My 08 SS/TC has been having some weird issues.

The first is that all of a sudden I would notice that it felt very sluggish (gun it and the car takes off slow). Then a CEL would show up shortly thereafter. When I got it checked it was a P0236, which GM flags this as a 'turbocharger boost sensor' issue. Then maybe a day later, the power would return and the light would go away. This has happened three times with about a week or two in between.

Now, this week, I was driving on the freeway when all of a sudden I felt an instant loss of power, and my car started bucking. The RPMs would drop and the engine would feel like it was choking causing the car to buck. I tried dropping the car in a lower gear and gunning it, but no matter what the boost would not go above 0. I was close to my destination and made it there ok, and then later in the day when I drove it again everything was fine.

Today, 2 days later, the same thing happened again, and the car was choking even worse, even in first gear from a stop. I pulled over, and looked under the hood for something obvious but found nothing. After 5 minutes, I started the car again, drove off and everything seemed fine.

Has anyone had similar issues or have any idea what the heck is going on. I don't get it. I would think that if something was broken on the car it would be performing bad all the time. I don't see how something goes wrong and then seemingly fixes itself for a while. Seems really strange.

 

Whats done to it mod wise?

 

Im no expert, but if the pcm's adaptive capabilities are making up for the boost sensor problem it could cause an intermittent problem like that I would think. I would start with the sensor myself.

 

try replacing the sensor, its probable that it has gone bad. your car is going into "limp mode" when the message center says "power-reduced" to prevent damage to engine , etc.

 

I had same code and lack of power was well, worked fine next day when I drove it to dealer, they replaced my tmap sensor under warranty. (course they ordered wrong one even though I told them I had gms1 and brought them the instruction sheet that comes with it)

 

I have the GMS1 mod and K&N drop in to answer FasterIsBetter's question.

Is the TMAP sensor the turbocharger boost sensor? I'm guessing it stands for turbocharger manifold absolute pressure?

 

On another note, I've never noticed that my car displays a 'power reduced' message.

Also, when I'm in low gears at low speeds if I let off the throttle all the way sometimes the car will jerk. Is this normal?

 

The T stands for Temperature because it has an iat sensor built in.

I would guess that the wiring to the sensor has a bad connection. If it was spliced, it probably has a loose crimp or some corrosion in the connection.

 

^^This. Go back to the dealer that did it and have them solder the wires cus they just crimp them. What is happening to you has happened to a lot of people

 

I had this same code and reduced power on my Cobalt, and it also had GMS1. I had a K&N drop in as well. I don't honestly know how it was fixed, but I took it to the dealer to check it out, including the stage 1 sensors but they couldn't find anything wrong...

Funny thing was, I cleaned my K&N filter and I never got the code after that...possibly coincidence, but a possible fix? Never hurts to try considering the cleaner kit is less than 20 bucks.

 

If I can be of assistance in working with a dealership, please let me know!
Sarah
GM Customer Service

 

I'd PM her....

 

yep i second this one.

 

GMS1 is notorious for this. You can probably find 100+ threads on this exact topic. It's always either the connections they made when they spliced in your 3bar TMAP sensor pigtail, or the A/C has dripped water all over the connections and corroded them. If you had the GMS1 installed at a dealer, take it back and have them re-do it.

 

I didn't have the GMS1 put on it. I bought the car 2 months ago and noticed the GMS1 sticker and sensors, so I don't know who installed it.

Is the TMAP sensor what the P0236 is flaggin as the 'turbocharger pressure sensor?' Does anyone have a picture or can tell me where it's located?

 

its just the map sensors... theres one on the intake manifold and one on the charge piping between the ic and throttle body. its probably the one on the charge piping as its a pita to get to

 

Yeah I think I might know what you're talking about. Is it like 16 inches or so below the upper MAP sensor, both of which are Bosch (GMS1)?

 

that sucks...

 

Yes, and towards the passenger side. It is on the charge tube, right by the AC compressor.