2003 chevy tracker 2.5 v6 maf sensor voltage, ignition on voltage and running voltage? theres 3 wires one positive, two neg.

Diagnostic Aids
Check for the following conditions:
• A skewed or stuck TP sensor. A problem with the TP sensor or TP sensor circuit can cause the VCM to incorrectly calculate the predicted mass air flow value. Observe the throttle angle with the throttle closed. If the throttle angle reading is not 0%, check for the following conditions:
- The throttle plate is sticking or excessive deposits on the throttle plate or the throttle bore
- The TP sensor signal circuit shorted to voltage
- A poor connection or high resistance in the TP sensor ground circuit.
• A misrouted harness. Inspect the MAF sensor harness in order to ensure that it is not routed too close to high voltage wires such as spark plug leads.
• A damaged harness. Inspect the wiring harness for damage. If the harness appears to be OK, observe the scan tool while moving the connectors and the wiring harnesses related to the MAF sensor. A change in the display indicates the location of the fault.
• A plugged intake air duct or dirty air filter element. A wide open throttle acceleration from a stop should cause the mass air flow displayed on a scan tool to increase from about 4-7 gm/s at idle to 100 gm/s or more at the time of the 1-2 shift. If not, check for a restriction.

Circuit Description
The mass air flow (MAF) sensor is an air flow meter. The control module supplies the MAF sensor a signal circuit. An ignition positive voltage circuit and a ground circuit are supplied to the MAF sensor by independent circuits. The MAF sensor heats a wire element, or grid, within the MAF sensor in order to maintain a calculated temperature. As inlet air flows across and cools the grid, the MAF sensor increases current flow to the grid in order to maintain the constant grid temperature. The MAF sensor converts the grid current flow into a frequency signal. The control module converts the MAF signal frequency into a grams per second value. During low air flow rates, such as at engine idle, the MAF sensor produces a low frequency signal. During high air flow rates, such as at wide open throttle-road load, the MAF sensor increases the frequency signal. The control module monitors the MAF sensor signal frequency in order to calculate the flow and mass of the air entering the engine.
The VCM monitors the MAF sensor air flow rate and compares this signal to a VCM calculated air flow rate. The calculated air flow is based on engine speed and barometric pressure. The VCM uses the MAP sensor in order to determine the barometric pressure when the ignition key is turned ON but before the engine is cranking or running. This DTC will be set if the MAF sensor signal airflow rate does not match the air flow rate calculated by the VCM.

Hi mate start at the easiest point which will be to check your EARTH to make sure everything is earthed.

OBDII DTC

P1001 Key on engine running unable to complete; key on engine running aborted

P1100 Mass air flow sensor intermittent

P1101 Mass air flow sensor out of self test range

P1104 Mass Airflow (MAF) Sensor Ground Circuit Malfunction

P1107 Left MAP Sensor Circuit

P1108 Right MAP Sensor Circuit

P1112 IATS Circuit High Voltage

P1113 IATS Circuit Low Voltage

P1121 Pedal Position Sensor Circuit A Range/Performance

P1122 Pedal Position Sensor Circuit A Low Voltage

P1123 Pedal Position Sensor Circuit A High Voltage

P1137 No Rear HO2S Response

P1138 No Rear HO3S Response

P1157 No Rear HO2S Response

P1158 No Rear HO3S Response

P1171 All Cylinders Too Lean

P1172 All Cylinders Too Rich

P1176 Adaptive Fuel Metering Trim Too Lean

P1177 Adaptive Fuel Metering Trim Too Rich

P1178 Adaptive Fuel Metering Trim Too Lean

P1179 Adaptive Fuel Metering Trim Too Rich

P1187 Both Front HO2S Heater Circuits (High Resistance)

P1188 Both Front HO2S Heater Circuits (Open Short to Ground High Resistance)

P1190 Both Front HO2S Heater Circuits (High Battery Voltage Short to Voltage)

P1193 Both Front HO2S Heater Circuits (High Resistance MAF Sensor Fault)

P1194 Both Front HO2S Heater Circuits (Open Short to Ground High Resistance)

P1196 Both Front HO2S Heater Circuits (High Battery Voltage Short to Ground)

P1198 Fuel Level Sensor (High Voltage)

