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Mass air flow sensor

In cold condition vehicle have rpm fluctuation,after 2,3 minute it will be ok.how can i check map sensor,how much the resistance and voltage

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  • Cars & Trucks Master
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Use this test ,see the diagram attached. God bless youmass air flow sensor - c1ce2204-20b3-4718-82d5-9f39642b2d07.jpg

Posted on Jul 24, 2013

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Posted on Jan 02, 2017

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  • 321 Answers

SOURCE: buick lesabre nightmare 2

  • The PCM doesn't even see the O2 sensor until engine temp has reached operating temp,the vehicle goes from open loop when cold,to closed loop when warm,where the PCM uses the O2 sensor to measure the rich/lean of the exhaust content,and from that,adjust fuel richness to achieve 14.7 to 1 air/fuel ratio.So when cold,the O2 sensor is out of the picture anyways.When unplugging sensors,it can be deceitful.The PCM has a program whereas,if a critical sensor (such as the mass air flow) is somehow damaged and out of the picture,the PCM will substitue a generic value that will allow the engine to stay running.So,by unplugging the MAF,it did try to run on it's own better than plugged in,there's the problem area.The vehicle is running better with the MAF unplugged,because the MAF is likely bad,and the PCM is substituting it's generic value when it IS unplugged.Something to recheckThe PROM update is a newer program for the PCM,and likely won't fix it unless the PCM is bad.I would try a good used PCM as a last or later resort,because i have seen my fair share of defective PCM's too.I have taken some PCM's apart,and found capacitors that had gone bad and leaked all over the circuit board,mostly Honda and Mitsubishi and Chrysler though.Good luck,keep me posted.

Posted on Aug 01, 2008

SOURCE: 1999 pontiac grand prix . will not run

If wiggling the wires cured the code, then one of the wires is broken inside the insulation. Pull on each wire one at a time. look for the colored insulation to stretch, this will be the broken wire. For the other car that wont rev up, this is a common when the catalytic concverter is plugged up. This will also cause MAF codes, and in turn, TRAC OFF light.
See http://www.greatautohelp.com

Posted on Oct 17, 2008

  • 1 Answer

SOURCE: 000 NISSAN Xterra -- after warming up, loses RPM by 500-1000..... have replaced ignition wires and distributor, checked mass air flow sensor and OK.....

I had a problem on my Nissan Xterra 2000. Symptons sound similar. In my case, it ran fine for a while and then suddenly the engine starts to stumble and lose output. At one point it did not even have enough HP to move. Irregular idling too. Thought it was water in my fuel. Bought water remover from the store and added to gas tank. Problem did not go away. Instead, "Service Engine Soon" light came on. Had to have it towed to the dealer as there was no way the engine could keep up with traffic. Dealer replaced the "Crank Position Sensor" today. Parts $33.00, Labor: $300 (about 3 hrs worth of work). Seems to work fine now but I will wait and see. Dealer also stated that Distributor bearing appears to be noisy and will need to be replaced sooner or later. I will wait for it to go before I fix that.

Posted on May 27, 2009

  • 95 Answers

SOURCE: 2002 pontiac grand am, idle fluctuates at cold start in parkp0102

Sounds like a vacuum leak. Do you hear a sucking sound? Check your vacuum hoses, around the throttle body and intake for the sound. p0102 can come on when there is unmetered air getting to the engine and it could be fluctuating because the idle air control valve is trying to compensate.

Posted on Sep 27, 2009

lscf150
  • 443 Answers

SOURCE: Engine will not stay running while cold.

Possible, but I would check the coolant temp sensor,EGR valve and it's control sytem components, and then if they check out to be OK I would look towards the ECM(electronic control module)Good luck!

