Question about 2002 GMC Envoy

1 Answer

I have a p0105 error. They say this is a dirty body throttle. How can I clean this myself? My car is a 2002 Chevy Envoy.

Posted by Anonymous on


1 Answer

  • Level 3:

    An expert who has achieved level 3 by getting 1000 points


    An expert that got 20 achievements.


    An expert that got 10 achievements.


    An expert that got 5 achievements.

  • GMC Master
  • 17,970 Answers

DTC P0105 - Crankshaft Position Sensor B Circuit Malfunction or Manifold Absolute Pressure/Barometric Pressure Circuit Malfunction

What does that mean?
The MAP (Manifold Absolute Pressure) sensor is part of the fuel management system. It reacts to changes in engine manifold pressure. The PCM (Powertrain Control Module) monitors the MAP sensor continually to properly run the engine. Changes in engine load require changes in the amount of fuel injected, and timing of the ignition system, etc. An engine under load has more manifold pressure(or less vacuum) than an engine that is coasting. As the load changes, the MAP sensor voltage signal to the PCM changes accordingly. To check the MAP sensor operation, though, the PCM watches other sensors to verify that the MAP sensor is working properly.

For example, the PCM compares the TPS (Throttle Position Sensor) signal to the MAP signal to verify the MAP signal isn't "sticking". If the PCM doesn't see a MAP sensor change immediately follow a change in the throttle pedal sensor, it knows there is a problem with the MAP sensor and sets P0105. Or, if the PCM notices that the TPS indicates the engine is under load, but the MAP signal indicates that the engine is "coasting" it, again, knows there is a problem with the MAP sensor or TPS and sets P0105.

Symptoms: Symptoms of a P0105 check engine light code may include:
* Poor running engine
* Engine runs rich
* Engine won't idle
* Engine backfires through tailpipe
* Engine misfire under load or at idle
* MIL (Malfunction Indicator Lamp) illumination
* In some extreme cases there may be no symptoms other than MIL illumination

Causes: A P0105 DTC could be caused by:
* MAP sensor vacuum hose disconnected or plugged
* Bad MAP sensor
* Bad TPS
* Damaged or problematic MAP sensor connector
* Damaged or problematic TPS connector
* Damaged wiring
* Short to reference voltage on signal circuit of MAP sensor
* Loss of ground to MAP sensor or TPS
* Open on signal circuit of MAP sensor
* Bad PCM

Possible Solutions: Using a scanner or code reader, turn the ignition on and engine OFF; what does the MAP sensor voltage read? It should be about 4 Volts for sea level. If you are at a higher altitude, it should decrease about half a volt or so for each 1,000 ft. of altitude (this will vary from model to model) Or if you have a separate MAF (Mass air flow) sensor on your vehicle, they are usually equipped with a Barometric pressure reading. If so, the Baro reading should match the MAP reading (they both measure ambient air pressure). If they're roughly equal, then, check for Freeze Frame data of the MAP sensor (if available).

NOTE: Freeze Frame data is the PCM recording a fault when it happens. It captures the readings of the various PIDS (parameter identifiers)available to troubleshoot what happened. It's like a recording of the problem as it happened. At idle a typical MAP sensor Voltage reading should be about a volt, and at WOT (wide open throttle) it should approach 4.5 to 5 Volts. As for the TPS, at idle, the voltage reading is about 1 Volt or less. As the throttle is opened the reading will increase to 4.5 Volts at WOT. Do the two readings make sense? For example, if the TPS reading on Freeze Frame data shows 2.5 Volts (indicating partial throttle) does the MAP sensor indicate a reading that isn't at either extreme? Using the Freeze Frame data (if available) compare the MAP reading to the TPS when the problem occurred. This can help you identify what happened

If you have no access to Freeze Frame data then check if the MAP sensor voltage changes when you apply vacuum to it. You can do this by mouth or a vacuum pump. The voltage should increase as you apply vacuum. If the reading doesn't change as you apply vacuum, make sure there are no obstructions in the hose to the sensor. If the hose is clear, the MAP sensor is usually bad, but it doesn't rule out the following from causing the problem: Does the MAP sensor appear to be stuck at less than .5 Volts? Then:

NOTE: This code shouldn't set if the MAP is stuck at extremely low voltage, however, I'm adding it in because there's no way to know for certain for which vehicles a low voltage condition may set a P0105.