P1199 Fuel Level Sensor (Low Voltage)

P1201 No. 1 Fuel Injector

P1202 No. 2 Fuel Injector

P1203 No. 3 Fuel Injector

P1204 No. 4 Fuel Injector

P1205 No. 5 Fuel Injector

P1206 No. 6 Fuel Injector

P1221 Pedal Position Sensor Circuit B Range/Performance

P1222 Pedal Position Sensor Circuit B Low Voltage

P1223 Pedal Position Sensor Circuit B High Voltage

P1224 Electronic Throttle Control Position Error

P1226 Mechanical Guard Circuit Range Performance

P1227 Mechanical Guard Circuit Low Input

P1228 Mechanical Guard Circuit High Input

P1229 Throttle Control Circuit Malfunction

P1230 Fuel Pump Relay Malfunction

P1235 VSV 1 Circuit Range/Performance

P1236 VSV 1 Vacuum Circuit Failure

P1237 VSV 2 Atmosphere Circuit Failure

P1238 VSV 3 Release Circuit Failure

P1240 Throttle Position Sensor Voltage Malfunction//Sensor Reference Voltage Low (Throttle

Fuel Tank Pressure)

P1241 Throttle Position Sensor Voltage Low Input//Reference Voltage Low (Throttle Fuel

Tank Pressure)

P1242 Throttle Position Sensor Voltage High Input

P1243 Throttle Position Sensor Ground Malfunction

P1245 Crank Signal Low Input

P1246 Crank Signal High Input

P1313 Misfire Catalyst Damage Bank No. 1

P1314 Misfire Catalyst Damage Bank No. 2

P1315 Misfire Excess Emissions

P1316 Misfire Rate Above Limit

P1335 Crankshaft Position Sensor Circuit

P1336 Camshaft Position Sensor (CMP) Circuit Performance

P1361 Ignition Coil Primary Circuit (Cylinder No. 1)

P1362 Ignition Coil Primary Circuit (Cylinder No. 2)

P1363 Ignition Coil Primary Circuit (Cylinder No. 3)

P1364 Ignition Coil Primary Circuit (Cylinder No. 4)

P1365 Ignition Coil Primary Circuit (Cylinder No. 5)

P1366 Ignition Coil Primary Circuit (Cylinder No. 6)

P1367 Ignition Monitor (Bank A)//Ignition System Failure Group 1

P1368 Ignition Monitor (Bank B)//Ignition System Failure Group 2

P1371 Early Activation Ignition Coil (Cylinder No. 1)

P1372 Early Activation Ignition Coil (Cylinder No. 2)

P1373 Early Activation Ignition Coil (Cylinder No. 3)

P1374 Early Activation Ignition Coil (Cylinder No. 4)

P1375 Early Activation Ignition Coil (Cylinder No. 5)

P1376 Early Activation Ignition Coil (Cylinder No. 6)

P1392 Variable Valve Timing Solenoid A Low Input

P1393 Variable Valve Timing Solenoid A High Input

P1396 Variable Valve Timing Solenoid B Malfunction

P1397 Variable Valve Timing Solenoid B Low Input

P1398 Variable Valve Timing Solenoid B High Input

P1400 EGR Valve Position Circuit (Valve Sticking Open or Short)

P1401 EGR Valve Position Circuit (Open Short to Ground)

P1408 EGR Temperature Sensor Circuit

P1409 EGR Valve Circuit

P1440 EVAP Purge Valve Open

P1441 EVAP Valve Circuit

P1443 EVAP Valve Circuit

P1447 EVAP Valve Circuit

P1448 EVAP Valve Circuit

P1454 EVAP System

P1474 Charge Air Coolant Pump Relay

P1475 Radiator Fans Slow Malfunction

P1476 Radiator Fans Fast Parallel Circuit Malfunction

P1506 Idle Speed Control Circuit (Low RPM; Bank B)

P1507 Idle Speed Control Circuit (High RPM; Bank B)

