DTC P0102 Mass Air Flow (MAF) Sensor Circuit Low Frequency. Chevrolet Chevy C Silverado

For 1990-2009 cars only

Makes 🢒 Chevrolet 🢒 2000 🢒 Chevy C Silverado - 2WD 🢒 Engine 🢒 Engine Controls - 4.3L 🢒 DTC P0102 Mass Air Flow (MAF) Sensor Circuit Low Frequency

Handling ESD Sensitive Parts Notice
Engine Controls Components
IAC, ECT, TPS, MAF, G103, MAP, IAT, VCM
OBD II Symbol Description Notice
Handling ESD Sensitive Parts Notice
VCM Connector End Views

Circuit Description

The mass air flow (MAF) sensor is an air flow meter. The control module supplies the MAF sensor a signal circuit. An ignition positive voltage circuit and a ground circuit are supplied to the MAF sensor by independent circuits. The MAF sensor heats a wire element, or grid, within the MAF sensor in order to maintain a calculated temperature. As inlet air flows across and cools the grid, the MAF sensor increases current flow to the grid in order to maintain the constant grid temperature. The MAF sensor converts the grid current flow into a frequency signal. The control module converts the MAF signal frequency into a grams per second value. During low air flow rates, such as at engine idle, the MAF sensor produces a low frequency signal. During high air flow rates, such as at wide open throttle-road load, the MAF sensor increases the frequency signal. The control module monitors the MAF sensor signal frequency in order to calculate the flow and mass of the air entering the engine.

This DTC is designed to detect an unusually low MAF sensor signal frequency. If a MAF sensor frequency is detected by the VCM to be below the possible range of a normally operating MAF sensor, this DTC will set.

Conditions for Running the DTC

•	The engine is running.

•	The engine speed is more than 300 RPM.

•	The system voltage is more than 8 volts.

Conditions for Setting the DTC

The MAF frequency is 10 Hz or less for more than 1 second.

Action Taken When the DTC Sets

•	The control module illuminates the malfunction indicator lamp (MIL) if a failure is detected during 2 consecutive key cycles.

•	The control module sets the DTC and records the operating conditions at the time the diagnostic failed. The failure information is stored in the scan tool Freeze Frame/Failure Records.

Conditions for Clearing the MIL or DTC

•	The control module turns OFF the MIL after 3 consecutive drive trips when the test has run and passed.

•

A history DTC will clear if no fault conditions have been detected for 40 warm-up cycles. A warm-up cycle occurs when the coolant temperature has risen 22°C (40°F) from the startup coolant temperature and the engine coolant reaches a temperature that is more than 70°C (158°F) during the same ignition cycle.

•	Use a scan tool in order to clear the DTCs.

Diagnostic Aids

Check for the following conditions:

•	A misrouted harness -- Inspect the mass air flow (MAF) sensor harness in order to ensure that it is not routed too close to high voltage wires such as the spark plug leads.

•	A damaged harness -- Inspect the wiring harness for damage. If the harness appears OK, observe the scan tool while you move the connectors and the wiring harnesses that are related to the MAF sensor. A change in the display indicates the location of the fault.

•	A plugged intake air duct or filter element -- A wide open throttle acceleration from a stop should cause the MAF displayed on a scan tool to increase from approximately 4-7 g/s at idle to 100 g/s or more at the time of the 1-2 shift. If this does not occur, check for a restriction.

An intermittent may be caused by any of the following conditions:

•	A poor connection

•	Rubbed through wire insulation

•	A broken wire inside the insulation

Thoroughly inspect any circuitry that is suspected of causing the intermittent complaint. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.

If a repair is necessary, refer to Wiring Repairs or Connector Repairs in Wiring Systems.

Test Description

The numbers below refer to step numbers on the diagnostic table.

This step verifies that the problem is present at idle.

A voltage reading of less than 4 volts or more than 6 volts at the MAF sensor signal circuit indicates a malfunction in the wiring or a faulty connection. Disconnecting the MAF sensor during this step could set a false DTC P0113.

This step verifies that the ignition positive voltage and a good ground are available at the MAF sensor.

This step determines if the fuse is open. If the fuse is open, locate and repair the short to ground in the ignition positive voltage circuit. A short to ground in the ignition positive voltage circuit can affect other components. Check for other DTCs. The source of the short to ground could also be caused by a component that shares the same circuit.

