350 HRSS

Last night, I went down to upload the current LT1 Edit program that is on my car w/ my laptop. Something really weird happened. I was attempting to use PCMread, so nothing crazy could happen (blown PCM, etc.). I plugged it in, and started the connection. I heard the fans click on, and everything like normal. Then, it just lost the connection. And I was like????



So, I unplugged it and tried to start it. All it did was click a little. I have blown a PCM before, so I was a little worried. I checked the battery voltage. It was 10.25 on my voltmeter. And I know to use Edit, you have to have at least 11.6 volts. THAT is just a 7 month old Optima, and it also has a new Powermaster alt. So, we jumped the car off and it cranked right up. THEN, it starts stuttering and it shut off. I ran through the scanmaster, and it was a code 33. MAP sensor. I have had this code before, but it has never STUCK.



I pulled the PCM fuse, and that did not clear it. I then unhooked the neg. batt. cable, and that cleared it. I had an old MAP sensor and I switched it out, and the code did not come back when it was idling. I put the other one on, and the code came back. HOW could the MAP have went bad just like that? I just came back from Richmond as you know, and had no issues. I noticed the MAP sensor also has a small springy seal around it, and I kinda rolled it around a little to get the ribs back out.



Have yall ever seen anything like this before? Or why it happens? I am really stumped here. If yall can help me out w/ this or offer some advice, it would be great. I just ordered a new one from the dealership for around $30. The replacement I had on there, that gave me the code, was a Napa (Echlin) part.

Thanks for any help.

Injuneer

It doesn't sound like it "went bad just like that".... you have been having intermittent problems with DTC 33 for a while according to your post.

Did you check the harness connector? They dry out and crumble and the contacts are intermittent.

The code sets when intake manifold pressure is more than 68kPa at idle. Do you have some sort of a large cam? If the seal on the MAP sensor was faulty, that would show up as a vacuum leak, making the MAP higher at idle. Might all be connected.

350 HRSS

I have a CC 306. I just can't understand how I switch one out, and the code goes away. I didn't get the code w/ the old stock one, but did w/ the newer one (less than a year). Either way, I am trying that new sensor.

I did check the connections. I unhooked the MAP sensor, nothing wrong there. Everything looked clean. The car wouldn't stay cranked w/ that code.

Thanks for your reply...