Air Pressure Sensor Location

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Slardy

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I have the manual, I have spent quite a while searching this forum, but I still can not find the air pressure sensor that is under the seat. I have checked out my Intake air pressure sensor and it is OK. I have been getting codes 13 and 14 and yellow engine light when starting cold in the mornings (~50 degrees F). But after the engine is warmed, if I restart the engine, the yellow light goes off and all is normal.

Does anyone have a photo or a detailed location description? Please.

Slardy

 
Extreme right of the picture, midway from top to bottom.

(Click on image for larger view)



Picture from my (ex) 2006.

[edit] Shown in your workshop manual around page 2-59, item 30 (if it's the same as mine).[/edit]

 
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There is only one intake air pressure sensor and one intake air temperature sensor.

The air pressure sensor is under the tank, as shown in trophy's photo. It has a vacuum line run to it.

The temp sensor is screwed into the back side of the air box at the rear of the tank (under the seat).

 
The air temperature sensor in my workshop manual is shown on page 2-81 and is item 6. Judging by the drawing, it is below the tool tray. Sorry, no pic.

However the error codes 13 and 14 refer to the pressure sensor. I'd suggest checking its connections for corrosion.

 
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Yes, the errors are specific to the pressure sensor. But he was looking for a sensor under the seat.

That's the only one that I am aware of under the seat area.

 
Folks,

I forgot to mention that my FJR is a 2007 with ABS. The manual that I have is for an earlier year and does not depict the location of the Atmospheric Pressure Sensor properly. I cannot locate it. I looked under the tool tray (difficult to remove)and then behind the ECU (after removing it). What a PIA.

Anyone with a 2007 FJR that has located the APS under the general environs of the seat, or has a 2007 manual, can you help me?

Slardy

 
The intake air pressure sensor is on the fuel rail, left side in the vicinity of the PAIR solenoid. Some would refer to this as the MAP sensor. This is the one you want.

What you are looking for under the seat is the intake air temperature sensor...... it's in the air box. If you remove the air cleaner cover, at the top right corner, you will find a wire that looks pinched coming out of the air box.

Error 13 - Open or shorted circuit, Error 14 - Vacuum hose malfunction (clogged or detached).

To test the sensor per FSM, Intake Air Pressure Sensor output voltage should be 3.75-4.25 V. Probe pink/white and black/blue wires.

Let's hope you find a clogged hose...........

 
The air pressure sensor is shown in my picture in my first reply, this is of my 2006, identical to your 2007.

[edit]

Your Gen 1 manual isn't being helpful. The 2006 manual shows this:

AitPresSens_06.jpg


The item marked 30 is the air pressure sensor.

[/edit]

 
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OK Folks,

Thanks for your help. I appreciate you spending your time to help me with my problem.

The mystery is solved. My 2004 FJR had 2 air pressure sensors. One was the Intake Air Pressure Sensor. The second was the Atmospheric Pressure Sensor. This one was located under the seat in the vicinity of the ECU. Nowadays, the FJR Atmospheric Pressure sensor is inside the ECU.

My 2007 has only one air pressure sensor! My reason for looking for the second sensor was that I planned to swap them to see if my intermittent problem went away. I do get a satisfactory voltage reading with the key on. My next step is to go to Diag 3 and see if the sensor responds to a brief push of the started button.

Slardy

 
Several people have discovered that the hose going to the sensor has been plugged with some kind of spooge. It appears that there may be some back-streaming from the intake into the hose.

 
Several people have discovered that the hose going to the sensor has been plugged with some kind of spooge. It appears that there may be some back-streaming from the intake into the hose.
...and then what are the symptoms of this plugging?
uhoh.gif


 
Several people have discovered that the hose going to the sensor has been plugged with some kind of spooge. It appears that there may be some back-streaming from the intake into the hose.
...and then what are the symptoms of this plugging?
uhoh.gif
Same as a 'defective' sensor because the air passage is blocked. When you have the Intake Air Pressure sensor diAG code 03 active and you push the starter button either the reading on the diAG screen won't change as much as it should or won't change at all. The service manual doesn't specify how much the sensor should change, just that it will change when the starter button is pressed. Don't blow or squirt anything in the hole of the sensor to clean it, this would kill the device.

The Atmospheric Pressure Sensor is mounted under the seat locking brace that runs from side to side of the frame, it's a pain to get to. IIRC, it's on the right side of the brace, you should be able to see it even though it's hard to get a wrench on it. I have swapped the one under the seat with the one on the left end of the fuel rail before like you want to try. I have also found that my FJR ran just fine with the Intake Pressure sensor unplugged, the ECU simply uses a look-up table in place of the sensor.

 
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An '07 doesn't have an atmospheric pressure sensor. The intake pressure sensor (MAP) provides both intake pressure and atmospheric pressure.

There was a recall dealing with how this sensor via ECM software provides an approximation of atmospheric pressure (AP). When the throttle is almost closed the ECM uses the MAP sensor pressure reading and approximates AP.

And, of course, at "key on" before the engine is cranked the MAP pressure is the AP. The ECM has to approximate the AP whenever the engine is running.

 
^^^^^ I looked at Lele's post and saw a Gen I and now going back to the OP I see he has a Gen II. Yes, the Gen II does not have an atmospheric pressure sensor. It is the Gen II which has a higher propensity to having a plugged hose going to the Intake Pressure Sensor.

 
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From the parts diagram it appears that the '13+ FJRs have a separate atmospheric pressure sensor.

On the "Intake 2" diagram two identical pressure sensors are shown. One connects to the intake pressure hose network. The other sensor appears to be bare with no hose connections. A reprise of the Gen I configuration!

 
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