Posted on Nov 22, 2009

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What is causing recurrent DTC P0102?


code p 0102 refers to mass air flow (MAF) sensor/volume air flow(VAF) sensor--low input===causes ---wiring short to ground--MAF/VAF sensor---ecm
check the wiring to the unit--plug connection

Mar 31, 2016 | 1996 Volvo 850

1 Answer

What is a solution to fixing the mass air flow system, with code po121


DTC P0121: Throttle Position (TP) Sensor 1 Performance
Circuit/System Description
The engine control module (ECM) uses the following information to calculate an expected airflow rate:
?€¢
The throttle position (TP)


?€¢
The barometric pressure (BARO)


?€¢
The manifold absolute pressure (MAP)


?€¢
The intake air temperature (IAT)


?€¢
The engine RPM


P0121 The predicted air flow and the predicted MAP combined are outside a calibrated range for more than 3 seconds.
Circuit/System Testing

  1. Inspect for the following conditions:
  2. ?€¢
    Vacuum hoses for splits, kinks, and proper connections as shown on Vehicle Emission Control Information label


    ?€¢
    Inspect thoroughly for any type of leak or restriction


    ?€¢
    Air leaks at throttle body mounting area and intake manifold sealing surfaces


    ?€¢
    Throttle body for dirt, debris, and coking--Refer to Throttle Body Cleaning.

  3. Allow the engine to reach operating temperature. Observe the MAP Sensor Voltage parameter with a scan tool. Voltage should be more than 0.8 volt and less than 4 volts.
  4. ?‡'
    If more than 4 volts or less than 0.8 volt, refer to DTC P0106.

  5. Idle the engine. Observe the MAP Sensor kPa parameter with a scan tool. Increase the engine speed slowly and then back to idle. The MAP sensor kPa should change smoothly and gradually as engine speed is increased and returned to idle.
  6. ?‡'
    If the MAP sensor kPa does not change, refer to DTC P0106.

  7. Take a snapshot of the engine data list while performing the actions listed below. The mass air flow (MAF) sensor g/s should change smoothly and gradually as the engine speed is increased and is returned to idle.
  8. ?€¢
    Idle the engine.


    ?€¢
    Increase the engine speed slowly to 3,000 RPM, then back to idle.


    ?€¢
    Exit from the snapshot and review the data.


    ?€¢
    Observe the Mass Air Flow (MAF) Sensor parameter frame by frame with a scan tool. The MAF sensor g/s should change smoothly and gradually as the engine speed is increased and is returned to idle.


    ?‡'
    If the MAF sensor g/s does not change smoothly and gradually as the engine speed is increased and is returned to idle, refer to DTC P0101 or P1101.

  9. Inspect the throttle body for the following conditions:
?€¢
Loose or damaged throttle blade


?€¢
Broken throttle shaft


?€¢
Any throttle body damage


?‡'
If any of these conditions exist, replace the throttle body assembly.

Jun 20, 2015 | 2008 GMC Sierra 1500 2WD

3 Answers

Engine runs rough and stalls sets a p0068 code on a 05 dodge durango


P0068-MAMFQLD PRESSURE/THROTTLE POSITION CORRELATION
' Image
Theory of Operation
This DTC sets when an unexpected high intake manifold air flow condition exists that
can lead to increased engine speed and puts the NGC into a High Air flow Protection
limiting mode. The High Air flow Protection feature includes RPM limits for when a
Throttle and or MAP sensor limp-in fault is present.
When Monitored
During all drive modes.
Set Condition
If vacuum drops below 1.5Hg with engine RPM greater than 2000 RPM and closed
throttle. One Trip Fault. Three good trips to turn off the MIL.
Possible Causes
-VACUUM LEAK
-RESISTANCE IN THE (FS56) 5-VOLT SUPPLY CIRCUIT
-(FS56) 5-VOLT SUPPLY CIRCUIT SHORTED TO GROUND
-RESISTANCE IN THE (Kl) MAP SIGNAL CIRCUIT
-(Kl) MAP SIGNAL CIRCUIT SHORTED TO GROUND
-RESISTANCE IN THE (FS55) 5-VOLT SUPPLY CIRCUIT
-(FS55) 5-VOLT SUPPLY CIRCUIT SHORTED TO GROUND
-RESISTANCE IN THE (K22) TP SENSOR NO. 1 SIGNAL CIRCUIT
-(K22) TP SENSOR NO. 1 SIGNAL CIRCUIT SHORTED TO GROUND
-RESISTANCE IN THE (K900) SENSOR GROUND CIRCUIT
-MAP SENSOR
-THROTTLE POSITION SENSOR
-PCM
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding.
25312083-mkm0xbqveb5zta3uncrswycs-5-0.png Auto Repair Help US 25312083-mkm0xbqveb5zta3uncrswycs-5-2.jpg

Dec 07, 2014 | Dodge Cars & Trucks

1 Answer

I HAVE HYUNDAI CAR 2002 SHOW HTIS CODE P0106 AND P0172. WHAT IS THE DEFFRENCE BETEEW MAP/BARO, VAF/MAF.


