• | 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 | P0100, P0102 | P0100, P0102 | P0100, P0102 | -- | P0101 |
MAF Sensor Signal High | P0100, P0102 | P0100, P0102 | P0100, P0102 | P0100, P0103 | P0101 |
MAF Sensor Signal Low | -- | P0100, P0103 | P0100, P0103 | -- | P0101 |
Circuit | Short to Ground | Open | Short to Voltage |
---|---|---|---|
Operating Conditions: Engine idling in Closed Loop. Parameter Normal Range: MAF Sensor 1.5-5.0 g/s | |||
Ignition 1 Voltage | 0.40 g/s | 0.40 g/s | -- |
MAF Sensor Signal High | 0.40 g/s | 0.40 g/s | 228 g/s |
MAF Sensor Signal Low | 228 g/s | 228 g/s | * |
* Internal PCM damage may occur if the circuit is shorted to B+. |
The mass air flow (MAF) sensor is an air flow meter that measures the amount of air entering the engine. The control module uses the MAF sensor signal to provide the correct fuel delivery for all engine speeds and loads. The MAF sensor is a hot wire design. A platinum hot wire and a thermistor are located in the intake air bypass passage of the MAF sensor housing. The temperature of the platinum hot wire is affected by exposure to air flow and by exposure to air temperature. The platinum hot wire is maintained at a set temperature by controlling the current flow through the wire. The MAF sensor converts the changes in current flow to a voltage signal. The voltage signal from the MAF sensor enables the PCM to detect changes in air density and changes in air volume.
• | DTCs P0100, P0102, P0103, P0115, P0117, P0118, P0120 P0122, P0123, P0125, P0335, P0340, P0341, P2135 are not set. |
• | The engine is running. |
• | The battery voltage is greater than 10.5 volts. |
• | The engine coolant temperature (ECT) is greater than 75°C (167°F). |
• | DTC P0101 runs continuously when the above conditions are met. |
• | The engine speed is 2,000 RPM or less. |
• | The throttle valve is closed. |
• | The MAF sensor output is greater than 2.2 volts. |
• | The condition is present for greater than 10 seconds. |
OR
• | The engine speed is 300 RPM or more. |
• | The throttle position (TP) sensor input is greater than 0.63 volt. |
• | The MAF sensor output is less than 0.93 volt. |
• | The condition is present for greater than 10 seconds. |
DTC P0101 is a Type B DTC.
DTC P0101 is a Type B DTC.
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Control Module References for scan tool information
• | Objects blocking the MAF sensor inlet |
• | Intake manifold vacuum leaks |
• | Throttle body vacuum leaks |
• | A faulty, missing, or incorrectly installed positive crankcase ventilation (PCV) valve |
• | Vacuum hose splits, kinks, or incorrect connections |
• | Excessive coking or carbon deposits of the throttle valve and throttle bore |
⇒ | If you find any of the above conditions, repair as necessary. |
Important: This test is valid only when the MAF sensor circuits test normal.
• | MAF sensor signal low circuit terminal 2 |
• | MAF sensor signal high circuit terminal 3 |
• | MAF sensor ignition positive voltage circuit terminal 1 |
⇒ | If the signal voltage did not increase with air flow, replace the MAF sensor. |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
• | Control Module References for control module replacement, setup, and programming |