P0068
DTC P0068 or P1101 (LDK_LHU With Turbocharger) (2.0L With Turbocharger)
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) provides an overview of each diagnostic category.
DTC Descriptor
DTC P0068
- Throttle Body Airflow Performance
DTC P1101
- Intake Air Flow System Performance
Circuit/System Description
The engine control module (ECM) compares actual airflow based on throttle position (TP) to a calculated airflow based on manifold absolute pressure (MAP) sensor, and mass air flow (MAF).
Conditions for Running the DTC
DTC P0068
* The engine speed is greater than 800 RPM.
* The ignition voltage is greater than 6.0 volts.
* The throttle actuator control system is not in reduced power mode.
* The DTC runs continuously when the above conditions are met.
DTC P1101
* DTCs P0096, P0097, P0098, P0102, P0103, P0107, P0108, P0111, P0112, P0113, P0016, P0117, P0118, P0119, P0128, P0236, P0237, P0238, P0335, P0336, P0401, P0405, P0406, P042E, P2227, P2228, P2229, or P2230 are not set
* The engine speed is between 400-6,000 RPM
* The ECT Sensor is between -7 and +125°C (+19 and +257°F).
* The IAT 1 Sensor is between -20 and +125°C (-4 and +257°F).
* The DTC runs continuously when the above conditions are met.
Conditions for Setting the DTC
The ECM detects that the actual airflow rate is greater than the calculated airflow.
Action Taken When the DTC Sets
P0068
* DTC P0068 is a Type A DTC.
* The control module commands the throttle actuator control (TAC) system to operate in the Reduced Engine Power mode.
* A message center or an indicator displays Reduced Engine Power.
* Under certain conditions the control module commands the engine OFF.
P1101
DTC P1101 is a Type B DTC.
Conditions for Clearing the DTC
* DTC P0068 is a Type A DTC.
* DTC P1101 is a Type B DTC.
Diagnostic Aids
* Inspect for a condition in which the throttle valve may have been held open. For example, ice may have formed in the throttle bore causing the throttle valve not to close.
* Certain aftermarket air filters may cause a DTC to set.
* Certain aftermarket air induction systems may cause a DTC to set.
* Modifications to the air induction systems may cause a DTC to set.
* A high resistance condition on the throttle position and throttle actuator control circuits could cause a DTC to set.
* An inaccurate MAF sensor, an intake air flow restriction, any unmetered air that enters the engine downstream of the MAF sensor, or an air induction leak may cause a DTC to set.
* A low battery condition may cause a DTC to set.
Reference Information
Schematic Reference
Engine Controls Schematics ([1][2]Electrical Diagrams)
Connector End View Reference
Component Connector End Views (Connector End Views By Name)
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 Testing
1. Inspect for the following conditions:
* The air intake duct system for loose clamps, cracks, any type of leak, or other damage
* The air intake duct system for being collapsed or any type of restriction
* The mass airflow sensor is installed correctly. The arrow indicates direction of airflow and the tabs of the hoses and notches of the sensor must be aligned. Refer to Mass Airflow Sensor with Intake Air Temperature Sensor Replacement (Service and Repair).
* Restricted air filter
* Throttle body for dirt, debris, and coking-Refer to Throttle Body Cleaning (Procedures).
* A damaged throttle body blade or shaft
* Splits, kinks, or improper connections at the vacuum hoses
* Missing, restricted, or leaking exhaust components-Refer to Fastener Tightening Specifications (Mechanical Specifications).
* Vacuum leaks at the intake manifold, throttle body, and injector O-rings
• If a condition exists, repair as necessary.
2. Ignition ON, observe the diagnostic trouble code (DTC) information with a scan tool. Verify that no other DTCs are not set.
• If any other DTCs are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle (Diagnostic Trouble Code (DTC) List - Vehicle) for further diagnosis.
3. Determine the current vehicle testing altitude. Compare the MAP sensor pressure parameter to the reading in the Altitude Versus Barometric Pressure (Altitude Versus Barometric Pressure) table. The MAP sensor pressure parameter should be within the specified range indicated in the table.
• If the MAP sensor pressure is not within the range specified for your altitude, refer to Diagnostic Trouble Code (DTC) List - Vehicle (Diagnostic Trouble Code (DTC) List - Vehicle) for P0106.
4. Engine idling, observe the MAP Sensor parameter. The reading should be between 26-52 kPa.
• If not within the specified range, refer to Diagnostic Trouble Code (DTC) List - Vehicle (Diagnostic Trouble Code (DTC) List - Vehicle) for P0106.
5. Idle the engine. Observe the MAP Sensor kPa parameter with a scan tool. Increase the engine speed slowly and then back to idle. The MAP sensor kPa should change smoothly and gradually as engine speed is increased and returned to idle.
• If the MAP sensor kPa does not change, refer to Diagnostic Trouble Code (DTC) List - Vehicle (Diagnostic Trouble Code (DTC) List - Vehicle) for P0106.
Note: If there is a condition with the throttle body, the TAC Motor Command parameter will go to 99 % for a predetermined amount of time and then a DTC sets. Once a DTC is set, the TAC Motor Command parameter will go to 0 % and the TAC Motor parameter will display Disabled.
6. Perform the Throttle Sweep Test while observing the TAC Motor parameter with a scan tool. The TAC Motor parameter should display Enabled while the Throttle Sweep Test is in progress.
Note: Before replacing the throttle body assembly, make sure the throttle control circuits are not shorted to B+.
• If not the specified value, replace the throttle body assembly.
7. Inspect the throttle body for the following conditions:
* Loose or damaged throttle blade
* Broken throttle shaft
* Any throttle body damage
• If any of these conditions exist, replace the throttle body assembly.
8. Use the scan tool snapshot function to take a snapshot of the engine data list while performing the actions listed below.
1. Engine idling.
2. Increase the engine speed slowly to 3,000 RPM and then back to idle.
3. Exit from the scan tool snapshot and review the data.
4. Observe the mass air flow (MAF) sensor parameter frame by frame with a scan tool. The MAF sensor g/s parameter should change smoothly and gradually as the engine speed is increased and then returned to idle.
• If the MAF sensor g/s does not change smoothly and gradually, replace the B75B mass air flow /intake air temperature sensor.
9. If all conditions test normal, test the engine for a mechanical condition. Refer to Symptoms - Engine Mechanical (Symptoms - Engine Mechanical).
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.
* Mass Airflow Sensor with Intake Air Temperature Sensor Replacement (Service and Repair)
* Throttle Body Assembly Replacement (Removal and Replacement)
* Air Cleaner Element Replacement (Service and Repair)