PRE-RELEASE
DTC P0068 or P1101
| DTC P0068 or P1101 |
| Diagnostic Instructions |
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Perform the
Diagnostic System Check - Vehicle
prior to using this diagnostic procedure.
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Review
Strategy Based Diagnosis
for an overview of the diagnostic approach.
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Diagnostic Procedure Instructions
provides an overview of each diagnostic category.
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| 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
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The engine speed is greater than 800 RPM.
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The ignition voltage is greater than 6.0 V.
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The throttle actuator control system is not in reduced power mode.
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The DTC runs continuously once the above conditions are met.
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DTC P1101
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DTCs P0102, P0103, P0107, P0108, P0112, P0113, P0117, P0118, P0335, P0336 are not set
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The engine speed is between 400-7,000 RPM
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The engine coolant temperature (ECT) is between 69-127°C (156-260°F).
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The intake air temperature (IAT) is between -20 to +125°C (-4 to +257°F).
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The DTC runs continuously once the above conditions are met.
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| 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 |
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DTC P0068 is a type A DTC.
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DTC P1101 is a type B DTC.
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| Conditions for Clearing the DTC |
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DTC P0068 is a type A DTC.
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DTC P1101 is a type B DTC.
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| Reference Information |
Schematic Reference
Engine Controls Schematics (3.0L (LF1)) Engine Controls Schematics (2.8L (LAU))
Connector End View Reference
Component Connector End Views
Electrical Information Reference
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Circuit Testing
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Connector Repairs
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Testing for Intermittent Conditions and Poor Connections
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Wiring Repairs
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DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Control Module References for scan tool information
| Circuit/System Testing |
| 1. |
Verify none of the following conditions exist:
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The air intake duct system for loose clamps, cracks, or other damage
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The air intake duct system for being collapsed or restricted
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The B75 mass airflow sensor is installed correctly.
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Restricted air filter
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Throttle body Q38 has dirt, debris, and coking. Also check if throttle body blade or shaft are damaged. Refer to
Throttle Body Inspection and Cleaning
for further diagnosis.
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Splits, kinks, or improper connections at the vacuum hoses
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Missing, restricted, or leaking exhaust components-Refer to
Symptoms - Engine Exhaust
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Vacuum leaks at the intake manifold and Q38 throttle body.
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| 2. |
If a condition exists, repair as necessary.
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| 3. |
Ignition ON, observe the diagnostic trouble code (DTC) information with a scan tool. Verify that DTC P0641, P0651, P0697, or P06A3 is not set.
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| 4. |
If any of the above DTCs are set, refer to
Diagnostic Trouble Code (DTC) List - Vehicle
for DTC P0641, P0651, P0697, or P06A3 diagnosis.
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| 5. |
Determine the current vehicle testing altitude. Compare the MAP-sensor pressure parameter to the reading in the table
Altitude versus barometric ressure.
T MAP-sensor pressure parameter should be within the specified range indicated in the table.
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| 6. |
If the MAP sensor pressure is not within the range specified for your altitude, refer to
Diagnostic Trouble Code (DTC) List - Vehicle
for DTC P0106.
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| 7. |
Engine idling, observe the MAP Sensor kPa parameter. The reading should be between 26-52 kPa (3.8-7.5 psi).
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| 8. |
If not within the specified range, refer to
Diagnostic Trouble Code (DTC) List - Vehicle
for DTC P0106.
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| 9. |
Use the scan tool snapshot function to take a snapshot of the engine data list while performing the actions listed below.
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| 9.1. |
Engine idling
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| 9.2. |
Increase the engine speed slowly to 3,000 RPM and then back to idle.
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| 9.3. |
Exit from the scan tool snapshot and review the data.
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| 9.4. |
Observe the MAF Sensor g/s 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.
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| 10. |
If the MAF Sensor g/s parameter does not change smoothly and gradually, refer to
Diagnostic Trouble Code (DTC) List - Vehicle
for DTC P0101.
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| 11. |
If all conditions test normal, test the engine for a mechanical condition. Refer to
Symptoms - Engine Mechanical
.
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| Repair Instructions |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
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Throttle Body Assembly Replacement (LAU)
Throttle Body Assembly Replacement (LF1)
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Air Cleaner Element Replacement (LAU)
Air Cleaner Element Replacement (LF1)
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