Step

Action

Value(s)

Yes

Did you perform the Powertrain On-Board Diagnostic (OBD) System Check?

Go to Step 2

Go to Powertrain On Board Diagnostic (OBD) System Check

Start the engine.
With the engine idling, monitor the MAF reading on the scan tool.

Is the MAF reading below the specified value?

2 g/s

Go to Step 4

Go to Step 3

Turn ON the ignition, leaving the engine OFF.
Review the scan tool Failure Records data.
Record the scan tool Failure Records data.
Operate the vehicle within the Failure Records conditions as noted.
Use a scan tool in order to monitor the Specific DTC information for DTC P0102.

Does the scan tool indicate DTC P0102 Failed This Ignition?

Go to Step 4

Go to Diagnostic Aids

Inspect the MAF ignition positive voltage fuse. Refer to Electrical Center Identification Views in Wiring Systems.

Is the fuse open?

Go to Sep 11

Go to Step 5

Check for:

•	Objects blocking the MAF sensor inlet screen

•	A crankcase ventilation valve that is:

•	Malfunctioning

•

Missing

•	Improperly installed

•	Vacuum leaks in the :

-	Throttle body

-	Exhaust gas recirculation (EGR) valve flange and pipes

-	Manifold absolute pressure (MAP) sensor seal

-	Evaporative emission (EVAP) canister purge valve seal

-	Fuel meter body seal

If you find a problem, repair the condition as necessary.

Did you find a problem?

Go to Step 17

Go to Step 6

Turn OFF the ignition.
Disconnect the MAF sensor harness connector.
Turn ON the ignition, leaving the engine OFF.
Use a DMM in order to measure the voltage between the MAF sensor signal circuit and the battery ground.

Is the voltage near the specified value?

5.0 V

Go to Step 7

Go to Step 10

Connect a test lamp between the MAF sensor ignition positive voltage and the ground circuits at the MAF sensor harness connector.

Is the test lamp ON?

Go to Step 9

Go to Step 8

Connect a test lamp between the MAF sensor ignition positive voltage circuit and the battery ground.

Is the test lamp ON?

Go to Step 12

Go to Step 13

Check for a faulty connection at the MAF sensor.
Repair the connection as necessary. Refer to Connector Repairs in Wiring Systems.

Did you find a problem?

Go to Step 17

Go to Step 14

Check the MAF signal circuit between the VCM and the MAF sensor for:

1.1.

An open

1.2.	A short to ground

1.3.	A short to the MAF ground circuit

1.4.	An short to voltage

Repair the circuit as necessary. Refer to Wiring Repairs in Wiring Systems.

Did you find a problem?

Go to Step 17

Go to Step 15

Check for a short to ground in the MAF ignition positive voltage circuit.
Repair the circuit as necessary. Refer to Wiring Repairs in Wiring Systems.
Replace the open fuse.

Is the action complete?

Go to Step 17

Locate the open in the ground circuit to the MAF sensor.
Repair the circuit as necessary. Refer to Wiring Repairs in Wiring Systems.

Is the action complete?

Go to Step 17

Check the ignition positive voltage circuit to the MAF sensor for an open.
Repair the circuit as necessary. Refer to Wiring Repairs in Wiring Systems.

Is the action complete?

Go to Step 17

Replace the MAF sensor. Refer to Mass Airflow Sensor/Intake Air Temperature Sensor Replacement .

Is the action complete?

Go to Step 17

Check for a faulty connection at the VCM connector.
Repair the circuit as necessary. Refer to Connector Repairs in Wiring Systems.

Did you find a problem?

Go to Step 17

Go to Step 16

Important: The replacement VCM must be programmed.

Replace the VCM. Refer to VCM Replacement/Programming .

Is the action complete?

Go to Step 17

Use the scan tool in order to clear the DTCs.
Start the engine.
Allow the engine to idle until the engine reaches the normal operating temperature.
Select the DTC, then select the Specific DTC function.
Enter the DTC number which was set.
Operate the vehicle within the Conditions for Setting this DTC until the scan tool indicates the diagnostic Ran.

Does the scan tool indicate the diagnostic Passed?

Go to Step 18

Go to Step 2

Does the scan tool display any additional undiagnosed DTCs?

Go to the applicable DTC table

System OK