Transmission/Alternator Relationship

2010 Toyota Tundra 2WD 8 Cylinders M 4.6L FI DOHC 281 CID, 99k miles

I'll be honest that I'm a rank amateur with vehicle mechanics, but recently had some issues with a truck that has been a champ for 5 years for me. Traction control light, check engine light came on at the same time. Ran the codes and they came back with stuck valve on Secondary Air Injection system and Rough Idle.

I hadn't noticed any rough idle issues, but I did notice a faint exhaust smell when I ran the heat/air after this came on.

My Secondary Air Injection System is getting fixed as I type this, but I was wondering specifically if the alternator might play into things. Alternator is putting out 13.2-13.4 V. Battery is good. I was wondering if the reduced voltage might be affecting the computer's communication with the transmission. I've noticed that when I accelerate gradually, and on flat/downhill sections of road, it shifts like normal, but if I am trying to accelerate uphill, that RPM's go way to high before it finally shifts. It's not always between the same gears either, so I'm less sure that it has to do with a mechanical transmission issue.

Any help would be greatly appreciated. I love this truck and was just getting ready to start saving for a new paint job and new interior.....

 

Corroded or loose connections to the battery can cause problems like this for sure. What code did you get for rough idle?

 

I’m sorry I don’t have the specific codes in front of me. Replaced the battery and the code for rough idle didn’t come back. The connectors looked good when we changed out the battery.

 

Sounds like to me that you're just experiencing the effects of "limp mode" that strikes when the AIP system fails. When mine failed, my truck shifted or failed to shift in a similar manner.

 

When mine had a stuck valve, it idled at 400 rpm, and driving to the farm, it would literally just die in the middle of town. No power steering, no power brakes, nothing. In town, middle of the street, people all around with engine dying= no bueno
Got er fixed up now though and runs like a charm... except the drivers side chain tensioner
Edit: I have a 5.7 by the way

 

"Secondary Air Injection system"
1.) the air pumps a there mainly for start up to reduce emissions till the rest of the emissions systems come up to operating temperature and can take over.

" Alternator is putting out 13.2-13.4 V. Battery is good"
2.) Alternator: as per Toyota for a Tundra from the service manual 13.2V-14.8V is standard operating voltage, on a cold start the Voltage will go up to compensate for the load till the battery is replenished. Or if the electrical demand going on is greater it will run a higher voltage to compensate.

"reduced voltage might be affecting the computer's communication"
3.) if the ECM was getting to low of volts there would be a mass of DTC's and multiple issues through out all the systems.

"I've noticed that when I accelerate gradually, and on flat/downhill sections of road, it shifts like normal, but if I am trying to accelerate uphill, that RPM's go way to high before it finally shifts. It's not always between the same gears either"
4.) (normal) Transmissions shift up gears when there is less combined rolling resistance, on a flat road or downhill its easier to get the vehicles mass moving witch in turn will allow the transmission to shift up into higher gears to keep RPMs down and be more efficient, while going up hill the vehicle must be able to sustain moving its mass thus the engine will increase RPMs making more power and over coming combined rolling resistance before shifting into a higher gear. (if it did not do that and just shifted up gears while going up a hill eventually it will start to slow down till the RPM drops so low and stalls the vehicle)

Conclusion
you have a stuck valve on Secondary Air Injection system and its getting fixed, while having a mechanical issue you have become hypersensitive (witch is normal)

also welcome to forum.