Service Information

Orlando

DTC P0101

Diagnostic Instructions

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

•	Review Strategy Based Diagnosis for an overview of the diagnostic approach.

•	Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptor

DTC P0101 00 : Mass Air Flow (MAF) Sensor Performance

Diagnostic Fault Information

Circuit	Short to Ground	Open/High Resistance	Short to Voltage	Signal Performance
Ignition Voltage	P0100 00	P0100 00	-	P0101 00
Signal Circuit	P0100 00	P0100 00, P0102 00	P0102 00	P0101 00
Ground	-	P0100 00, P0102 00	-	P0101 00

Typical Scan Tool Data

MAF Sensor

Circuit	Short to Ground	Open	Short to Voltage
*Operating Conditions:* Engine running *Parameter Normal Range:* 1 700-12 500 Hz
Ignition Voltage	65 535 Hz	65 535 Hz	-
Signal Circuit	65 535 Hz	65 535 Hz	65 535 Hz
Ground	-	65 535 Hz	-

The mass air flow (MAF) sensor is integrated with the inlet 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. The MAF/IAT sensor has the following circuits:

•	Ignition voltage

•	MAF and IAT sensor ground

•	MAF sensor signal

•	IAT sensor signal

The purpose of this diagnostic is to analyze the performance of the MAF sensor by comparing the measured airflow to the following 2 distinct models:

•	The first model is separated into two parts. The first part is based on basic engine parameters and uses engine speed, and throttle angle as inputs. The second part is derived from long term fuel trim, at cruising speed and the ECM is looking for an adaptive value to be within a calibrated range.

•	The second model uses the manifold absolute pressure (MAP) sensor for input, and the ECM is looking for an adaptation value to be within a calibrated range.

Conditions for Running the DTC

•	DTCs P0097 00, P0098 00, P0100 00, P0102 00, P0103 00, P0121 00, P0122 00, P0123 00, P0221 00, P0222 00, P0223 00, P0237 00, P0238 00, P0335 00, P0336 00, P2176 00, P2228 00, or P2229 00 are not set.

•	The engine is running.

•	The engine coolant temperature (ECT) is warmer than 10°C (50°F).

•	The ignition voltage signal is greater than 9 V.

•	The change in the throttle position is less than 2%.

•	This DTC runs continuously within the enabling conditions.

Conditions for Setting the DTC

•	The ECM detects that the measured MAF is not within range of the calculated airflow based on throttle angle and engine speed.

•	The ECM detects a significant error in the long term fuel trim at cruising speed.

•	The ECM detects that the measured MAF is not within range of the calculated model that is derived from MAP.

Action Taken When the DTC Sets

•	DTC P0101 00 is a Type B DTC.

•	The ECM will disable boost control and limit the system to mechanical boost only, resulting in decrease in engine power.

•	The ECM will switch to a default calculated MAF sensor value based on engine speed and throttle position.

Conditions for Clearing the DTC

DTC P0101 00 is a Type B DTC.

Diagnostic Aids

•

The charge air cooler is connected to the turbocharger and to the throttle body by flexible duct work that requires the use of special high torque fastening clamps. These clamps cannot be substituted. In order to prevent any type of air leak when servicing the duct work, the tightening specifications and proper positioning of the clamps is critical and must be strictly adhered to.

•	Use a solution of soap and water in a spray bottle to pinpoint any suspected air leaks in the induction system and in the charge air cooler assembly.

•	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.

•	Certain types of contaminants on the MAF sensor heating elements act as a heat insulator, which will effect the response of the sensor to airflow changes. This condition will affect the long term fuel trim adaptation value.

•

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 increase or decrease the MAF sensor signal that is interpreted by the ECM. Additionally it may cause a rapid fluctuation in the IAT Sensor parameter.

•	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

•	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.

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

•	Certain aftermarket air filters may cause this DTC to set.

•	Certain aftermarket air induction systems may cause this DTC to set.

•	Modifications to the air induction system may cause this DTC to set.

Reference Information

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Component Connector End Views

Electrical Information Reference

•	Circuit Testing

•	Connector Repairs

•	Testing for Intermittent Conditions and Poor Connections

•	Wiring Repairs

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

Special Tools

EL 38522 Variable Signal Generator

For equivalent regional tools, refer to Special Tools .

Circuit/System Verification

Verify that restrictions do not exist in the exhaust system. Refer to Restricted Exhaust : Diesel .
Verify that an exhaust leak does not exist, including the mating surface area between the turbocharger and the exhaust manifold.
Ignition OFF for 90 s, determine the current vehicle testing altitude.
Ignition ON, engine OFF, observe the scan tool barometric pressure (BARO) parameter, Boost Pressure Sensor parameter, and MAP Sensor parameter. Compare the parameters to the Altitude Versus Barometric Pressure table. The parameters should be within the specified range indicated in the table.
Engine operating at idle, observe the scan tool MAF Sensor parameter. The reading should be between 1 700-3 200 Hz.
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 200 g/s.
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.

Circuit/System Testing

Verify the integrity of the entire air induction system including all turbocharger components by inspecting for the following conditions:

•	Any damaged components

•	Loose or improper installation

•	Water intrusion

•	An air flow restriction

•	Vacuum leaks

•	A turbocharger air leak

•	Improperly routed vacuum hoses

•	In cold climates, inspect for any snow or ice buildup

•	Inspect the MAF sensor elements for contamination

Ignition OFF, disconnect the harness connector at the B75B Mass Air Flow/Intake Air Temperature Sensor.
Ignition OFF for 90 s, test for less than 5 Ω between the ground circuit terminal 2 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 circuit terminal 4 and ground.

⇒	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 F16 is open, test all the components connected to the ignition circuit and replace as necessary.

Test for 4.8-5.2 V between the signal circuit terminal 5 and the ground circuit terminal 2.

⇒	If less than the specified range, test the signal circuit for an open/high resistance or a short to ground. If the circuit/connections test normal, replace the K20 Engine Control Module.

⇒	If greater than the specified range, test the signal circuit for a short to voltage. If the circuit/connections test normal, replace the K20 Engine Control Module.

Ignition OFF, connect the red lead of the EL 38522 generator to the signal circuit terminal 5 at the B75B Mass Air Flow/Intake Air Temperature Sensor harness connector. Connect the battery voltage supply to B+, and ground the black lead.
Set the EL 38522 generator switch to 5 V, the Frequency switch to 5 K, and the Duty Cycle switch to Normal.
Engine Idling, observe the scan tool MAF Sensor frequency parameter. The parameter should be between 4 950-5 025 Hz.

⇒	If the parameter is not within the specified range, replace the K20 Engine Control Module.

If all circuits/connections test normal, replace the B75B Mass Air Flow/ Inlet Air Temperature Sensor.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for ECM replacement, setup, and programming