[LasCruces-V]

I tried searching before posting sorry if this is a repost. I have a 05 CTS-V LS6 of course mods:

Patriot performance stage II.5 heads
cam- 232/234 .595/.596 lift
headers
corsa exhaust
cold air intake
port and polished TB (which TB might be the cause)
50 wet shot

those are the main mods.

I had a friend HP tune my car. but before we tuned it we took it on a test run after the mods and under full throttle went into power reduced mode. everytime. after the tune it was fine. well its doing it again. we did have an issue on not being able to do a speed density tune where we tune out the MAF. the car would not allow it. when we would try it would go into power reduced mode right away. so we tuned it the best we could w the MAF still in play. now it runs fine under full throttle unless i run it from a dig and shift hard into 2nd. as soon as it hits 2nd it goes into that mode again. but 2nd to third full throttle pulls and so forth its fine. i can however go from a dig and if i shift slow and ease into full throttle into 2nd its fine. I think since we had to tune w the MAF still on the computer is retuning itself. keep in mind right after the tune i could run the car to hell and back and it would run strong. nitrous was tuned w a wideband and thats irrelevent to this problems. i have only used it when we tuned for the right pins... thank you guys for your help!

 

[Twitch]

No time to look for it now, but check HPtuners forum. Just search "reduced power". I think it's code 1506, not sure though. You may need to increase the parameters. Shouldn't be too hard to find.

Side note: If it only happens on 1-2 hard shifts, it may be doing your diff a favor. I always ease into 2nd and 3rd gears.

Tony

 

[LasCruces-V]

No time to look for it now, but check HPtuners forum. Just search "reduced power". I think it's code 1506, not sure though. You may need to increase the parameters. Shouldn't be too hard to find.

Side note: If it only happens on 1-2 hard shifts, it may be doing your diff a favor. I always ease into 2nd and 3rd gears.

Tony

that is true never really thought of it that way... just irritating... then of course it pulls timing when it goes into that mode.... so parameters might be the problem... ok i will try that. thanks a lot. any other info will be greatly appreciated. also is it even possible to speed density tune on these computers? my tuner tunes SD and he ran into the issue of not being able to on my car and another GTO which was an LS1 but it was a 05. so he was thinking maybe the computers are different since they are newer?? sound right?

 

[justin311]

My car went into reduced power mode......caused a bunch of codes to pop up. It was a bad battery issue.

 

[LasCruces-V]

My car went into reduced power mode......caused a bunch of codes to pop up. It was a bad battery issue.

i will check the battery. thanks. car runs great until its FT hard shifting but only from 1st to 2nd.

 

[Max-Q]

My car went into reduced power mode......caused a bunch of codes to pop up. It was a bad battery issue.

Do you remember what codes it threw? Mine is at the dealer now for the reduced power mode problem and they can't seem to find the problem. The throttle body, accelerator pedal and TPS have been replaced and it still happens. Now I'm wondering about the battery.

 

[Max-Q]

Update on my reduced power problem- ends up it was the pigtail connector to the TPS. The dealer replaced the connector and problem solved.

You might want to check the connector.

 

[ctsv154]

I had this problem as well. The bottom pin in mine corroded and would cause it to go to reduced engine power.

 

[Max-Q]

I had this problem as well. The bottom pin in mine corroded and would cause it to go to reduced engine power.

Must be a common problem. Apparently mine had corrosion on the pins too. I wonder if some sort of electrical grease would prevent it from happening in the future.

 

[LasCruces-V]

checked my pigtail looks fine. the code it throws is p0068. its been running really rich now. it killed my bank 1 sen 1 o2. im wondering if thats whats causing the problems maybe it was going out causing the car to run rich? have to order it so will be 2-3 days. that code however has to do w the engine load under full throttle. that could be caused by wrong parameters set in the maf right? havent been able to get with my tuner tho. so the cars been parked. is there any special way to tune these cars? i have read that GM screwed up on the computers w the 04-05 models causing the tuners not being able to communicate w the computer right. when my tuner tries to get the computer to ignore the codes so he can tune it says it cant communicate w the cabin computer. any other advise would be greatly appreciated. thanks guys for all the responses!

 

[Twitch]

Have you checked for vacuum leaks on the intake side? That would cause you to run lean, and maybe set the code since the engine is getting more air than the MAF is reading.
I have no problems using HPTuners with my 05 PCM. But you neen to make sure that everything is off in the car. Radio, lights doors closed. Being Cadillacs, our cars have more gadgets than say an F-body. Sometimes they interfere with comunication between the PCM and tuner. I used to have this problem, but now that I turn everything off, it always works perfectly.

Tony

PS Make sure to post up what the problem was

 

[LasCruces-V]

Im going to take today and tomorrow off and start to take the motor apart again. im hoping to find something lose or missing. i read that even headers being lose will cause the computer to wack out? im getting the o2 this afternoon gonna pop that guy on and have my tuner reflash with the same tune and see how that goes. i will be sure to post what the problem is. this is so frustrating!! lol where is a common vacuum leak on the intake side just out of curiousity? thanks twitch

 

[repenttokyo]

does reduced mode always throw codes, or is there another way to recognize it?

 

[ctsv154]

Well to get reduced engine power the computer has to throw a CEL first. If you go to reduces engine power you will get a message on the NAV screen stating such and the car shakes ans sounds like it's got a cam only it has no power ans dan only rev to like 3k or something.

 

[LasCruces-V]

ok update................ My fix was new O2 sensor! no more power reduce mode.... weird thing was it wasnt throwing a code the first months of running messed up. it finally threw it and i changed it and problem solved! BUT my car did need a reflash w the same exact tune we had done before. i was kinda looking at the o2 sensor as a fix before as i stated before because the car started to smell really rich at stop lights and backfire alot some days and not others. so I figured it had to do with the fuel/air ratios. and thats where the o2 comes to play! i hope this will help someone else in the future! Thanks guys for all your inputs! Car is running strong now! cant wait to take it to TSP and get a full dyno tune and see what kinda power im pushing......

 

[vavavavance]

Hello,
Not to hijack thread but I have a question?
Driving to work the other morning, reduced engine power engine light,tc light come on.
Limp it back home.Park it...Back home 12 hrs later...Pulled ecm fuse and let sit for few minutes..reinsert fuse and start up.
Full power ..no lights on dash..took for drive for about 10 mins..seems fine now.
Taking it in this week to get scanned ..If its the tps..can i do this myself..throttle relearn and other steps involved?
Do i need a new throttle body assembly or not?
No mods
Thanks in advance guys

 

[kbraniff]

Actually... It seems the "reduced power" warning could relate to just about anything. When it happened to me I drove the car around the block and shut the engine down when I got home. Just a few minutes later I started the engine. There was no active warning and the car ran perfectly. When I had the codes checked I got C0241, C0242, U1016 and U1301. The actual diagnosis was corroded wiring to the electronic brake control module. My suggestion... Wait on doing any repairs yourself until you have the codes checked.

 

[Devildude24]

When I had this issue with mine, the TB harness was not in good shape. Namely, the insulation on the wires wore away and they would touch when I gave it too much gas on a shift. After some cutting, soldering, and heat shrinking, it's been fine. I'm sure you've done this, but check the wires under the tape right at the connector and back about 6 inches. That's where my issue was.

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