Lost TCC lock up when MAF enabled
Thread Starter
Joined: Nov 2008
Posts: 2,423
Likes: 225
From: A-Town, Ill side
Lost TCC lock up when MAF enabled So I have a similar thread in the trans section, because I wasn't sure where I wanted/needed to post this, but here it goes:
The long and short is if I take a tune that I have in my truck with the MAF failed at 0hz, turn that on to fail at 13,500 and load it, I loose my TCC lockup in 3rd and 4th gear. I have tried this 3 different times. That is the only change made to that particular tune.
Has anyone had or seen this particular issue? If I go in and force the tcc to lock up with the MAF on, it will in HP Tuners, but it will not lock up on its own as the tune tells it to.
The long and short is if I take a tune that I have in my truck with the MAF failed at 0hz, turn that on to fail at 13,500 and load it, I loose my TCC lockup in 3rd and 4th gear. I have tried this 3 different times. That is the only change made to that particular tune.
Has anyone had or seen this particular issue? If I go in and force the tcc to lock up with the MAF on, it will in HP Tuners, but it will not lock up on its own as the tune tells it to.
Teching In
Joined: Mar 2015
Posts: 45
Likes: 0
From: Houston, Tx
Can you log the TCC lockup channels? TCC misfire and fault would be the ones to look for. I do think it's odd that changing only that one thing is making the converter act funny, but I wouldn't put it past a misfire to make the TC act funny. If the TCC misfire status is flagged ("YES") then that's why it's not locking. If that's the case then loosen up your misfire detection in the engine dtc page.
edit- I double checked and yes, for sure, when in SD the trans tables ignore the misfire detection tables. When in MAF then they sanity check against the misfire tables (for some stupid reason). Loosen up your misfire tables and you'll be set.
edit- I double checked and yes, for sure, when in SD the trans tables ignore the misfire detection tables. When in MAF then they sanity check against the misfire tables (for some stupid reason). Loosen up your misfire tables and you'll be set.
Thread Starter
Joined: Nov 2008
Posts: 2,423
Likes: 225
From: A-Town, Ill side
Thanks so much for the input! I will double check that. I thought I had misfire off completely, but I can't say 100% without looking. It may just be loosened up. I was told when I was trained, that a cam will cause misfires, and it's best to just turn it off unless there is a problem your chasing. I will certainly look, because so far, I am thrown for a loop.
Teching In
Joined: Mar 2015
Posts: 45
Likes: 0
From: Houston, Tx
If you post your tune I could take a look. For sure, log those channels I said earlier, as that’d tell you for sure, but even if you loosened them up it wouldn’t throw a CEL without setting several different flags first. In order to throw a CEL it would have to have a “misfire” in a steady state, several times, within a certain time limit. Even if you loosen them up it’s possible for it to have a pending code the entire time you’re driving it around and not throw the light up.
Edit- Yesterday we had a car come back from the tuners that we did a head/cam/nitrous setup on. Turns out that the tuner had bounced it off the rev limiter really hard on accident and one of the rockers had come off the valve. The bolt was still tight in the head, the rocker had just been bumped off. That misfire obviously wouldn't be intermittent, but the CEL was intermittent. It would go away when you revved it for a second but come back after a couple seconds of idle. It ran like crap, obviously, but the light itself would come on and off even though there's no possible way the misfire was coming and going.
Edit- Yesterday we had a car come back from the tuners that we did a head/cam/nitrous setup on. Turns out that the tuner had bounced it off the rev limiter really hard on accident and one of the rockers had come off the valve. The bolt was still tight in the head, the rocker had just been bumped off. That misfire obviously wouldn't be intermittent, but the CEL was intermittent. It would go away when you revved it for a second but come back after a couple seconds of idle. It ran like crap, obviously, but the light itself would come on and off even though there's no possible way the misfire was coming and going.
Last edited by 07V; Mar 22, 2018 at 02:39 PM.
Thread Starter
Joined: Nov 2008
Posts: 2,423
Likes: 225
From: A-Town, Ill side
I am going to build a few scanner setups today. I did check the tune and I have the mis fires maxed out. I checked and do not have any codes pending or active, short of the MAF when it is off for SD. Here is the tune. Thanks!
