Tip & How-To about Mazda Protege

How to test a MAF and Map sensor and CTS (coolant temp sensor)

I have used this technic for a MAF sensor with three wires on it. Two of the wires would be power and ground and the third smaller wire would be the output signal going to the computer. Here is the procedure. First you have to have a digital multimeter. Turn the ignition to on position. Then measure the output voltage from the MAF sensor as you blow air into the filament. You should be able to see changes in voltages of a few volts. Almost the same procedure when testing a map sensor, except on the map sensor you apply slight vacuum to the hose connector.
To test coolant temperature sensor, measure the resistance at the terminal. On a cold engine the resistance should be a few thousand ohms. Then measure the resistance again when the engine is hot which should be a few hundred ohms. You are not looking here for exact reading but rather look for a drastic change in value. A bad temperature sensor will either change very little in resistance value or not change at all related to temperature difference.

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Checked for other codes the only thing that comes up is the maf not detecting any data from the mass air flow sensor. What are the possibilities of getting a bad sensor, I did bought a remanufactured or how about the pig tail? Is there a possibility for broken wires? Or a bad sensor how can a person find this out? Don't want to take to a dealer and pay big bucks for nothing


I hear that. Okay, it's a MAF sensor, here's how one on a buick century (2005) works: from a fuse in the power distribution box, power is sent to the maf sensor when the ignition key is on. There is also a ground wire, and then there is a third wire, the signal wire to the pcm. If no data from sensor, first check the power and ground to the sensor. A voltmeter, one lead in the power terminal at the pigtail (disconnected), and the other lead on the ground terminal-with key on, you should see 12 volts or close to it. If so the power and ground is good for the sensor. If no volts show on the voltmeter, keep the positive lead of voltmeter on the power wire terminal at the pigtail, and move the negative lead of voltmeter to the negative post of the battery. If still no 12 volts at the pigtail, the sensor is not getting a reference voltage: either the fuse is blown or a short in the wire from the power distribution box to the sensor.
(Now some sensors use a 5 volt reference signal, and this would come from the pcm itself: so look for a voltage at the sensor-it will either be about 5 volts, or about battery voltage.)
If moving negative lead of voltmeter (or testlight if no voltmeter) to the negative post of battery causes voltage now-then the ground wire for the sensor is bad.
If the power (the reference signal) and the ground to the sensor is good, but no data? Then you have to suspect the sensor is bad or the signal wire to the pcm may have a break. Then you have to pull the connectors off at the pcm (disconnect the battery first) and find the pin-out number for the maf sensor signal wire. If the wires are visible at the pcm, try matching wire colors to find the correct pin number. Now you can check the continuity of the maf signal wire from the pigtail to the pcm connector (easy on an '05 buick: the pcm is under the hood very close to the maf sensor). Set the voltmeter to ohms, one lead on the pigtail at the signal wire, the other on the pcm connector at the terminal where the maf signal comes in. For the little tiny pin terminals on the pcm connectors, use a paper clip stuck in the slot, if you need to. You should see low resistance to current flow- a very low ohms value, maybe just a fraction of an ohm. That tells you the wire is good, has good continuity-it ain't broke.
Yup, you just better invest in a digital volt/ohm meter (DVOM), if you don't already have one-it will save you big bucks from the stealerships. I use a craftsman meter from sears-about $40, and it's over 10 years old.

Jun 24, 2014 | Cars & Trucks

1 Answer

transmission in failsafe code p0108andp0104andp0102andp0101andp0110


P0108 - (Manifold Absolute Pressure/Barometric Pressure Circuit High Input
The MAP (Manifold Absolute Pressure) sensor measures engine manifold negative air pressure. It's usually a three wire sensor: a ground wire, a 5 volt reference wire from the PCM (Powertrain Control Module) to the MAP sensor, and a signal wire that informs the PCM of the MAP sensor voltage reading as it changes. The higher the engine vacuum, the lower the voltage reading. The voltage should range between about 1 volt (at idle) to about 5 volts (WOT wide open throttle).

If the PCM sees the voltage reading from the MAP sensor is greater than 5 Volts, or if the voltage reading is higher than what the PCM considers normal under certain circumstances, a P0108 DTC will set.

Symptoms of a P0108 DTC code may include:
* MIL (Malfunction Indicator Lamp) will likely be on
* Engine may run poorly
* Engine may not run at all
* Fuel mileage may decrease
* Presence of black smoke at exhaust

Potential causes of a P0108 code:
* Bad MAP sensor
* Leak in vacuum supply line to MAP sensor
* Engine vacuum leak
* Short on signal wire to PCM
* Short on reference voltage wire from PCM
* Open in ground circuit to MAP
* Worn engine causing low vacuum

Possible Solutions:
A good way to diagnose if the MAP sensor is to blame would be to compare the KOEO (key on engine off) MAP sensor reading on a scan tool with the Barometric pressure reading. They should be the same because they both measure atmospheric pressure.

