• | 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. |
Circuit | Short to Ground | High Resistance | Open | Short to Voltage | Signal Performance |
---|---|---|---|---|---|
Ignition 1 Voltage | P0031, P0037, P0100, P0458 | P0100 | P0100 | -- | P0100 |
MAF Sensor Signal | P0100 | P0100 | P0100 | P0100 | P0101, P0102, P0103 |
Ground | -- | P0100 | P0100 | -- | P0100 |
Circuit | Short to Ground | Open | Short to Voltage |
---|---|---|---|
Operating Conditions: Engine running at various operating conditions Parameter Normal Range: 1,700-12,500 Hz | |||
Ignition 1 Voltage | 65,535 Hz | 65,535 Hz | -- |
MAF Sensor | 65,535 Hz | 65,535 Hz | 65,535 Hz |
Ground | -- | 65,535 Hz | -- |
The mass air flow (MAF) sensor is integrated with the intake 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 1 voltage |
• | MAF sensor ground |
• | MAF sensor signal |
• | IAT sensor signal |
• | IAT low reference |
The ECM applies 5V to the MAF sensor on the MAF sensor signal circuit. The sensor uses the voltage to produce a frequency based on the inlet air flow through the sensor bore. The frequency varies in a range of near 1,700 Hertz at idle to near 12,500 Hertz at maximum engine load.
• | The engine is running. |
• | The engine speed is greater than 300 RPM. |
• | The ignition 1 voltage signal is greater than 10.5V. |
• | The above conditions are met for greater than 1 second. |
• | This DTC runs continuously within the enabling conditions. |
The ECM detects that the MAF Sensor parameter is equal to 0 Hz for greater than 0.5 second.
The ECM detects that the MAF Sensor parameter is less than 1035 Hz for greater than 0.5 second.
The ECM detects that the MAF Sensor parameter is greater than 15,152 Hz for greater than 0.5 second.
• | DTCs P0100, P0102, P0103 are Type B DTCs. |
• | The ECM will disable boost control and limit the system to mechanical boost only, resulting in a substantial decrease in engine power. |
DTCs P0100, P0102, P0103 are Type B DTCs.
• | The charge air cooler (CAC) is connected to the turbocharger and to the throttle body by flexible ductwork 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 dutctwork, the tightening specifications and proper positioning of the clamps is critical and must be strictly adhered to. |
• | A steady or intermittent high resistance of 15Ω or greater on the ignition 1 voltage circuit will cause the MAF sensor signal to be increased by as much as 60 g/s. |
• | 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. |
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Control Module References for scan tool information
J 38522 Variable Signal Generator
For equivalent regional tools, refer to Special Tools.
• | Loose or improper installation |
• | Water intrusion |
⇒ | If greater than the specified range, test the ground circuit for an open/high resistance. |
⇒ | If the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance. |
⇒ | 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 K20 ECM. |
⇒ | If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the K20 ECM. |
⇒ | If the MAF Sensor parameter is not within the specified range, replace the K20 ECM. |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
• | Control Module References for ECM replacement, setup, and programming |