DTC P0102 or P0103. Chevrolet Uplander

For 1990-2009 cars only

Makes 🢒 Chevrolet 🢒 2006 🢒 Uplander - 4WD 🢒 Engine 🢒 Engine Controls - 3.9L 🢒 DTC P0102 or P0103

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

Important: Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

Circuit	Short to Ground	High Resistance	Open	Short to Voltage	Signal Performance
Ignition 1 Voltage	P0102	P0102	P0101	--	P0101, P0103
MAF Sensor Signal	P0102	P0102	P0102	P0102	P0101, P0103, P1101
Ground	--	P0102	P0102	--	P0102

The mass air flow (MAF) sensor is an air flow meter that measures the amount of air entering the engine. The control module 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 sensor has the following circuits:

•	An ignition 1 voltage circuit

•	A ground circuit

•	A signal circuit

The control module applies a voltage to the sensor on the signal circuit. The sensor uses the voltage to produce a frequency based on the inlet air flow through the sensor bore. The frequency varies within a range of near 2,000 Hertz at idle to near 10,000 Hertz at maximum engine load.

Conditions for Running the DTC

•	The engine is cranking or running.

•	The engine speed is more than 50 RPM.

•	The ignition 1 signal is more than 8 volts.

•	The throttle position (TP) indicated angle parameter is more than 3.5 percent.

•	The above conditions are met for more than 0.5 second.

Conditions for Setting the DTC

P0102

The control module detects that the MAF sensor frequency signal is less than 1,200 Hertz for more than 10 seconds.

P0103

The control module detects that the MAF sensor frequency signal is more than 11,500 Hertz for more than 10 seconds.

Action Taken When the DTC Sets

DTC P0102 and DTC P0103 are Type B DTCs

Conditions for Clearing the DTC

DTC P0102 and DTC P0103 are Type B DTCs

Conditions for Clearing the MIL/DTC

•	The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.

•	A current DTC, Last Test Failed, clears when the diagnostic runs and passes.

•	A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.

•	Clear the MIL and the DTC with a scan tool.

Diagnostic Aids

•	Inspect the harness of the MAF sensor to verify that it is not routed too close to the following components:

-	The secondary ignition wires or coils

-	Any solenoids

-	Any relays

-	Any motors

•

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 3-10 g/s at idle to 150 g/s or more at the time of the 1-2 shift. If the increase is not observed, inspect for a restriction in the induction system or the exhaust system.

•	A high resistance may cause a driveability concern before this DTC sets.

Reference Information

Schematic Reference

Engine Controls Schematics

Connector End View Reference

•	Engine Controls Connector End Views

•	Engine Control Module Connector End Views

Electrical Information Reference

•	Circuit Testing

•	Connector Repairs

•	Testing for Intermittent Conditions and Poor Connections

•	Wiring Repairs

Special Tools Required

J 38522 Variable Signal Generator

DTC Type Reference

•	Powertrain Diagnostic Trouble Code (DTC) Type Definitions

•	Diagnostic Trouble Code (DTC) Types

Circuit/System Testing

Inspect for any contamination, water intrusion, or debris on the sensing elements of the MAF sensor.

⇒	If debris is present, clean the sensor. If the sensor cannot be cleaned, replace the sensor.

Ignition OFF, disconnect the harness connector at the MAF sensor.
Test for less than 5 ohms of resistance between the ground circuit terminal C and ground.

⇒	If greater than the specified range, test the ground circuit for an open/high resistance.

Ignition ON, verify that a test lamp illuminates between the ignition 1 circuit terminal B and ground.

⇒	If the test lamp does not illuminate, test the ignition 1 circuit for a short to ground or an open/high resistance. If the circuit tests normal and the fuse for the ignition 1 voltage circuit is open, test or replace the MAF sensor.

Ignition ON, test for 4.8-5.2 volts between the signal circuit terminal A and ground.

⇒	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 control module.

⇒	If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the control module.

Important: To set up the J 38522 variable speed generator, place the duty cycle to normal, the frequency to 5 K, and the signal switch to 5 volts.

Turn OFF the ignition and connect the red lead of the J 38522 to the signal circuit at the MAF sensor harness connector and the black lead to a good ground.
Start the engine and observe the MAF sensor for 4,950-5,025 Hz with a scan tool.

⇒	If the MAF sensor is not within the specified range, test for intermittent or poor connection at the control module. If circuit tests normal, replace the control module.

⇒	If the MAF sensor is within the specified range, test for intermittent or poor connection at the MAF sensor. If tests normal, replace the MAF sensor.

Repair Instructions

Important: Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

•	Mass Airflow Sensor/Intake Air Temperature Sensor Replacement

•	Control Module References for control module replacement, setup, and programming