P1508 Idle Speed Control Circuit

P1509 Idle Speed Control Circuit

P1512 Throttle Position Sensor Idle Switch Sense Circuit

P1513 Throttle Position Sensor Idle Switch Sense Circuit

P1514 Park/Neutral Position Switch High Load Neutral/Drive

P1516 Gear Change Park/Neutral Malfunction

P1517 Engine Cranking Park/Neutral Malfunction

P1607 MIL Output Circuit

P1608 Automatic Transmission

P1609 Internal ECM Error

P1641 Fuel Pump Relay No. 1

P1646 Fuel Pump Relay No. 2

P1739 Automatic Transmission

P1775 Transmission Control Module MIL Circuit

P1776 Torque Reduction Request Signal

P1777 Torque Reduction Circuit

P1780 Automatic Transmission

P1781 Automatic Transmission

P1782 Automatic Transmission

P1783 Automatic Transmission

P1785 Automatic Transmission

P1790 Automatic Transmission

P1791 Automatic Transmission

P1792 Automatic Transmission
P1794 Automatic Transmission

V6 - Tracker (2003, for example) - CKP sensor low in FRONT of engine behind Harmonic Balancer. 1-2 hrs. work, not 7.

Use a voltmeter to check the DC voltage to the maf by probing the back of the connector on the pink and black wires. Have someone start the car while you watch the meter. It should show the alternator voltage of 13.5-14.5 vdc, and it should stay constant. Watch it until the engine dies. If the car passes this test, switch from the pink wire to the yellow wire and do the same thing. The voltage on the yellow wire will be lower, but it should not change much until the engine dies.
If the car fails either of these tests, there is some problem with the wiring.
If the car passes these tests, the circuit is probably ok.
That means something is probably blocking airflow. Remove the air filter and look/feel upstream. Check the inlet duct on the front of the car for blockage. Maybe a plastic bag got stuck in there...

the mass air flow is part of the throttle body assembly. its where the big air hose from the air filter hooks to on the motor. here is a picture to aid you. hope this helps

The mass air flow (MAF) sensor is an integral part of the throttle body assembly and cannot be serviced separately. For replacement of the MAF sensor refer to Throttle Body Assembly Replacement.

You can test the MAF before replacing. It may be a problem with the circuit itself or just a fluke from another problem that is connected to this sensor.

There are two basic types of mass airflow sensors: hot wire and hot film. In the first type, a very thin wire (about 0.2 mm thick) is used as the heated element.
Components of a hot wire-type mass airflow sensor. Courtesy of Ford Motor Company. The element temperature is set at 100° to 200°C above incoming air temperature. Each time the ignition switch is turned to the off position, the wire is heated to approximately 1,000°C for 1 second to burn off any accumulated dust and contaminants.
The second type uses a nickel foil sensor, which is kept 75°C above ambient air temperatures. It does not require a burn-off period and therefore is potentially longer lasting than the hot wire type.
A faulty MAF will cause driveability problems resulting from incorrect ignition timing and improper air/fuel ratios.
Vane-type MAF Sensors
A vane-type MAF sensor is found on many import and domestic vehicles with EFI. All intake air must flow through the sensor. Some MAF sensors are called volume air flow meters

• Begin checking a vane-type MAF sensor by checking the voltage supply wire and the ground wire to the MAF module before checking the sensor voltage signal.
• Always follow the recommended test procedure in the manufacturer's service manual and use the specifications supplied by the manufacturer.
• Typically, to test the sensor, a digital multimeter (DMM) is used and set on a DC voltage scale. The negative meter lead is connected to ground and the red lead to the MAF signal wire.

A voltmeter connected to measure the signal from a MAF sensor. Reproduced with permission from Fluke Corporation.

• Turn on the ignition switch and press the min/max button, if available, on the DMM.
• Slowly push the MAF vane from the closed to the wide-open position, and allow the vane to slowly return to the closed position.

Move the MAF sensor air vane from open to close to test it. Reproduced with permission from Fluke Corporation.

• Observe the maximum and minimum voltage readings as the vane was moved.
• If the minimum voltage signal is zero, there may be an open circuit in the MAF sensor variable resistor.
• When the voltage signal is not within the manufacturer's specifications, replace the sensor.

WARNING While pushing the mass air flow sensor vane open and closed, be careful not to mark or damage the vane or sensor housing.

• Some vehicle manufacturers specify ohmmeter tests for the MAF sensor.
• With the MAF sensor removed, connect the ohmmeter across the sensor's output and input terminals.

Ohmmeter connections to a MAF sensor. Reprinted with permission.

