PRE-RELEASE
DTC P0102 or P0103
| DTC P0102 or P0103 |
| 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 Descriptors |
DTC P0102
Mass Air Flow (MAF) Sensor Circuit Low Frequency
DTC P0103
Mass Air Flow (MAF) Sensor Circuit High Frequency
| Diagnostic Fault Information |
| Circuit | Short to Ground | High Resistance | Open | Short to Voltage | Signal Performance |
| Ignition 1 Voltage | P0102 | P0101 | P0102 | P0690 | 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 integrated with the intake air temperature (IAT) sensor. The MAF sensor is an air flow meter that measures the amount of air entering the engine. The engine control module (ECM) uses the MAF sensor signal to provide the correct fuel delivery for all engine speeds and loads. A small quantity of air entering the engine indicates a deceleration or idle condition. A large quantity of air entering the engine indicates an acceleration or high load condition. The MAF/IAT sensor has the following circuits:
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Ignition 1 voltage circuit
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Ground circuit
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MAF sensor signal circuit
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IAT sensor signal circuit
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IAT low reference circuit
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The ECM applies 5 V to the MAF sensor on the MAF sensor signal circuit. The sensor uses the voltage to produce a frequency based on the inlet air flow through the sensor bore. The frequency varies in a range of near 2,000 Hertz at idle to near 10,000 Hertz at maximum engine load.
| Conditions for Running the DTC |
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The engine is running for more than 1 s.
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The ignition 1 signal is greater than 8 V.
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The above conditions are met for greater than 1 s.
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The DTC runs continuously once the above conditions are met.
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| Conditions for Setting the DTC |
P0102
The ECM detects that the MAF Sensor Signal parameter is less than 500 Hz for greater than 10 s.P0103
The ECM detects that the MAF Sensor Signal parameter is greater than 14,500 Hz for greater than 10 s.| Action Taken When the DTC Sets |
DTCs P0102 and P0103 are Type B DTCs.
| Conditions for Clearing the MIL/DTC |
DTCs P0102 and P0103 are Type B DTCs.
| Diagnostic Aids |
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A steady or intermittent high resistance of 15 Ω or greater on the ignition 1 voltage circuit will cause the MAF sensor signal to be increased by as much as 60 g/s.
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Depending on the current ambient temperature, and the vehicle operating conditions, a MAF sensor signal circuit that is shorted to the IAT signal circuit will cause the MAF sensor signal to be skewed or erratic. Additionally, it may cause a rapid fluctuation in the IAT Sensor parameter.
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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 P0685, P0690 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. |
Engine running, observe the scan tool MAF Sensor Signal parameter. The reading should be between 1,700-3,800 Hz depending on the engine coolant temperature (ECT).
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| 4. |
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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Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. 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 |
| 1. |
Verify that DTCs P0685, P0690 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 the integrity of the air induction system by inspecting for the following conditions:
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Loose or improper installation
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Water intrusion
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| 4. |
Ignition OFF, disconnect the harness connector at the B75B MAF/IAT sensor.
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| 5. |
Remove the fuse that supplies B+ to terminal 52 X1 of the ECM.
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| 6. |
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 B and ground.
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If greater than the specified range, test the ground circuit for an open/high resistance.
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Install the fuse that supplies B+ to terminal 52 X1 of the ECM.
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Ignition ON, verify that a test lamp illuminates between the ignition circuit terminal C and ground.
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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.
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If the circuit tests normal and the fuse is open, test all the components connected to the circuit, and repair or replace as necessary.
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Ignition ON, test for 4.8-5.2 V between the signal circuit terminal A 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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| 15. |
Ignition OFF, connect the red lead of the J 38522 to the signal circuit terminal A at the B75B MAF/IAT sensor harness connector. Connect the battery voltage supply to B+, and the black lead to ground.
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| 16. |
Set the J 38522 signal to 5 V, the Frequency to 5K, and the Duty Cycle to Normal.
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| 17. |
Engine idling, observe the scan tool MAF Sensor parameter. The scan tool MAF Sensor parameter should be between 4,950-5,050 Hz.
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| 18. |
If the MAF Sensor parameter is not within the specified range, replace the K20 ECM.
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| 19. |
If all other circuits test normal, replace the B75B MAF/IAT sensor.
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| Repair Instructions |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
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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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