1. Inspect the wiring harness and MAP sensor connector. Repair any damage
2. Unplug the MAP sensor connector. Also, at the PCM connector, remove the MAP sensor signal wire and check for continuity to the MAP sensor connector. If there is infinite resistance, then repair open in MAP signal circuit. If the signal wire has continuity to the MAP sensor connector, then check for 5 volt reference voltage to the connector and a good ground. If both are present, then re-install all removed wiring and replace the MAP sensor.

Does the MAP sensor appear to be stuck at full 4.5 voltage? Then:

1. Inspect the wiring harness for damage. Repair as needed
2. Remove the MAP sensor signal wire from the PCM connector. With a voltmeter measure the voltage with KEY ON ENGINE OFF. Is there 4.5 Volts? If so, unplug the MAP sensor and recheck. If it is still present, then repair short between the signal wire and 5 volt reference wire.
3. If unplugging the MAP sensor causes the voltage to disappear, check that the ground is intact. If it is, then replace the MAP sensor due to internal short.

MAP sensor codes include P0105, P0106, P0107, P0108 and P0109 .

Hope helps (remember rated this).

Posted on Jul 13, 2010

  • 2 more comments 
  • ozzyator Nov 14, 2010

    Hello, nice explanation thank you. I have one question...i have P0105 and i think, that it is NOT due to the MAP sensor failure. In my chartered fiat service they replace it, but the error came again. So i wanted to return the old sensor back (and refund the cash), but they told me, that "The old sensor is really bad, it measures the pressure well, but it does not measures well the temperature." Please tell me, my MAP sensor (T-PRT05 Fiat Stilo 1.6 16v) really measures both the pressure and the temperature inside the engine? I suspect them from lying... Thank You.

  • ZJ Limited
    ZJ Limited Nov 15, 2010

    When the MAF sensor failure, as they say, begins to get black smoke from the exhaust, check engine lights, the engine becomes unstable and handle it after a while so spoil the spark plugs (turn black), then you can put new spark plugs and the car is going to compose only for a few days until they gradually begin to smoke until you no longer run the car.

    IAC valve when the engine fails you off in low, usually when braking in a high or top. Turns easily but the next braking stops again, sometimes I vary the speed at minimum.

    The TPS sensor, the engine sometimes runs fast for a while and sometimes goes below normal.

    Check this last sensor that I mentioned, its possible that you have other fault code stored there.

  • ZJ Limited
    ZJ Limited Nov 15, 2010

    Its possible that this information helpfull: p0105_error_say_dirty

  • ZJ Limited
    ZJ Limited Nov 15, 2010

    Sorry, I mistake the link; this its the right link: (pdf)



1 Suggested Answer

  • 2 Answers

SOURCE: I have freestanding Series 8 dishwasher. Lately during the filling cycle water hammer is occurring. How can this be resolved

Hi there,
Save hours of searching online or wasting money on unnecessary repairs by talking to a 6YA Expert who can help you resolve this issue over the phone in a minute or two.

Best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.

Here's a link to this great service

Good luck!

Posted on Jan 02, 2017


Add Your Answer

Uploading: 0%


Complete. Click "Add" to insert your video. Add



Related Questions:

1 Answer

2002 envoy engine stumbling

Try cleaning the throttle body first. Make sure to clean both the front side and rear side thoroughly. Also, disconnect the battery while doing the cleaning, this will reset the computer and allow it to relearn to the cleaned throttle body.
Unless you have the check engine light on and can retrieve a fault code, do not start to change parts. With the mileage you have, you may want to change the O2 sensors.

Nov 13, 2011 | 2002 GMC Envoy

1 Answer

I replaced my battery in my 2004 GMC Envoy last week now the car cuts off/stalls whenever I come to a complete stop. It fires right back up once I put it back in park and start it again.

The throttle body needs to be cleaned, When you disconnected the battery, the computer reset to factory defaults and now with a dirty throttle body, it will run poorly at idle. Make sure both the front side and rear side of the throttle body are cleaned thoroughly.

Sep 08, 2011 | 2004 GMC Envoy

1 Answer

2003 envoy changed battery out and now when i put on ac truck stalls and dies

The throttle body needs to be cleaned, grime in this area prevents the throttle plate from closing completely and allowing air to enter, making the air/fuel mixture lean. Make sure to clean the front and back sides of the throttle body. Also, disconnect the battery during the cleaning process to allow the computer to reset and relearn to the cleaned throttle body.
When you changed the battery, the computer was reset back to factory settings and with a dirty throttle, the fuel/air mixture is incorrect.