MAP = mass air pressure, Baro is atmospheric air pressure ( as in barometer), VAF = volume air flow and MAF = mass air flow . The baro sensor alters the air fuel mixture for varying altitudes that the vehicle can travel through. IE from flat plains at sea level to over the rockis.. The VAF sensor measures the volume of air passing through the air intake . The MAF measures the combination of volume and the density of the air flowing through the air intake to adjust the air fuel mixture as cold air is more dense and requires more fuel to burn completely. The MAP measures the vacuum in the manifold after the throttle control to adjust the air fuel mixture in over run situations so that the car will not backfire. All these sensors continually supply input to the ECM which continually compares them with the O sensors and adjusts the injector pulse to ensure complete burn of the mixture in all situations and engine rpm's.

May 13, 2014 | Cars & Trucks

1 Answer

Low idle & vibration at idle


I don't know if this will help. Had a similar problem with a 99 Blazer.
Would drop to between 300 and 500 rpm at stop signs and red lights, would stall and shake.
Did all the same checks, replaced mass air flow sensor, replaced cam sensor, cleaned the fuel injectors but the problem was still there.
Replaced both #1 and #2 O2 sensors in the exhaust pipes and now the vehicle runs fine. The idle is back to a steady 750 rpm in all stopping conditions. The Mass air flow sensor and Cam position sensor get information from the O2 sensors.

Apr 10, 2014 | Ford Transit Connect Cars & Trucks

1 Answer

1993 ford ranger 3.0


Replace map sensor

Mar 10, 2013 | Cars & Trucks

1 Answer

2000 nissan sentra 2.0 error codes p0101& p0102


P0102 - Mass Air Flow Sensor Circuit Malfunction

The mass air flownissan-maxima-maf-sensor.jpg or MAF sensor is placed in the intake air duct between the air filter and the engine intake manifold. The MAF sensor measures the amount of intake air flow. The MAF sensor converts the air flow measurement into a voltage or frequency signal, with the voltage or frequency changing proportionally to the amount of air flow. The air flow sensor signal is monitored by the engine computer (ECM). The engine computer (ECM) uses the mass air flow signal to know the engine load and to calculate the proper amount of fuel injected. If the signal from the mass air flow sensor is out of expected range, the ECM detects a fault and sets the code P0100. For example, the mass air flow sensor signal could be higher than expected when the engine is not running or lower than expected with the engine running. A car with the code P0100 may have some driveability issues, such as stalling, lack of power, surging, hesitation, etc. In some cars, the code P0100 can cause the fail-safe mode where the engine speed would be limited to 2,500 - 3,000 rpm.
If there are other trouble codes present, they might need to be looked at first. Checking the freeze frame may help, as it may contain some important information. The freeze frame is a snapshot of the engine parameters at the moment when the fault was detected. The freeze-frame may show whether the vehicle was running or stopped, whether the air-fuel ratio was lean or rich, was the engine was cold or warmed up at the time of the malfunction. Read more about the freeze frame.


Read more about mass air flow sensor.

What could cause the code P0100:
- faulty or contaminated mass air flow sensor
- open or short in the mass air flow sensor electrical circuit
- open or short in the sensor power or ground circuit

- other electrical problem with the MAF sensor wiring, (corroded wires, bent terminals, bad ground connection, burned fuse, etc.
- vacuum leaks
- restricted air flow at or before the air filter
- wrong air flow sensor installed
- problem with ECM





P0102 - Mass Air Flow Sensor Circuit Low

The mass air flow or MAF sensor measures the amount of air entering the engine. The engine computer (ECM) uses the mass air flow signal to calculate the amount of fuel injected (read more how the MAF sensor works below). The code P0102 is set when the signal from the mass air flow sensor is lower than expected. Often a car may exhibit some driveability symptoms, such as lack of power, surging, hesitation on acceleration, hard starting, pinging (detonation), or rough idle when started cold. Often the codes P0171 or P0174 could also be stored along with the code P0102, as the incorrect air flow signal can cause the engine to run lean. The codes P0171 and P0174 indicate a lean condition. Checking the freeze frame might help in the diagnostic process. The freeze frame is stored in the ECM along with the trouble code. The freeze frame contains some recorded parameters (e.g. vehicle speed, engine temperature, fuel trim) at the moment when the fault was detected. The freeze frame can also be accessed with a scan tool.