If the MAP reading is greater than 0.5 volt off of the BARO reading, then replacing the MAP sensor would likely fix the problem. Otherwise, start the engine and observe the MAP reading at idle. It should normally be about 1.5 volts (varies according to altitude).

a. If it is, the problem is likely intermittent. Check all the vacuum hoses for damage and replace as necessary. You can also try wiggle testing the harness and connector to reproduce the problem.
b. If the scan tool MAP reading is more than 4.5 volts, check the actual engine vacuum reading with the engine running. If it is less than 15 or 16 in. Hg, then the PCM is probably not seeing enough vacuum (due to a worn engine, perhaps) for a given operating condition (which causes a higher than normal voltage signal to the PCM) and setting the code. Repair the engine vacuum problem and retest.
c. But, if the actual engine vacuum reading is 16 in. Hg or more, then unplug the MAP sensor. The scan tool MAP reading should indicate that there is no voltage present. Check that the ground from the PCM is intact and also that the MAP sensor connector and terminals are tight. If the connection is good, then replace the map sensor.
d. However if, with KOEO, & the MAP sensor unplugged, the scan tool shows a voltage reading, then there may be a short in the harness to the MAP sensor. Turn the ignition off. At the PCM unplug connector and remove the MAP signal wire from the connector. Re-attach the PCM connector and see if with KOEO, the scan tool MAP reading shows voltage. If it still does, replace the PCM. If not, check for voltage on the signal wire you just removed from the PCM. If there is voltage on the signal wire, find the short in the harness and repair.


P0104 - Mass Air Flow (MAF) Circuit Intermittent
Basically this means that there is a problem with the Mass Air Flow High (MAF) sensor or circuit. A more technical description would be that the MAF is producing incorrect air flow readings. Other MAF sensor circuit DTC trouble codes are P0100, P0101, P0102, and P0103.

Symptoms: You will likely not notice any serious drivability problems, although there may be symptoms such as a general decrease in power or sluggishness.

Causes: A code P0104 may mean that one or more of the following has happened:
* The mass air flow (MAF) circuit is incomplete (broken / frayed wire, etc.)
* There is an air leak in the intake system

Possible Solutions: The simplest thing to do is to reset the code and see if it comes back. Then start with the cheapest, easiest repair procedures:
* Verify that the Mass Air Flow Sensor wiring is connected properly and that there are no broken / frayed wires.
* Inspect for any air leaks near the MAF sensor.
* Check the voltage of the MAF sensor (refer to a repair manual for vehicle specific information)
* Replace the MAF sensor.



P0102 - Mass Air Flow (MAF) Circuit Low Input
Basically this means that there is a problem with the Mass Air Flow (MAF) sensor or circuit. A more technical description would be that the MAF circuit had lower than expected voltage (air flow). Other MAF sensor circuit DTC trouble codes are P0100, P0101, P0103, and P0104.
Symptoms: You will likely not notice any serious drivability problems, although there may be symptoms such as a general decrease in power or sluggishness.

Causes: A code P0102 may mean that one or more of the following has happened:
* The MAF may be disconnected, or a wiring connection may be bad
* The MAF may be dirty or otherwise contaminated (Note: if you use a reusable oiled air filter, be careful not to apply too much oil or that can contaminate the MAF).
* The MAF sensor may be faulty
* The vehicle computer may be faulty (very rare)

Possible Solutions: The simplest thing to do is to reset the code and see if it comes back. Then start with the cheapest, easiest repair procedures:
* Verify that the Mass Air Flow Sensor wiring is connected properly and that there are no broken / frayed wires.
* Inspect for any air leaks near the MAF sensor.
* Take the MAF out and clean it using a spray cleaner such as brake cleaner or electrical contact cleaner. Be gentle with the sensor.
* Check the voltage of the MAF sensor (refer to a repair manual for vehicle specific information)
* Replace the MAF sensor.




P0101 - Mass Air Flow (MAF) Circuit Range/Performance Problem
Basically this means that there is a problem with the Mass Air Flow (MAF) sensor or circuit. The PCM detects that the actual MAF sensor frequency signal is not within a predetermined range of the calculated MAF value for more than 4.0 seconds. Other MAF sensor circuit DTC trouble codes are P0100, P0102, P0103, and P0104.

Symptoms: You will likely not notice any serious drivability problems, although there may be symptoms.

