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• | 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 Voltage | P0102, P121B | P0101, P0102 | P0102 | P0690 | P0101 |
MAF Sensor Signal | P0102 | P0102 | P0101, P0102 | P0102 | P0101, P1101 |
MAF Control | P0101, P121B | P0101, P0102 | P0101, P0102 | P0101, P0102, P121C | - |
Circuit | Short to Ground | Open | Short to Voltage |
---|---|---|---|
Operating Conditions: Vehicle ON, normal operating temperature and engine speed between 1,375 and 1,425 RPM Parameter Normal Range: 1,800-2,400 Hz | |||
Ignition Voltage | 0 Hz | 0 Hz | - |
MAF Sensor Signal | 0 Hz | 0 Hz | 0 Hz |
MAF Control | - | 0 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 air flow and engine speed are very dependent on the battery pack state of charge. A small quantity of air entering the engine indicates a low load condition. A large quantity of air entering the engine indicates a high load condition.
The ECM applies 5 volts 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 MAF sensor is supplied power through the powertrain relay and a fuse. The ECM enables the MAF sensor only during engine run mode by grounding the MAF control circuit via a solid state devise called a driver. The driver is equipped with a feedback circuit that is pulled-up to a voltage. The ECM monitors the status of the driver. If the ECM detects an incorrect voltage for the commanded state of the driver, a MAF sensor supply voltage low side driver control circuit DTC is set.
• | DTCs P0102, P0103, P0107, P0108, P0111, P0112, P0113, P0114, P0116, P0117, P0118, P0119, P0128, P0335, and P0336 are not set. |
• | The engine speed is between 500 and 8,000 RPM. |
• | The IAT Sensor is between -20 and +125°C (-4 and +257°F). |
• | The ECT Sensor is between -7 and +125°C (+19 and +257°F). |
• | The DTC runs continuously when the above conditions are met. |
The ECM detects that the MAF sensor signal is not within a predetermined range of the calculated MAF value.
DTC P0101 is a Type B DTC.
DTC P0101 is a Type B DTC.
• | Inspect the harness of the MAF sensor to verify that it is not routed too close to the following components: |
- | The ignition coil module |
- | Any solenoids |
- | Any relays |
- | Any motors |
• | Any type of contamination on the MAF sensor heating elements will degrade the proper operation of the sensor. Certain types of contaminants act as a heat insulator, which will impair the response of the sensor to airflow changes. Water or snow can create the opposite effect, and cause the signal to increase rapidly. 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. |
Hybrid Modes of Operation Description
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 : Diagnostic Tools .
Note: To ensure a proper engine load, this diagnostic should be performed when the Hybrid/EV Battery Pack Charge Remaning parameter is at least 40%.
⇒ | If any of the DTCs are set, refer to DTC P121B or P121C . |
• | A dirty, restricted, or deteriorating air filter element |
• | A leaking, loose, or cracked PCV pipe or seal |
• | A restricted or collapsed air inlet duct |
• | A misaligned, leaking, or damaged air inlet duct |
• | Any objects blocking the air inlet probe of the B75B mass air flow/inlet air temperature sensor |
• | Any contamination or debris on the sensing elements in the probe of the B75B mass air flow/inlet air temperature sensor |
• | A cracked, damaged, or leaking B75B mass air flow/inlet air temperature sensor housing |
• | Any water intrusion in the induction system |
• | Any snow or ice build-up at the air cleaner or B75B mass air flow/inlet air temperature sensor in cold climates |
• | Any vacuum leak |
• | A B74 MAP sensor seal that is leaking, missing, or damaged |
• | Q38 Throttle body for dirt, debris, and coking. Refer to Throttle Body Inspection and Cleaning . |
• | A damaged Q38 throttle body blade or shaft |
• | Missing, restricted, or leaking exhaust components. Refer to Symptoms - Engine Exhaust . |
⇒ | If you find any of the above conditions, repair as necessary. |
⇒ | 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 test lamp does not illuminate, test the ignition voltage circuit for a short to ground or an open/high resistance. If the circuit tests normal and the ignition voltage circuit fuse is open, test or replace the components on the ignition voltage circuit. |
⇒ | If the test lamp is always ON, test the control circuit for a short to ground. If the circuit tests normal, replace the K20 ECM. |
⇒ | If the test lamp is always OFF, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the K20 ECM. |
• | Signal switch to 5 V |
• | Frequency switch to 5 KHz |
• | Duty Cycle switch to Normal |
Note: The engine may run rough and stall.
⇒ | If 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 |
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