What could cause the code P0102
- faulty or contaminated mass airflow sensor
- debris blocking the air flow at the mass air flow sensor
- unmetered air leaking past the MAF sensor (vacuum leaks)
- PCV system vacuum leaks
- restricted or collapsed intake air duct
- dirty or restricted air filter
- restricted air screen before the air filter
- improper application of aftermarket components (e.g. cold intake, modified air filter, etc.)
- wrong air flow sensor installed
- electrical problem with the MAF sensor wiring, connector, power supply or ground.
- problem with ECM
- in some cases other issues with the fuel injection system like a clogged catalytic converter or a faulty manifold absolute pressure sensor (MAP) can also cause the code P0102.




Solution for MAF repair

Oct 20, 2012 | 2006 Kia Sorento

1 Answer

Diagnostic Code P2074 on 2007 PT cruiser-can't find on OBD list.


P2074-manifold Pressure/throttle Position Correlation

CORRELATION - HIGH FLOW/VACUUM LEAK

When Monitored: Engine Running, during all drive modes.
Set Condition: If vacuum drops below 1.5 Hg with engine RPM greater than 2000 RPM
at closed throttle.

POSSIBLE CAUSES

VACUUM LEAK
HIGH RESISTANCE IN MAP (K7) 5 VOLT SUPPLY CIRCUIT
RESISTANCE TO GROUND IN MAP (K7) 5 VOLT SUPPLY CIRCUIT
MAP SENSOR
HIGH RESISTANCE IN (K1) MAP SIGNAL CIRCUIT
RESISTANCE TO GROUND IN (K1) MAP SIGNAL CIRCUIT
HIGH RESISTANCE IN (K4) MAP GROUND CIRCUIT
PCM
TP SENSOR OPERATION
HIGH RESISTANCE IN (K6) TP SENSOR 5 VOLT SUPPLY CIRCUIT
RESISTANCE TO GROUND IN (K6) TP SENSOR 5 VOLT SUPPLY CIRCUIT
TP SENSOR
HIGH RESISTANCE IN (K22) TP SIGNAL CIRCUIT
RESISTANCE TO GROUND IN (K22) TP SENSOR SIGNAL CIRCUIT
HIGH RESISTANCE IN TP (K4) SENSOR GROUND CIRCUIT

Mar 27, 2009 | 2007 Chrysler PT Cruiser Touring Hatchback

1 Answer

Po 108 fault code


Sounds more like a mass air flow sensor problem.

Jan 09, 2009 | 2001 Dodge Ram 1500 Truck 2WD

1 Answer

Buick lesabre nightmare 2


  • The PCM doesn't even see the O2 sensor until engine temp has reached operating temp,the vehicle goes from open loop when cold,to closed loop when warm,where the PCM uses the O2 sensor to measure the rich/lean of the exhaust content,and from that,adjust fuel richness to achieve 14.7 to 1 air/fuel ratio.So when cold,the O2 sensor is out of the picture anyways.When unplugging sensors,it can be deceitful.The PCM has a program whereas,if a critical sensor (such as the mass air flow) is somehow damaged and out of the picture,the PCM will substitue a generic value that will allow the engine to stay running.So,by unplugging the MAF,it did try to run on it's own better than plugged in,there's the problem area.The vehicle is running better with the MAF unplugged,because the MAF is likely bad,and the PCM is substituting it's generic value when it IS unplugged.Something to recheckThe PROM update is a newer program for the PCM,and likely won't fix it unless the PCM is bad.I would try a good used PCM as a last or later resort,because i have seen my fair share of defective PCM's too.I have taken some PCM's apart,and found capacitors that had gone bad and leaked all over the circuit board,mostly Honda and Mitsubishi and Chrysler though.Good luck,keep me posted.

Jul 31, 2008 | 1992 Buick LeSabre

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