Dtc 0107

MadMaxx61

Devilmaxx
Oct 13, 2008
5,458
1
36
39
Windsor, Ont, Canada
Not just to diesel but some info

P0107 - Manifold Absolute Pressure/Barometric Pressure Circuit Low Input

OBD-II Trouble Code Technical Description

Manifold Absolute Pressure/Barometric Pressure Circuit Low Input
What does that mean?

The Manifold Absolute Pressure (MAP) sensor responds to changes in the intake manifold pressure (vacuum). 5 Volts is supplied to the sensor from the PCM (powertrain control module). Inside the MAP sensor is a resistor
that moves in relation to manifold pressure. The resistor varies the voltage between about 1 volt to 4.5 volts (depending on engine load) and that voltage signal is returned to the PCM to indicate manifold pressure (vacuum). This signal is essential for the PCM to determine fuel delivery. P0107 sets when the PCM sees that the MAP signal voltage is less than .25 volts which is too low.

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Potential Symptoms

Anytime the MAP sensor signal is low the vehicle will likely have a very difficult time starting. Other symptoms may include:

* Hard to start
* Long cranking times
* Sputtering/missing
* Blowing black smoke
* Poor fuel economy
* Dies intermittently
* MIL(Malfunction Indicator Lamp) illumination

Causes

The causes of a low MAP sensor signal circuit (P0107) could be any of the following:

* Bad MAP sensor
* Open or short in the signal circuit
* Open or short in the 5 Volt reference circuit
* Ground circuit open or shorted
* Bad PCM

Possible Solutions

First, using a scan tool with the Key on and engine running, monitor the MAP sensor voltage. If it is reading less than .5 volts, turn engine off, unplug the MAP sensor and, using a DVOM (digital Volt/Ohm Meter) check for 5Volts on the 5 Volt reference circuit.

1. If there is not 5 Volts on the reference circuit, then check for the reference voltage at the PCM connector. If it is present at the PCM connector but not the MAP connector, repair the open in the reference circuit between the PCM and MAP harness connector. If 5 Volt reference is NOT present at the PCM connector, check powers and grounds of PCM and repair/replace as needed. (NOTE: On Chrysler products, a shorted Crank sensor, Vehicle speed sensor or any other sensor that utilizes the 5 Volt reference from the PCM can short out the 5 Volt reference. To fix simply unplug each sensor one at a time until the 5 Volt reference reappears. The last sensor unplugged is the shorted sensor.)

2. If you have a 5 Volt reference at the MAP connector, jumper the 5 volt reference circuit to the signal circuit. Now check the MAP voltage on the scan tool. It should be 4.5 to 5 Volts. If it is, replace MAP sensor. If not, repair open/short in the signal circuit wiring and re-check.

3. If all appears okay, perform a wiggle test. Start engine and manipulate the harness, connector and tap on the MAP sensor. Note any changes in voltage or engine speed. Repair connector, harness, or sensor as needed.

4. If the wiggle test checks out, use a vacuum pump (or just use your lungs) to draw a vacuum on the MAP sensor vacuum port. As you add vacuum the voltage should decrease. With no vacuum, the MAP sensor should read approximately 4.5 volts. If there is no change in MAP sensor reading on the scan tool, replace MAP sensor.
 
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The Neens

BFD
Staff member
Aug 10, 2006
4,596
1
36
Monrovia, Ca.
This happened recently to a friend's '08 C4500...Dealer said it was a connection problem at the MAP sensor...They did a quickie repair until the new harness comes in...No codes or limp mode since...
 

The Neens

BFD
Staff member
Aug 10, 2006
4,596
1
36
Monrovia, Ca.
how would i go about fixing my 0299 problems? its really getting annoying, the truck has a loss of power at high rpms

I would put one of your engine/performance mods back to stock until you eliminate the problem...Once you find out what is causing it, you can make a decision...
 

JD4440

<< Lo-Carb Monster
Feb 27, 2009
1,776
1
0
Orlinda, TN
Damn, I knew that at one time :spit: I'll get the code about every time I start it . Sometimes I'll clear it and it comes back before the screen changes on the CTS ! If I clear it after I get going and maintain boost it'll stay gone most times. Twice it has set while driving and caused a harsh downshift, and then yesterday it did it and bogged the truck down :mad:
What'd it end up being on yours Ben ? Mine may be a connection issue I hope from the sensor being backwards on my EGR delete.
 

x MadMAX DIESEL

<<<< No Horsepower
Dec 30, 2008
7,535
1
38
34
Lexington, Ky
I really don't remember, but I havent had them for along time. That was when I had a mp8, quadzilla, and a boost controlller on the truck iirc. I'd have to look at my tune tomorrow to see if those codes are blocked, but I doubt it. Good thing to start with is to clean the connection really good and use some dielectric grease... What code(s) are you having? Also IIRC 299 is an underboost code, maybe you have a leak somewhere?
 

JD4440

<< Lo-Carb Monster
Feb 27, 2009
1,776
1
0
Orlinda, TN
Just the p0107, every now and again I would get a 299 but only at odd times cruising the interstate.
When I log barometric pressure I get .6v with an average of 1.4v. when I bring the RPM up it acts like it hits a rev limiter very slowly at 2300rpm and when it does it puffs a cloud of pale smoke.
 
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x MadMAX DIESEL

<<<< No Horsepower
Dec 30, 2008
7,535
1
38
34
Lexington, Ky
Buddy I don't know. I just checked my tune and that code isn't blocked from popping or anything. I kinda fixed itself I think. Sorry I can't be more help but it was so long ago I don't recall.
 

JD4440

<< Lo-Carb Monster
Feb 27, 2009
1,776
1
0
Orlinda, TN
OK, just checked the voltage at the sensor. I'm getting .001-.002v on the 2 pins @ the plug and 5.02 on the pin to itself. So this means the sensor is bad ?