DTC P0234 or P0299

Engine Controls and Fuel - 3.0L LM2 Diesel | Diagnostic Information and Procedures | Document ID: 5652048 Diagnostic Instructions Perform the Diagnostic System Check prior to using this diagnostic procedure: Diagnostic System Check - Vehicle Review the description of Strategy Based Diagnosis: Strategy Based Diagnosis An overview of each diagnostic category can be found here: Diagnostic Procedure Instructions DTC Descriptor DTC P0234 Engine Overboost DTC P0299 Engine Underboost Circuit/System Description For an overview of the component/system, refer to: Compressor Air Intake Turbocharger System Description

Circuit	Description
Control — Terminal 1	The output circuit is switched from ground to 12 V to activate the component. The output is PWM controlled.
Control — Terminal 5	The output circuit is switched from ground to 12 V to activate the component. The output is PWM controlled.

	Component	Description
	K20 Engine Control Module	The control module contains a microprocessor used to process input data to control outputs. The control module controls a series of actuators to ensure optimal engine performance. The control module does this by reading values from a variety of sensors, interprets the data and adjusts the engine actuators accordingly.
	M103 Turbocharger Vane Position Actuator	The assembly has several functions: The valve is actuated by a 12 V DC motor. A spring is used to keep the valve in the open position. The valve actuator motor moves the valve in the closed direction. The more current flows through the motor, the more the valve closes. The component M103 contains a contactless inductive position sensor. A fixed transmitter

Component	Description
	coil excites a movable rotor, which in turn induces a current in a fixed receiver coil. The current varies with the angle of the rotor. Electronics inside the sensor convert the current into digital data which is transmitted via a serial data circuit to the control module K20.

Conditions for Running the DTC P0234 DTC P003A, P0045–P0048, P0071–P0074, P00C7, P0106–P0108, P0116–P0119, P0128, P02E1, P02E8, P02E9, P111E, P122D, P169E, P169F, P16FA, P16FC, P2227–P2230, U0654, U0656 = Not set Ambient Air Temperature = −20 to 55°C (−4 to 131°F) Barometric Pressure Sensor = 70 to 110 kPa (10.1 to 15.9 PSI) Desired Boost Pressure = 122 to 220 kPa (17.6 to 31.9 PSI) Engine Coolant Temperature = 60 to 130°C (140 to 266°F) Engine Speed = 2,500 to 4,000 RPM Ignition and Start Signal = Greater than 11 V Intake Air Flow Valve Position = Greater than 84% — Commanded Off Intake Air Flow Valve Position = Greater than 74% — Commanded On Turbocharger Boost Control Command = Stable Frequency the DTC runs = Continuously — After the running conditions are met — For greater than 1 s P0299 DTC P003A, P0045–P0048, P0071–P0074, P00C7, P0106–P0108, P0116–P0119, P0128, P02E1, P02E8, P02E9, P111E, P122D, P169E, P169F, P16FA, P16FC, P2227–P2230, U0654, U0656 = Not set Ambient Air Temperature = −22 to 55°C (−7.6 to 131°F) Barometric Pressure Sensor = 70 to 110 kPa (10.1 to 15.9 PSI) Desired Boost Pressure = 80 to 180 kPa (11.6 to 26.1 PSI) Engine Coolant Temperature = 60 to 130°C (140 to 266°F) Engine Speed = 1,300 to 2,050 RPM Ignition and Start Signal = Greater than 11 V Intake Air Flow Valve Position = Greater than 84% — Commanded Off Intake Air Flow Valve Position = Greater than 74% — Commanded On Turbocharger Boost Control Command = Stable Frequency the DTC runs = Continuously — After the running conditions are met — For greater than 1 s Conditions for Setting the DTC Boost Pressure = Actual pressure is not equal to the desired pressure — For greater than 10 s Action Taken When the DTC Sets DTCs listed in the DTC Descriptor category = Type B DTC Warning Message = Engine Power Is¦Reduced / Service Emission System Reduced Engine Power = Active Conditions for Clearing the DTC DTCs listed in the DTC Descriptor category = Type B DTC Reference Information Schematic Reference Engine Controls Schematics Connector End View Reference Master Electrical Component List Electrical Information Reference Circuit Testing Connector Repairs Testing for Intermittent Conditions and Poor Connections Wiring Repairs DTC Type Reference Powertrain Diagnostic Trouble Code (DTC) Type Definitions Scan Tool Reference Control Module References Circuit/System Verification

