reduced power mode
 

I just finished swapping an 06 L33 and 4L60E into my '64 and finally got to drive my truck, but when I hit the gas pedal, the truck goes into reduced power mode. It is fine when I have it in park or neutral, it idles perfect and rev's perfect, only when I am driving will the truck go into limp mode. The only codes I've gotten are P0650 and U0107. I replaced the throttle body, TPS and double checked all the wires and grounds. Figured the new throttle body and TPS would fix it, but doesn't seem to have an effect.

I recently changed tire sizes from 275/65/15 (which the computer was programmed to) to a 265/35/22 and haven't flashed the computer yet. Is it possible that the difference in OD in the tires is causing the problem? I was going to throw the old wheels and tires on to see, but they're in storage now and haven't been able to get them.....

any thoughts would be appreciated, thanks!

Re: reduced power mode
 

The U0107 is the code for reduced power, so its telling you something you already know. Its something you'll see from low voltage (so make sure your not just running of Alt power). Also make sure you don't have damaged or pinched wires on the throttle pedal and Tac module. Make sure the plugs on the TAC unit are fully insterted and clicked in.

The other code is the MIL control circuit. I'm not super familiar with that code, but I believe its the circuit that runs the idiot light, and also goes to the gauges and BCM. If your not running the o.e gauges and BCM stuff, this shouldn't be causing your problem.

Re: reduced power mode
 

What I do and suggest to others is you have LS wiring issues is to go over your harness with a "fine tooth comb"- in other words, disconnect and inspect every connection and:

check grounds

double check grounds

Its usually a ground issue on LS wiring complications IME

Re: reduced power mode
 

Are you certain you have the correct pedal for the file in the PCM?

Re: reduced power mode
 

Pedal and tach module have to match.

Re: reduced power mode
 

what's the 'cold air set up'? we had a GTO that would do this, after all the changes to the PCM/etc it would still do it. come to find out the blade was catching on the MAF/coupler, changed that up and all was fine! so look at that area.

Re: reduced power mode
 

Is the traction control input wire removed from the PCM? What ecu are you running, e40, e38 or p59?

Re: reduced power mode
 

i asked this question to the company who did my tune and it sounds like they had an 03 to 05 tune on the PCM which is different than the 06 with the plastic pedal. i sent my PCM back to them to have it re-tuned.

i just sent another e-mail asking these two questions.

thank you for the input!

Re: reduced power mode
 

i put a Spectre cold air kit on it. are you referring to the blade on the throttle body?

Re: reduced power mode
 

i went through my wiring again and found that i had the wiring for the TCC brake switch mixed up, so i swapped it and it cleared the MIL code!

Re: reduced power mode
 

I received and installed the re-tuned PCM from the vendor today and the problem is fixed! They had the wrong pedal on file like was suggested. I just want to thank everyone for responding and helping me get this figured out!

Re: reduced power mode
 

:thumbs: