PRE-RELEASE
DTC P0101 (LAU)
| DTC P0101 (LAU) |
| 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 P0101
Mass Air Flow (MAF) Sensor Performance
| Diagnostic Fault Information |
| Circuit | Short to Ground | High Resistance | Open | Short to Voltage | Signal Performance |
| Ignition Voltage | P0102 | P0101 | P0102 | - | P0101, P0103 |
| MAF Sensor Signal | P0102 | P0102 | P0102 | P0102 | P0101, P0103, P1101 |
| Ground | - | P0102 | P0102 | - | P0102 |
| Typical Scan Tool Data |
MAF Sensor
| Circuit | Short to Ground | Open | Short to Voltage |
| Operating Conditions: Engine running at various operating conditions Parameter Normal Range: 2,000-10,000 Hz | |||
| Ignition 1 Voltage | 0 Hz | 0 Hz | - |
| MAF Sensor Signal | 0 Hz | 0 Hz | 0 Hz |
| Ground | - | 0 Hz | - |
| Circuit/System Description |
The mass air flow (MAF) sensor is located in the air intake duct. The MAF sensor is an airflow meter that measures the amount of air that enters the engine. The MAF sensor uses a hot film that is cooled by air flowing past the sensing film as air enters the engine. The amount of cooling is proportional to the amount of the air flow. As the air flow increases, more current is required in order to maintain the hot film at a constant temperature. The engine control module (ECM) uses the MAF sensor in order to provide the correct fuel delivery for all operating conditions.
| Conditions for Running the DTCs |
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DTCs P0102, P0103, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0128, P0335 or P0336 are not set.
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Engine is running.
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The engine coolant is between 69-127°C (156-261°F).
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The intake air temperature is between -20 and +125°C (-4 and +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 engine control module (ECM) detects that the actual measured airflow from the MAF and throttle position sensors is not within range of the calculated airflow that is derived from the system of models for greater than 2 s.
| Action Taken When the DTC Sets |
DTCs P0101 and P1101 are Type B DTCs.
| Conditions for Clearing the MIL/DTC |
DTCs P0101 and P1101 are Type B DTCs.
| Diagnostic Aids |
A steady or intermittent high resistance of 15 Ω or greater on the ignition voltage circuit will cause the MAF sensor signal to be increased by as much as 60 g/s.
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Certain aftermarket air filters may cause this DTC to set.
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Certain aftermarket air induction systems may cause this DTC to set.
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Modifications to the air induction system may cause this DTC to set.
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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
Special Tools
J 38522 Variable Signal Generator
| Circuit/System Verification |
| 1. |
Verify that DTCs P0641, P0651, P0685, P0689, P0690, P0697, P06A3, or B1380 are not set.
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| 2. |
If any of the DTCs are set, refer to
Diagnostic Trouble Code (DTC) List - Vehicle
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| 3. |
Verify that restrictions do not exist in the exhaust system. Refer to
Restricted Exhaust
.
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| 4. |
Engine operating at idle, observe the scan tool MAF Sensor parameter. The reading should be between 2,000-3,800 Hz depending on the ECT.
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| 5. |
A wide open throttle (WOT) acceleration from a stop should cause the MAF Sensor parameter on the scan tool to increase rapidly. This increase should be from 2-6 g/s at idle to greater than 180 g/s at the time of the 1-2 shift.
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Use the scan tool and compare the MAF Sensor parameter to a known good vehicle, under various operating conditions.
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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.
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| Circuit/System Testing |
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Verify the integrity of the entire air induction system by inspecting for the following conditions:
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Any damaged components
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Loose or improper installation
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An air flow restriction
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Any vacuum leaks
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Water intrusion
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In cold climates, inspect for any snow or ice buildup
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Inspect the B75 MAF sensor element for contamination.
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| 2. |
Ignition OFF, disconnect the harness connector at the B75 MAF sensor.
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| 3. |
Remove the fuse that supplies B+ to terminal 56 X2 of the ECM.
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| 4. |
Ignition OFF and all vehicle systems OFF. It may take up to 2 minutes for all vehicle systems to power down. Test for less than 5 Ω between the ground circuit terminal 2 and ground.
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| 5. |
If greater than the specified range, test the ground circuit for an open/high resistance.
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Install fuse that supplies B+ to terminal 56 X2 of the ECM.
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Ignition ON, verify that a test lamp illuminates between the ignition circuit terminal 4 and ground. |
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Warning
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If the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance. If the circuit tests normal and the ignition circuit fuse is open, test all the components connected to the ignition circuit and replace as necessary.
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Ignition ON, test for 4.8-5.2 V between the signal circuit terminal 5 and ground.
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If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K20 ECM.
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If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the K20 ECM.
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Ignition OFF, connect the red lead of the J 38522 to the signal circuit terminal 5 at the B75 MAF sensor harness connector. Connect the battery voltage supply to B+, and the black lead to ground.
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Set the J 38522 Signal switch to 5 V, the Frequency switch to 5K, and the Duty Cycle switch to Normal.
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| 14. |
Engine idling, observe the scan tool MAF Sensor Hz parameter. The parameter should be between 4,950-5,050 Hz.
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If the MAF Sensor parameter is not within the specified range, replace the K20 ECM.
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If all circuits test normal, test or replace the B75 MAF sensor.
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| Repair Instructions |
Perform the Diagnostic Repair Verification after completing the repair.
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Engine Coolant Temperature Sensor Replacement (LAU)
Engine Coolant Temperature Sensor Replacement (LF1)
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Mass Airflow Sensor with Intake Air Temperature Sensor Replacement (LAU)
Mass Airflow Sensor with Intake Air Temperature Sensor Replacement (LF1)
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Control Module References
for ECM replacement, setup, and programming
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