Baro Sensor error code

[SeanC]

Hey guys,

On my way home today my dreaded SES light came on. When I got home I hooked up my scanner and I'm getting:

P0107
Manifold Absolute Pressure/BARO sensor low input

To be honest with you, I have never even heard of this sensor. Where is it located? Do you think it just needs to be replaced?

Thank you!

[Rob B (shoebox)]

That would be the MAP sensor. Check the connector first.

[Injuneer]

Its one of the most critical sensors in the engine. It represents "engine load", and is used as one axis of the spark timing tables (RPM is the other axis), and along with RPM to define the long term fuel correction (BLM) storage cell boundaries. If you scan the engine, you can calculate engine vacuum by subtracting MAP from the barometer reading. The 93's use it to calculate the "density" portion of the speed-density air/fuel control system, and even the 94+ "mass air" cars use it when speed-density fueling is required to back up a faulty MAF sensor.

As Rob mentioned, check the green harness connector first. They dry out and start to crumble providing poor contact and erratic sensor readings. Jiggle the wires while reding the voltage between the signal wire and the ground wire. MAP at idle will typically not go below 30 kPa (9.5 "Hg).

[SeanC]

It looks like the connector is a bit corroded...Does GM just sell the green connector and then you can just solder it in?

I'm suppose to be going to a car show tomorrow with my car. Should I not drive the car at all with this sensor not working right? It looks like at idle I'm getting anywhere from 9.0 to 9.5 Hg.

[Jeff_in_Atl]

Most connectors you can get as a pigtail from GM ie a connector with 12" of wire and a crimp connector. Shoebox has a list of pigtails on his site. I haven't looked to see if that one is there or not.

What I would do first is try cleaning the connector before you start cutting the factory harness. You can do it with baking soda and water or you can buy a can of battery terminal cleaner and spray it in the connector. Then put some dielectric grease on it and plug it back in.

[Jeff_in_Atl]

Of coarse he does.
http://shbox.com/1/Parts.htm
AC-Delco p/n---Usage---------------------GM p/n
PT123----------1993-1997 MAP sensor-----12085502

[BrdWAtti2d]

Check out these guys, reasonable prices.
http://www.eficonnection.com/eficonn..._pigtails.aspx

[Injuneer]

It looks like the connector is a bit corroded...Does GM just sell the green connector and then you can just solder it in?

I'm suppose to be going to a car show tomorrow with my car. Should I not drive the car at all with this sensor not working right? It looks like at idle I'm getting anywhere from 9.0 to 9.5 Hg.

No problem with those numbers at idle. The code sets when MAP drops to about 10kPa or about 3"Hg. You've got in intermittent wiring problem.

[dochidalgo]

A word of caution here:

In my car, the green connector had broken the clip, so the connector came loose frequently. The GM dealer mechanic, took off each one of the 4 wires (with a tiny plane screwdriver)from the green connector and re installed in a brand new green connector.
He did not recommend me to cut & weld the wires because it may alter the electric signals via ohms? volts? Don't remember. Would be right this assumption?

regards
dochidalgo

[Injuneer]

A well-made splice, soldered and covered with heat-shrink insulation, will not cause problems.

[SeanC]

So I replaced the corroded wiring harness connector because I couldn't get it to work after cleaning it. Started it up and it was running fine, no SES light. I drove down to Maryland and back, the car ran great and I had no problems. I get into my home town coming back from my trip and my SES light comes on AGAIN!!! I hooked up my scanner and sure enough I was getting the same code. My scanner is reading a constant 3.2"Hg at all speeds (I know its suppose to be quite a bit higher). Do you think the sensor itself is bad? I really need to get my car running right because I really don't have a car right now...I am going to have to drive it a little but im trying to avoid driving it as much as possible. What do you guys think?

[SeanC]

I just erased the code....the live reading is now coming back normal. Its reading 9.4"Hg at idle. I have no idea why it wasn't reading right before. Could the sensor just be going bad?