• The resistance at these terminals is normally 200 to 600 ohms.
• Connect the ohmmeter leads to the specified MAF sensor terminals, and move the vane from the fully closed to the fully open position.
• With each specified meter connection and vane position, the ohmmeter should indicate the specified resistance.

Resistance specifications for a typical MAF sensor with door open and closed. Reprinted with permission.

• When the ohmmeter leads are connected to the sensor's input and output terminals, the ohmmeter reading should increase smoothly as the sensor vane is opened and closed.
• To check a vane-type MAF with a lab scope, connect the positive lead to the output signal terminal and the negative scope lead to a good ground.
• This type MAF should display an analog voltage signal when the engine is accelerated. A defective MAF will have sudden and erratic voltage changes.

The trace of a defective vane-type MAF sensor. Reproduced with permission from Fluke Corporation. Hot-Wire-Type MAF Sensors
The test procedure for heated resistor and hot-wire MAF sensors varies depending on the vehicle make and year. Always follow the test procedure in the appropriate service manual. A frequency test may be performed on some MAF sensors, such as the AC Delco MAF on some General Motors' products.

• To check the MAF sensor's voltage signal and frequency, connect a voltmeter across the MAF voltage signal wire and ground wire.
• Start the engine and observe the voltmeter reading.
• On some MAF sensors, this reading should be 2.5 volts.
• Lightly tap the MAF sensor housing with a screwdriver handle and watch the voltmeter pointer.
• If the pointer fluctuates or the engine misfires, replace the MAF sensor.
• Some MAF sensors have experienced loose internal connections, which cause erratic voltage signals and engine misfiring and surging.
• Set the DMM so that it can read the frequency of DC voltage.
• With it still connected to the signal wire and ground, the meter should read about 30 Hz with the engine idling.
• Now, increase the engine speed, and record the meter reading at various speeds.
• Graph the frequency readings. The MAF sensor frequency should increase smoothly and gradually in relation to engine speed.
• If the MAF sensor frequency reading is erratic, replace the sensor.

Satisfactory and unsatisfactory MAF sensor frequency readings. Reproduced with permission from Fluke Corporation.

• When a scanner is used to diagnose a General Motors' vehicle, one test mode displays grams per second from the MAF sensor. This mode provides an accurate test of the MAF sensor.
• The grams per second reading should be 4 to 7 with the engine idling.
• This reading should gradually increase as the engine speed increases.
• When the engine speed is constant, the grams-per-second reading should remain constant.
• If the grams-per-second reading is erratic at a constant engine speed or if this reading varies when the sensor is tapped lightly, the sensor is defective.
• A MAF sensor fault code may not be present with an erratic grams-per-second reading, but the erratic reading indicates a defective sensor.
• Frequency-varying types of MAF sensors can be tested with a lab scope.
• The waveform should appear as a series of square waves.

A normal trace for a frequency-varying MAF sensor. Courtesy of Progressive Diagnostics--WaveFile AutoPro.

• When the engine speed and intake air flow increases, the frequency of the MAF sensor signals should increase smoothly and proportionately to the change in engine speed.
• If the MAF or connecting wires is defective, the trace will show an erratic change in frequency.

The trace of a defective frequency-varying MAF sensor. Courtesy of EDGE Diagnostics Systems.

There is also a
Mass Air Flow (MAF) Burn-Off Module Operation:
A semi-conductor control for an electronic-ignition system.

disconnect the neg batt cable,loosen clamp and disconnect air cleaner outlet tube and resonator from the air cleaner. 2.disconnect maf sensor connector. 3.lift air cleaner assy from tray and position aside. 4. remove screws from power steering resevoir, and position aside. 5.disconnect brake fluid level sensor, and if equiped brake pressure switch. 6.remove the two mounting nuts holding master cylinder, position master cylinder aside (DO NOT LOOSEN LINES ON MASTER CYL). 7.remove mounting bolts for degas bottle and postion aside. 8.if equiped diconnect wiring at the pedal position sensor. 9.relaease clamp and disconnect hose. 10.remove the pin, washer, bushing and switch, disconnect pushrod. 11.remove the nuts and brake booster, to access nuts fold back sound insulation. reverse procedure to install.

fuel pressure regulator, or the computer needs reset!!