Important: The following applies to the intake airflow system performance diagnostic that is used in this supercharged engine:

The intake airflow system performance diagnostic provides the within-range rationality check for the mass air flow (MAF), supercharger inlet absolute pressure (SCIP), MAP, by-pass valve stuck, and the throttle position (TP) sensors. This is an explicit model-based diagnostic containing 4 separate models for the intake system.

The estimates of MAF, SCIP, and TP that are obtained from this system of models and calculations are then compared to the actual measured values from the MAF, SCIP, and the TP sensors and to each other to determine the appropriate DTC to fail. The following table illustrates the possible failure combinations and the resulting DTC or DTCs.

The engine control module (ECM) detects that the actual measured intake system parameters from the MAF, MAP, SC Inlet Pressure, and the TP sensors are not within a range of the corresponding calculated parameters that are derived from the system of models by greater than a calibrated threshold for greater than 10 seconds.

DTCs P1101 is a Type B DTC.

DTCs P1101 is a Type B DTC.

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Electrical Information Reference

Scan Tool Reference

DTC Type Reference

Special Tools Required

J 38522 Variable Signal Generator

Inspect for the following conditions that may set this DTC:

Caution: Refer to Road Test Caution in the Preface section.

1. Verify the integrity of the entire supercharger air induction system by inspecting for the following conditions:

•	A restricted or collapsed air intake duct

•	A misaligned or damaged air intake duct

•	A dirty or deteriorating air filter element

•	Any objects blocking the air inlet probe of the MAF/IAT sensor

•	Any contamination or debris on the sensing elements in the probe of the MAF/IAT sensor

•	Any water intrusion in the induction system

•	Any vacuum leak downstream of the MAF/IAT sensor

•	An intake manifold leak

•	A SCIP sensor vacuum hose that is missing or damaged

•	A MAP sensor vacuum hose that is missing or damaged

•	A BARO sensor that is skewed or stuck

•	A skewed or stuck ECT or IAT sensor--Refer to Temperature Versus Resistance .

•	Any type of restriction in the exhaust system--Refer to Restricted Exhaust .

2. Inspect the by-pass valve and cable for any of the following conditions:

•	Sticking in either the open or closed position

•	Binding when opening or closing

•	Incorrectly adjusted cable

•	Any damage

⇒	If any of the above conditions are found, refer to Supercharger Cleaning and Inspection .

3. Ignition ON, observe the MAP and SC Inlet Pressure Sensor kPa parameters with a scan tool. Start the engine and let it idle. The MAP and SC Inlet Pressure Sensor kPa parameters should decrease and closely match each other.

⇒	If the MAP Sensor kPa parameter does not decrease, refer to DTC P0106 .

⇒	If the SC Inlet Pressure kPa parameter does not decrease, refer to DTC P1182.

4. Ignition ON, depress the accelerator pedal completely and observe the TP Indicated Angle parameter with a scan tool. The TP Indicated Angle parameter should read 98-100 percent.

⇒	If the TP Indicated Angle parameter is not within the specified range, refer to DTC P1516, P2101, P2119, or P2176 .

5. With the ignition ON and the engine OFF, perform a snapshot of the throttle actuator control (TAC) data while performing the following action. Refer to Scan Tool Snapshot Procedure .

5.1.	Slowly depress the accelerator pedal to WOT position and then slowly release the pedal. Exit from the snapshot and review the data.

5.2.	Compare the TP Sensor 1 and the TP Sensor 2 parameters, frame by frame. The difference between the parameters should be less than 4 percent.

⇒	If the TP Sensor 1 and Sensor 2 parameter difference is more than 4 percent, refer to DTC P0120, P0122, P0123, P0220, P0222, P0223, or P2135 .

Caution: Refer to Road Test Caution in the Preface section.

6. Engine running, on a road test perform a brief wide open throttle (WOT) acceleration from 30 mph. The MAP sensor parameter on the scan tool should increase rapidly. This increase should be from approximately 35 kPa at idle to greater than 135 kPa.

⇒	If the MAP Sensor parameter does not increase to greater than the specified range, refer to Boost Control System Diagnosis .

1. Ignition OFF, disconnect the harness connector at the MAF sensor.
2. Ignition OFF, test for less than 5 ohms of resistance between the ground circuit terminal B and ground.

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

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

⇒	If less than the specified range, test the MAF sensor signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the ECM.

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

4. Ignition ON, verify that a test lamp illuminates between the MAF sensor ignition 1 voltage circuit terminal C and ground.

⇒	If the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance.

5. Connect the J 38522 to the vehicle. Refer to Component Testing.

To determine if the ECM can properly process the MAF sensor frequency signal, connect the J 38522 to the vehicle as follows:

1. Turn OFF the ignition.
2. Connect the battery voltage supply and ground the black lead.
3. Connect the red lead to the signal circuit terminal A of the MAF sensor.
4. Set the duty cycle switch to Normal.
5. Set the Frequency switch to 5 K.
6. Set the signal switch to 5 volts.
7. Start the engine, observe the MAF Sensor parameter for the correct range of 4,950-5,025 Hz.

⇒	If the MAF Sensor parameter is not within the specified range, replace the ECM.

⇒	If the MAF Sensor parameter is within the specified range, replace the MAF sensor.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.