Uh oh.... 07 Silverado, issue....

[IDRIVEAG8GT]

Ok so I finished building the 6.2/427 yesterday, installed it into the truck today, and got it's first start in! It cold started no problem at all, and idled well, then all of the sudden at running temp the dash read out, "Reduced Engine Power" The idle dips to about 550 and keeps running, then just dies, and will not restart again.... So I went over everything and found that there is a wire that I forgot to connect on the backside of the engine. It's on the same wiring harness as the Oil Pressure Sending Unit plug, and is about 4 inches away from it. It has about a 5 inch lead and it is a 5 wire plug. It's black, and the dust boot's color is blue. Where the hell does it go?! Sorry to ask this on this forum but perhaps it could be tuning related. I probably would not be asking this question, but I was not the one who removed the standard 6.0L in the first place.... So through the whole build it has been meticulous trial and error.... Anyways, please, any help or suggestions would be greatly appreciated.

Thanks,
Robbie.

[DSteck]

Post up what codes were present. That'd be a start.

[IDRIVEAG8GT]

Post up what codes were present. That'd be a start.

There's one main one I know of (P0641). The plug, by the way, is for DOD thanks to my old Auto Tech teacher It was removed as this truck is currently running a ZR1 camshaft. So there's no reason for it to be used. And DOD is disabled in my tune. I need to perform a complete write, because if you recalibrate the truck, it will immediately send out the message "Reduced Engine Power" as soon as my laptop finishes writing the VCM....

[IDRIVEAG8GT]

By the way, if you get rid of DOD are you still supposed to hook up both wires that come off of the non DOD front plate? I couldn't find the harness for the two wire connector that comes off of the bracket.... So I simply tucked it up out of the way and plugged in the main connector.... P0641 though... Sensor Circuit A? Any takers?

[IDRIVEAG8GT]

Found the problem! and truck is home! Oil Pressure Sending Unit was bad, and yes the five volt reference is exactly right. Thanks for the suggestions guys! BTW DSteck, saw your Z06 on Youtube. Very nice OK so now that all that is over with, I pretty much uploaded a ZR1 tune, minus the MAF calibration, and it seems to like it, but here's the weird thing. It has a hard time recovering from being revved.... As in it wants to stay at 1200 RPM after being revved until it backs loads of timing out of it and it comes down to 650 RPM. And, when you put the truck in gear and let off the brakes, it will idle itself back up to 1200 RPM. And coasting? Haha it's like you set the cruise control. Is this tuning related, because of a tight engine, or maybe a vacuum leak? Never had this issue before. Oh and no error codes. Thanks for the help and suggestions, c.u. and Steck.

[IDRIVEAG8GT]

Um guys....? Confused? Dunno what the hell the truck is doing? BUMP* TPS is slow to reduce itself from 24% to 21% so it will idle as commanded! AGH? WTF?

[Mep_q8]

wat was the motor in it before? what have u set for the ETC scaler?

[DSteck]

Back off the minimum idle airflow. That's what is causing your high idle and cruise control effect, most likely.

[IDRIVEAG8GT]

Originally it was a Magnacharged L76. Custom tune. Now it is a 6.2/427, same MP 1900 Maggie. The throttle body is the same off of the L76 too, and on this engine it responds differently. Thanks Steck, I'll try that. Shall I post a log?

[IDRIVEAG8GT]

Never mind! That was the fix! Thanks Steck! Now on to some more aggressive tuning

[94guy]

how do you check the five volt reference for the oil pressure sending unit? this is on a 2010 camaro.

[IDRIVEAG8GT]

It's easy, if you have a bad five volt reference signal somewhere along the line of the units mentioned above, the vehicle would automatically throw a Limp Home mode code and also another code pointing in somewhere of the direction of where it's losing five volts at. Also most units are monitored by gauges so your gauge on fuel tank, water temp, oil pressure, etc. It'd also show up if you were making a log of all that crap.