VIN L
DTC P0299
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (Diagnostic System Check - Vehicle) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Strategy Based Diagnosis) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Diagnostic Procedure Instructions) provide an overview of each diagnostic category.
DTC Descriptor
DTC P0299
- Turbocharger Engine Underboost
Circuit/System Description
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 intake manifold 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 throttle is not being used while 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 monitors the MAP sensor by comparing a calculated predicted value at a predetermined engine load and speed, to the actual sensor input.
Conditions for Running the DTC
* DTC P0045, P0047, P0048, P006E, P006F, P007C, P007D, P0102, P0103, P0107, P0108, P0117, P0118, P02E0, P02E8, P02E9, P02EB, P0403, P122D, P140F, P2228, P2229, P2453, P2494, P2495, P2564, P2565, or P268A is not set.
* The engine speed is stable between 1400-3000 RPM.
* Fuel injector delivery rate is stable.
* Ambient air temperature is greater than -7°C (19.4°F).
* BARO is greater than 75 kPa (11 psi).
* Turbocharger actuator position sensor offset learning is not active.
* Turbocharger vane cleaning, wiping, procedure is not active.
* DTC P0299 runs continuously when the above conditions are met.
Conditions for Setting the DTC
The ECM detects that the calculated difference between the desired and actual boost pressure is greater than a calibrated threshold for 10 s.
Action Taken When the DTC Sets
DTC P0299 is a Type B DTC.
Conditions for Clearing the DTC
DTC P0299 is a Type B DTC.
Reference Information
Schematic Reference
Engine Controls Schematics ([1][2]Electrical Diagrams)
Connector End View Reference
Component Connector End Views (Connector End Views By Name)
Description and Operation
Turbocharger System Description (Description and Operation)
Electrical Information Reference
* Circuit Testing (Circuit Testing)
* Connector Repairs (Connector Repairs)
* Testing for Intermittent Conditions and Poor Connections (Testing for Intermittent Conditions and Poor Connections)
* Wiring Repairs (Wiring Repairs)
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions (Powertrain Diagnostic Trouble Code (DTC) Type Definitions)
Scan Tool Reference
Control Module References (Programming and Relearning) for scan tool information
Circuit/System Verification
1. Verify that DTC P0106, P2598 or P2599 is not set.
• If a DTC is set, refer to Diagnostic Trouble Code (DTC) List - Vehicle (Diagnostic Trouble Code (DTC) List - Vehicle).
2. Ignition ON, Engine OFF, observe the scan tool BARO and MAP Sensor parameters. The parameters should be within 15 kPa (2.2 psi).
3. Engine running, command the TC Vane Pos. Ctrl. Solenoid ON with a scan tool, while performing a snapshot of the induction data list. Refer to Scan Tool Snapshot Procedure (Scan Tool Snapshot Procedure). Perform the following actions during the snapshot:
1. Slowly increase the engine speed to 1,700 RPM for 5 s and then slowly return the engine speed to a stable idle.
2. Plot the MAP sensor parameter vs engine speed. The MAP sensor parameter should increase and decrease smoothly and follow the Engine Speed parameter throughout the entire engine speed range.
4. 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.
Circuit/System Testing
Note: Perform the Repair Verification after completing the Circuit/System Testing.
1. Verify the integrity of the air induction system and the turbocharger system by inspecting for the following conditions:
* Any damaged components
* Any loose or improperly installed components
* A wet or restricted air filter
* Any exhaust leaks before the turbocharger
* Any exhaust restrictions after the turbocharger
* Any snow or ice build-up in cold climates at the air cleaner and MAF sensor
* Any water, snow, ice build-up, restrictions or coking at the MAP sensor
• If a condition is found, repair or replace the affected component as necessary.
2. Test the charge air cooler for leaks. Refer to Charge Air Cooler Diagnosis (Induction System Smoke Test) (Charge Air Cooler Diagnosis (Induction System Smoke Test)) Charge Air Cooler Diagnosis (Charge Air Cooler Air Leak Test) (Charge Air Cooler Diagnosis (Charge Air Cooler Air Leak Test)) Charge Air Cooler Diagnosis (Full System Air Leak Test) (Charge Air Cooler Diagnosis (Full System Air Leak Test)).
3. Inspect the turbocharger oil supply tube for restrictions.
• If a restriction is found, clean or replace the oil supply tube as necessary.
4. Inspect the turbocharger and turbocharger ducts for debris, sticking vanes, worn impeller and turbine blades or damage. Refer to Turbocharger Cleaning and Inspection (VIN L).
• If worn or damaged turbocharger blades or vanes are found, replace the turbocharger assembly.
5. If the induction system, charge air cooler system, the turbocharger and the turbocharger oil supply test normal, replace the B74 MAP sensor.
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.
* Manifold Absolute Pressure Sensor Replacement (Service and Repair)
* Turbocharger Replacement (Turbocharger Replacement)
* Turbocharger Oil Feed Pipe Replacement (Turbocharger Oil Feed Pipe Replacement)
* Control Module References (Programming and Relearning) for ECM replacement, setup, and programming