Reduced Engine power, Check Engine.. and other errors...

[bkboatnsleds]

So tonight - on my way home I get the DING DING - and see 'Reduced Engine Power' on the dash.

Then the ABS light came on..

So I pulled over - as you cant even go above 2k rpm's when this happens.

Re started the truck 2 - 3 times and it finally would rev up normally. I went back to my shop, and pulled the codes and got the code P1516

"Truck is drive by wire"

I cleared all the codes - and its been fine since.

Now this happened to me once before but it was when the truck was parked outside in -20 some off weather.. and I think the throttle body actually was froze.. I never had this issue since then.

So Not sure what the issue is but I take it as it has to be one of a few things - the pedal sensor or the servo on the Throttle Body going bad.. A glitch in the system? I don't know. Anyone else have this?

I also have NO idea about why the ABS came on - but I got the codes of : C0291 and CO237


And lastly - this is random - but when the truck went into reduced engine power / limp mode the doors unlocked.. is this a normal safety thing? Kinda weird!

 

[chip]

I just had the same shit happen to me, but I didn't get your codes (I got a TPS code). When the weather warmed up, I cleared the codes. That took care of it for me.

 

[03YukonNH]

I had this happen to me a few times back in June/July 2010 when I first bought the truck. It happened about 3-4 times all within a month and was start to p*$$ me off. I ordered a new APP sensor for the pedal and was going to replace it if it happened again and it hasn't done it for over a year. Weird.

 

[Freedom Motorsports]

Sounds to me like ya'll got some moisture in your wiring harness or plugs. I would inspect the plugs and harness for signs of moisture and whether you actually see the moisture or not, take a heat gun (hair dryer) and attempt to dry the plugs out and see if it happens again.

 

[bkboatnsleds]

Maybe I'll try that - and put a little dielectric grease in there too..

Thx.

 

[TnTahoe]

Mine did this about a month ago, I just pulled into a parking lot turned it for about a minute then it started up just fine and ran fine, no problems since. Had my codes read about two days ago and got my left front wheel speed sensor wasnt reading and something about fuel evaporator or something like that, think it had something to do with the gas cap. But I dont think either of those codes had anything to do with the "Reduced Engine Power"

 

[chip]

Sounds to me like ya'll got some moisture in your wiring harness or plugs. I would inspect the plugs and harness for signs of moisture and whether you actually see the moisture or not, take a heat gun (hair dryer) and attempt to dry the plugs out and see if it happens again.

You think so? I don't know. I'm hoping it's dirty, frozen throttle body issue. The next time I change the oil, I'll take a look at it. Damn, I hope you're wrong!

Maybe I'll try that - and put a little dielectric grease in there too..

Thx.

Not a bad idea. Post pics?

 

[Freedom Motorsports]

You think so? I don't know. I'm hoping it's dirty, frozen throttle body issue. The next time I change the oil, I'll take a look at it. Damn, I hope you're wrong!

Yeah, I had a similar issue on a couple of different trucks. The last time it was the Dmax throwing a throttle position sensor code with zero throttle response, so I changed it and still nothing. When I checked the harness good, water had gotten inside the wire loom and made it inside to the sensor plug, once I dried everything out it was fine. So now I have a perfectly good TPS here that I don't need.

I'm also thinking that if the throttle body was that bad you would have more consistant issues, ie: possible rough idle, etc. I could definitely be wrong though.

However, I have also seen an ignition going bad cause funky things like that to happen as well.

 

[chip]

Yeah, I had a similar issue on a couple of different trucks. The last time it was the Dmax throwing a throttle position sensor code with zero throttle response, so I changed it and still nothing. When I checked the harness good, water had gotten inside the wire loom and made it inside to the sensor plug, once I dried everything out it was fine. So now I have a perfectly good TPS here that I don't need.

I'm also thinking that if the throttle body was that bad you would have more consistant issues, ie: possible rough idle, etc. I could definitely be wrong though.

However, I have also seen an ignition going bad cause funky things like that to happen as well.

You make some scary points! You have pics of the plug you're talking about?

 

[Freedom Motorsports]

I don't have a pic, but it is on the side of the throttle pedal, when you order one you get the pedal and plug as an assembly.

 

[03tahoe2012]

Old thread I know but mine is throwing the same codes.....but I think the reason is because I am putting too much amperage on the battery...what do you guys think??? I really need some help with this guys!!

 

[chip]

Old thread I know but mine is throwing the same codes.....but I think the reason is because I am putting too much amperage on the battery...what do you guys think??? I really need some help with this guys!!

Clean the throttle body first. Why do you suspect the Alternator?

 

[03tahoe2012]

Well I have 3 30amp relays for the hids and the power cable with an 80?amp fuse for the subs.....I just don't know what I'm doing wrong......I'm getting so frustrated im about to rip all of the wiring out and start new.....

 

[chip]

Well I have 3 30amp relays for the hids and the power cable with an 80?amp fuse for the subs.....I just don't know what I'm doing wrong......I'm getting so frustrated im about to rip all of the wiring out and start new.....

Relax. One things has nothing to do with the other. It sounds like you're stressing yourself out. That never helps, trust me.

If you're in cold weather (and getting the "reduced engine power" issue), you need to clean the throttle body, because it's sticking. It has nothing to do with any wiring. If you have wiring issues, that's something different.

Disconnect the battery, clean the throttle body really well, re-connect the battery, fire it up. You should be good. Let me know.

 

[buzzsaw714]

The only times I had "reduce engine power" and lose all throttle response was right after my custom tune. I had to reset the timing and have a few things tweeked before it stopped doing it. i'd start there

 

[03tahoe2012]

Naw it's not cold weather....plus I cleaned the throttle body like a month ago

 

[KRAWSH]

I don't have a pic, but it is on the side of the throttle pedal, when you order one you get the pedal and plug as an assembly.

Unless you have Adjustable Pedals. You can simply swap out the sensor. Non adjustable pedals are sold as an entire assembly with the pedal itself & cost about three times as much.

 

[KRAWSH]

I don't have a pic, but it is on the side of the throttle pedal, when you order one you get the pedal and plug as an assembly.

I've been suffering with this same issue. Its sporadic and never consistent. I was told Throttle Control Module could be faulty and needs to be reprogrammed or buy a used one and reprogram it. Located on LH Firewall. Black box two plugs just under the Hood Hinge. Just havent found a place that does this in Houston yet...

 

[KRAWSH]

I replaced my APP sensor, cleaned both Throttle Body and MAF and I still get Reduced Engine Power(Cleaning helped a lot less frequent now). It is sporadic and no real trend as to when it does it. Ive read tons of different things as to what it could be from faulty ground on the block, throttle control module(mounted LH firewall) and possibly the Throttle Body itself. Ive purchased used TCM but truck would only idle. Dealer wants $115 to reprogram. When it the chime goes off I simply turn the vehicle off and restart and more often than not it works fine until it comes on again. Sometimes immediately. Others times it works fine for days. Can anyone shed light on this... where should i start?! Thanks in advance.

 

[Maximus1]

I'm in the same boat. 2004 Tahoe 5.3 Flex fuel. Replaced grounds, replace TAC module, cleaned throttle body, replaced both the TPS sensor and pedal sensors twice. I STILL HAVE the reduced engine power. Codes U0107 P1526 and a third that I can't remember also today my ABS light came on. I'm going to replace the whole throttle body next and if that doesn't work then I'm replacing the ECM unless someone else has a better idea.