P0068
DTC P0068 or P1101
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 V.
* The throttle actuator control system is not in reduced power mode.
* The DTC runs continuously when the above conditions are met.
DTC P1101
* DTCs P0102, P0103, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0128, P0335, or P0336 are not set
* The engine speed is between 500-6,800 RPM
* The engine coolant temperature (ECT) is between -7 and +125°C (+19 and +257°F).
* The intake air temperature (IAT) sensor 1 is between -20 and +125°C (-4 to +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
* DTC P0068 is a type A DTC.
* 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.
Reference Information
Schematic Reference
Engine Controls Schematics [1][2]Electrical Diagrams
Connector End View Reference
Component Connector End Views Sunshade - Left (DH6)
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 Control Module References for scan tool information
Circuit/System Testing
1. Verify none of the following conditions exist:
* The air intake duct system for loose clamps, cracks, or other damage
* The air intake duct system for being collapsed or restricted
* Restricted air filter
* Q38 throttle body for dirt, debris, and coking. Also, throttle body blade or shaft damage. Refer to Throttle Body Inspection and Cleaning Procedures for further diagnosis.
* Splits, kinks, or improper connections at the vacuum hoses
* Missing, restricted, or leaking exhaust components-Refer to Symptoms - Engine Exhaust Symptoms - Engine Exhaust for further diagnosis.
* Vacuum leaks at the intake manifold and Q38 throttle body.
• If a condition exists, repair as necessary.
2. Ignition ON, observe the diagnostic trouble code (DTC) information with a scan tool. Verify that DTC P0641, P0651, P0697, or P06A3 is not set.
• If any of the above DTCs are set, refer to DTC P0641, P0651, P0697, or P06A3 (ECM) Powertrain Management (ECM) for DTC P0641, P0651, P0697, or P06A3 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 DTC P0106 (LF1, LFW, or LFX) P0106 for DTC P0106.
4. Engine idling, observe the MAP Sensor kPa parameter. The reading should be between 26-52 kPa (3.8-7.5 psi).
• If not within the specified range, refer to DTC P0106 (LF1, LFW, or LFX) P0106 for further diagnosis.
5. Engine idling, observe the scan tool MAF Sensor parameter. The reading should be between 2.5-8.8 g/s depending on the engine coolant temperature (ECT) and barometric (BARO) pressure.
• If not within the specified range, refer to DTC P0101 P0101 for further diagnosis.
6. Verify the scan tool MAF Sensor g/s parameter changes smoothly and gradually as the engine speed is increased and decreased while performing the actions listed below.
1. Engine idling
2. Perform the scan tool snapshot function.
3. Increase the engine speed slowly to 3,000 RPM and then back to idle.
4. Exit from the scan tool snapshot and review the data.
5. Observe the MAF Sensor parameter frame by frame with a scan tool.
• If the MAF Sensor g/s parameter does not change smoothly and gradually, refer to DTC P0101 P0101 for further diagnosis.
7. If all conditions test normal, test the engine for a mechanical condition. Refer to Symptoms - Engine Mechanical Symptoms - Engine Mechanical for further diagnosis.
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the repair.
* Throttle Body Assembly Replacement Removal and Replacement
* Air Cleaner Element Replacement Service and Repair