Barometric Pressure Sensor

[92redman]

I've seen a few inquiries about the baro code in the 1g(code 25), but haven't found any diagnosis yet.

Here is my problem: Car had hard startup and a CEL came on going down the road. I suspected the ECU and so I took it out and put new caps in but that didn't help. I finally got a DRB scan tool on and found out it was the baro sensor and it was giving me a reading of 37.3 inMg which I think is the default.

I checked the power and sensor ground on the connector to the MAS and got 12.4V and I got a 4.9V on the other two. Should I have gotten that reading for the baro signal wire? because I was told that it probably wasn't biased and so I would have to do a continuity test from the connector to the ECU pin.

Prolly should add that I tried plugging in a different MAS but that may not be good either.

Any insight?

 

[92redman]

Anyone know if backprobing the BPS would give you an accurate voltage, or do I have to check it at the ECU?

 

[ritfordprobe]

This is the same problem I am having. If its not MAF or ECU, what can it be :-(

--mark

 

[92redman]

This is the same problem I am having. If its not MAF or ECU, what can it be :-(

--mark

It did turn out to be the ECU. I had replaced the caps but missed something when cleaning up the board. I went over the whole board again and didn't have the problem anymore.

 

[Jesse]

It did turn out to be the ECU. I had replaced the caps but missed something when cleaning up the board. I went over the whole board again and didn't have the problem anymore.

I just replaced the capacitors in my ecu and now I have the same problem with the barometric pressure sensor. Can you explain what you found on your ecu that was causing the problem?
thanks,
Jesse

 

[92redman]

You have to go over the area where the caps are with a magnifying glass. Look for corrosion, damaged traces, and specs of solder. Also make sure the caps have good contact with the lands and the lands are not damaged.

You may also have a damaged component on your board, there is a tech article here about what parts to replace from a spare ECU.