2010 Cadillac Truck SRX FWD V6-3.0L Page 1112

2010 Cadillac Truck SRX FWD V6-3.0L Page 1112

Instructions) provides an overview of each diagnostic category.

DTC Descriptor

DTC P0101

- Mass Air Flow (MAF) Sensor Performance

Diagnostic Fault Information

Typical Scan Tool Data

Circuit Description

The intake flow rationality diagnostic provides the within-range rationality check for the mass air flow (MAF), manifold absolute pressure (MAP),

and the throttle position sensors. This is an explicit model-based diagnostic containing 4 separate models for the intake system.

* The throttle model describes the flow through the throttle body and is used to estimate the MAF through the throttle body as a function of

barometric pressure (BARO), throttle position sensors, intake air temperature (IAT), and estimated MAP. The information from this model is

displayed on the scan tool as the MAF Performance Test parameter.

* The first intake manifold model describes the intake manifold and is used to estimate MAP as a function of the MAF into the manifold from

the throttle body and the MAF out of the manifold caused by engine pumping. The flow into the manifold from the throttle uses the MAF

estimate calculated from the above throttle model. The information from this model is displayed on the scan tool as the MAP Performance

Test 1 parameter.

* The second intake manifold model is identical to the first intake manifold model except that the MAF sensor measurement is used instead of

the throttle model estimate for the throttle air input. The information from this model is displayed on the scan tool as the MAP Performance

Test 2 parameter.

* The fourth model is created from the combination and additional calculations of the throttle model and the first intake manifold model. The

information from this model is displayed on the scan tool as the Throttle Position Sensors Performance Test parameter.

The estimates of MAF and MAP obtained from this system of models and calculations are then compared to the actual measured values from the

MAF, MAP, and the throttle position 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.