1. Ignition » On / Vehicle » In Service Mode
2. Verify DTC P003A, P0045–P0048, P0071–P0074, P00C7, P0106–P0108, P0116–P0119, P0128, P02E1, P02E8, P02E9, P111E, P122D, P169E, P169F, P16FA, P16FC, P2227–P2230, U0654, U0656 is not set. ⇒ If any of the DTCs are set Refer to: Diagnostic Trouble Code (DTC) List - Vehicle ⇓ If none of the DTCs are set
3. Verify the scan tool parameter: MAP Sensor = The value should be within the range listed in the table: Altitude Versus Barometric Pressure ⇒ If not in the specified range Refer to: DTC P0106, P0107, or P0108 ⇓ If in the specified range
4. Engine » Idling — At normal operating temperature.
5. Verify the scan tool parameter: MAP Sensor = The value should change with accelerator pedal input. ⇒ If the value does not change Refer to: DTC P0106, P0107, or P0108 ⇓ If the value changes
6. Perform the scan tool control function: Turbocharger Vane Position » Increase & Decrease Verify the scan tool parameter: Turbocharger Vane Position Sensor = Desired Turbocharger Vane Position ⇒ If not the specified state Refer to: Circuit/System Testing ⇓ If the specified state
7. Perform the scan tool control function: Exhaust Gas Recirculation » Closed
8. Verify the scan tool parameter: Induction System Leak Indication = 0.75:1 to 1.25:1 — Stable ⇒ If not in the specified range Refer to: Circuit/System Testing ⇓ If in the specified range
9. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data. Verify the DTC does not set. ⇒ If the DTC sets Refer to: Circuit/System Testing ⇓ If the DTC does not set
10. All OK. Circuit/System Testing

Note

Circuit/System Verification must be performed before proceeding to Circuit/System Testing.

1. Verify the conditions listed below do not exist: B65 Intake Manifold Pressure and Air Temperature Sensor – Leaking @ O-Ring — Missing / Visible Damage – Restricted — Moisture / Ice – Skewed B75 Mass Air Flow Sensor — Contamination of the measuring element / Cracked / Loose Clamps / Visible Damage / Water intrusion M103 Turbocharger Vane Position Actuator — Linkage Binding or Sticking / Loose / Worn / Visible Damage Q14A Exhaust Gas Recirculation Valve 1 — Leaking / Restricted / Visible Damage Q14B Exhaust Gas Recirculation Valve 2 — Leaking / Restricted / Visible Damage Q38 Throttle Body – Coking / Loose Clamps / Visible Damage – Restricted — Moisture / Ice Air Cleaner Element — Dirty / Restricted Charge Air Cooler – Leaking / Incorrect connection – Restricted — Moisture / Ice Refer to: Component/System Leak Test Engine — Mechanical Condition » Refer to: Symptoms - Engine Mechanical Exhaust System — Leaking / Restricted / Visible Damage » Refer to: Symptoms - Engine Exhaust Intake Air Duct — Cracked / Loose Clamps / Restricted — Collapsed / Visible Damage Intake Manifold — Cracked — Leaking / Loose Clamps / Restricted / Visible Damage Mechanically damaged turbocharger. — Refer to: Compressor Air Intake Turbocharger System Description Positive Crankcase Ventilation System – Leaking @ O-Ring — Missing / Visible Damage – Restricted — Moisture / Ice – Incorrect connection / Leaking / Restricted ⇒ If a condition exists Repair or replace as necessary ⇓ If no condition is found
2. Replace the component: Turbocharger Repair Instructions Perform the Diagnostic Repair Verification after completing the repair: Diagnostic Repair Verification Compressor Air Intake Turbocharger Replacement Additional Procedures Turbocharger/Supercharger Boost Control Initial Position Learn Perform only when the following component/system is replaced or serviced: — Turbocharger — Cleaned / Replaced

Note

The DTC causing the Driver Information Center message/speed limitation to set must run and pass before the message/speed limitation will clear. This may require driving the vehicle.

1. Ignition » On / Vehicle » In Service Mode
2. Verify that all scan tool Event Data parameters under the following data list displays No: Exhaust Gas Recirculation System Malfunction Warning Event Data ⇒ If not the specified state Operate the vehicle within the Conditions for Running the DTC for the DTC identified by the Event Data parameter displaying Yes. ⇓ If the specified state
3. All OK.