Aug 10, 2011 | 2003 GMC Envoy

1 Answer

Reduce engine light came on in my 2002 envoy and it feel as if the truck is not getting any power, why is that? the truck slowed down so i pulled over cut it off an started it back up. after starting back...

Reduced engine power is just like a safe mode. First things first, clean your throttle body. It's possible the butterfly is sticking. Disconnect the battery, clean your throttle body with throttle body cleaner, must be nice and shiny. When finished, drive around for 20 minutes or so with all accessories off. This will allow the computer to relearn a properly functioning throttle body.

Mar 25, 2011 | 2002 GMC Envoy

1 Answer

Recently i replaced battery in my 2002 envoy, now if a/c is on it idles rough and will stall, can you help me with solving this problem

Clean your throttle body. Disconnect the battery, and take the plastic resonator and large hoses off that attach to the throttle body. Clean with throttle body cleaner, must be nice and shiny. When finished, drive around for 20 min or so, so the computer can re-learn the properly functioning throttle body. Your computer learned some bad habits with the dirty throttle body, so when you disconnect the battery and reconnect it, it thinks the throttle body is clean and functioning properly which is not the case. If you do it yourself, can cost you a can of throttle body cleaner $7.

Feb 19, 2011 | 2002 GMC Envoy

1 Answer

Hello my name is fernando i have a 2002 gmc envoy im having a problem with my car took it to shop and they cant find the problem wen i turn on heater or ac the car idles up and down then turns off as long...

Easy one. Probably does this with either your A/C on, and OR your de-froster. The de-froster uses the A/C to dry the air. You must of either put a new battery in recently or disconnected it. Clean your throttle body with throttle body cleaner while the battery is disconnected. When finished drive around for 20 minutes or so with all accessories off. At this point your computer will re-learn a properly functioning throttle body. Your computer learned some bad habits with that dirty throttle body, so when the battery was disconnected for one reason or another, it thinks the throttle body should be functioning properly, which it is not. I'd find a new mechanic, this is a very very common problem with Envoys and Trailblazers. If you decide to do it yourself, it will cost you just a bottle of throttle body cleaner, about $7.

Feb 15, 2011 | 2002 GMC Envoy

1 Answer

I just change my car battery in my gmc 203xl envoy but its running with less power and shake when i slow down what is wrong please can u tell me thanks

Clean your throttle body with throttle body cleaner, must be nice and shiny. Do this with the battery disconnected. When finished, hook the battery back up and drive around for 20 minutes or so, so the computer can relearn the newly cleaned TB. Your computer learned some bad habits with the dirty throttle body, so when you disconnected the battery, it thought the throttle body was clean, therefore, you'll get performance problems. Especially when the defrost or A/C is on.

Jan 16, 2011 | 2003 GMC Envoy Xl

1 Answer

My 2002 gmc envoy stalls when i turn on the ac

The throttle body needs cleaning, the butterfly and surrounding area has built up deposits that prevent the butterfly from closing all the way. Visit and search for throttle body cleaning.

Aug 09, 2010 | 2002 GMC Envoy

1 Answer

2006 Envoy stalling when idels and won't stay running

Clean your Throttle body and pay attention to the Idle Air Control (IAC) valve passageway to try to clean the IAC. A dirty or faulty IAC will cause your engine to stall at idle, the job of the IAC is to open the passage way through the throttle body to regulate the amount of air to enter the engine to keep it from stalling when the Envoy is at idle.

Start with the simple and clean the throttle body and inspect any loose or damaged wire leads to the throttle body. Replace or repair any signs of damage.

Thank you for using Fixya and good luck.

Apr 10, 2010 | 2006 GMC Envoy Xl

Not finding what you are looking for?
2002 GMC Envoy Logo

2,313 people viewed this question

Ask a Question

Usually answered in minutes!

Top GMC Experts


Level 3 Expert

80339 Answers

Colin Stickland
Colin Stickland

Level 3 Expert

22326 Answers

Ronny Bennett Sr.
Ronny Bennett Sr.

Level 3 Expert

6927 Answers

Are you a GMC Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides