAP sensor provides a signal voltage to the ECM, relative to boost pressures, on the MAP sensor signal circuit. The ECM converts the signal voltage input to a pressure value. Under normal operation, the lowest pressure that can exist in the intake manifold is equal to the BARO. This occurs when the vehicle is operated at idle or when the ignition is ON while the engine is OFF. The highest manifold pressures occur when the turbocharger output is high. Manifold pressure can range from 58 kPa (8 psi) when pressures are low to more than 295 kPa (42.7 psi) when pressures are high, depending on the BARO. The MAP pressure sensor has a range of 43-365 kPa (6-53 psi). The ECM diagnoses boost pressures by a calculated predicted value at a predetermined engine load and speed. The ECM then compares the predicted value to the sensor actual input.

The ECM detects that the measured boost pressure is greater than 39 kPa above the expected range for 10 seconds.

DTC P0234 is a Type A DTC.

DTC P0234 is a Type A DTC.

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Turbocharger System Description

Electrical Information Reference

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

1. Verify that the following DTCs are not set, P0106, P0107, P0108, or P2563.

⇒	If any of the DTCs are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle.

2. Engine running at idle; observe the scan tool MAP and BARO parameters. The reading should be within 1-10 kPa of each other.
3. Operate the vehicle within the Conditions for Running the DTC to verify that the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

1. Verify the integrity of the air induction system and the turbocharger system by inspecting for restrictions or leaks.
2. Engine running, command the TC Vane Pos. Ctrl. Solenoid ON, while performing a snapshot of the induction data list. Perform the following actions during the snapshot: Refer to Scan Tool Snapshot Procedure.

2.1.	Slowly increase the engine speed to 1,700 RPM for 5 seconds, and then slowly return the engine speed to a stable idle.

2.2.	Plot the snapshot and verify that the MAP sensor parameter increases smoothly and follows the Engine Speed parameter through-out the entire engine speed range.

⇒	If the MAP parameter did not change smoothly or did not follow the Engine Speed parameter, inspect the turbocharger and turbocharger ducts for debris, damage, or sticking vanes. Refer to Turbocharger Cleaning and Inspection.

3. If the turbocharger inspections are normal, replace the MAP sensor.

1. Install any components or connectors that have been removed or replaced during diagnosis.
2. Perform any adjustment, programming, or setup procedures that are required when a component or module is removed or replaced.
3. Clear the DTCs.
4. Turn OFF the ignition for 90 seconds.
5. Duplicate the Conditions for Running the DTC and use the Freeze Frame/Failure Records, if applicable, in order to verify the DTC does not reset. If the DTC resets or another DTC is present, refer to Diagnostic Trouble Code (DTC) List - Vehicle and perform the appropriate diagnostic procedure.
6. Engine running, observe the scan tool Soot Mass parameter. The value should be less than 30 grams.

⇒	If the Soot Mass value is greater than 30 grams, perform the Diesel Particulate Filter (DPF) Regeneration Enable.