Possible Solutions: The simplest thing to do is to reset the code and see if it comes back. Then start with the cheapest, easiest repair procedures:
* Inspect for the following conditions:
An incorrectly routed harness--Inspect the harness of the MAF sensor in order to verify that it is not routed too close to the following components:
- The secondary ignition wires or coils
- Any solenoids
- Any relays
- Any motors
* A low minimum air rate through the sensor bore may cause this DTC to set at idle or during deceleration. Inspect for any vacuum leaks downstream of the MAF sensor.
* A wide open throttle (WOT) acceleration from a stop should cause the MAF sensor g/s display on the scan tool to increase rapidly. This increase should be from 6-12 g/s at idle to 230 g/s or more at the time of the 1-2 shift. If the increase is not observed, inspect for a restriction in the induction system or the exhaust system.
* The barometric pressure (BARO) that is used in order to calculate the predicted MAF value is initially based on the MAP sensor at key ON.
* When the engine is running the MAP sensor value is continually updated near WOT. A skewed MAP sensor will cause the calculated MAF value to be inaccurate. The value shown for the MAP sensor display varies with the altitude. With the ignition ON and the engine OFF, 103 kPa is the approximate value near sea level. This value will decrease by approximately 3 kPa for every 305 meters (1,000 feet) of altitude.
* A high resistance on the ground circuit of the MAP sensor can cause this DTC to set.
* Any loss of vacuum to the MAP sensor can cause this DTC to set.

If you suspect the condition may be related to aftermarket accessories, refer to Checking Aftermarket Accessories in Wiring Systems. Here as an aid in resolving your P0101 trouble code (DTC)...

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Jan 20, 2011 | 2002 Jaguar X-Type

1 Answer

P0100 MAF or VAF A ckt Malfuction. What can we check to solve the problem Montero Sport V6 3 liter


P0100 OBD-II Trouble Code

Technical Description

Mass Air Flow (MAF) Circuit Malfunction

Basically this means that there's a problem with the Mass Air Flow (MAF) sensor or circuit.

You will likely not notice any serious driving problems, but there may be symptoms like a general decrease in power or sluggishness.
Causes

A code P0100 may mean one or more of the following:

* The MAF may be disconnected, or a wiring connection may be bad.
* The MAF sensor may be faulty.

Possible Solutions

Use an OBD II Reader (or go tou your local parts store and they will for free) and reset the code and see if it comes back.
Then start with the cheapest, easiest repair procedures:

* Check the Mass Air Flow Sensor wiring/harness is connected properly and that there are no broken / frayed wires.
* Unplug and reconnect the MAF wiring harness a few times to clear the contacts.
* Check the voltage of the MAF sensor (refer to a repair manual for vehicle specific information).
* Replace the MAF sensor.

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Sep 01, 2010 | 1999 Mitsubishi Montero Sport

1 Answer

Received a P0136 code error and replaced 02 sensor #2, now vehicle will not start and now showing a P0100 & P0505 code.


P0100 OBD-II Trouble Code

Technical Description

Mass Air Flow (MAF) Circuit Malfunction

Basically this means that there's a problem with the Mass Air Flow (MAF) sensor or circuit.

You will likely not notice any serious driving problems, but there may be symptoms like a general decrease in power or sluggishness.
Causes

A code P0100 may mean one or more of the following:

* The MAF may be disconnected, or a wiring connection may be bad.
* The MAF sensor may be faulty.

Possible Solutions

Use an OBD II Reader (or go tou your local parts store and they will for free) and reset the code and see if it comes back.
Then start with the cheapest, easiest repair procedures:

* Check the Mass Air Flow Sensor wiring/harness is connected properly and that there are no broken / frayed wires.
* Unplug and reconnect the MAF wiring harness a few times to clear the contacts.
* Check the voltage of the MAF sensor (refer to a repair manual for vehicle specific information).
* Replace the MAF sensor.

Thanks for using FixYa - a 4 THUMBS rating is appreciated for answering your FREE question.
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Jun 02, 2010 | 1996 Mitsubishi Galant

1 Answer

maf sensor code p0100-128


P0100 OBD-II Trouble Code

Technical Description

Mass Air Flow (MAF) Circuit Malfunction

Basically this means that there's a problem with the Mass Air Flow (MAF) sensor or circuit.

You will likely not notice any serious driving problems, but there may be symptoms like a general decrease in power or sluggishness.
Causes

A code P0100 may mean one or more of the following:

* The MAF may be disconnected, or a wiring connection may be bad.
* The MAF sensor may be faulty.

Possible Solutions

Use an OBD II Reader (or go tou your local parts store and they will for free) and reset the code and see if it comes back.
Then start with the cheapest, easiest repair procedures:

* Check the Mass Air Flow Sensor wiring/harness is connected properly and that there are no broken / frayed wires.
* Unplug and reconnect the MAF wiring harness a few times to clear the contacts.
* Check the voltage of the MAF sensor (refer to a repair manual for vehicle specific information).
* Replace the MAF sensor.

Thanks for using FixYa - a 4 THUMBS rating is appreciated for answering your FREE question.
%%%%

Dec 01, 2009 | 2004 Dodge Sprinter

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