P0742 no symptoms

[N2BRK]

I had the weirdest thing. I was sitting in my truck waiting and got bored and played with my Edge monitor. I had no MIL and no symptoms but I hit read DTC's and out popped a P0742! The truck feels just fine and I had no reason to suspect an issue. I couldn't clear the code with the Edge, so I hooked up the V2 and cleared the code. It hasn't returned, but I'm going to keep an eye out.

Is there anything to do as PM in case there's an issue about to pop? I'm guessing something like buying a new solenoid or valve to keep on hand? Or would a log show a lag in unlocking or something?

Thoughts?

Thanks in advance!
Wally

 

[Mike L.]

P0742 means the converter clutch is dragging or not releasing. Rarely will a F trim solenoid do that. More likely a sticking converter flow valve or a damaged converter.

 

[N2BRK]

any way to diagnose without remove/inspect? Thank you!

 

[Mike L.]

any way to diagnose without remove/inspect? Thank you!

Hook up a Tech2 and watch the turbine speed sensor. It must come to zero when coming to a stop. It should do that quickly. If it lags going to zero, the converter clutch is dragging.

 

[N2BRK]

Thank you!

 

[N2BRK]

just thinking out loud and wondering... why didn't I get an accompanying P0700 and a MIL? I do have a BT Lockbox if that could have anything to do with this oddity.

 

[Mike L.]

just thinking out loud and wondering... why didn't I get an accompanying P0700 and a MIL? I do have a BT Lockbox if that could have anything to do with this oddity.

Yes it can.

 

[N2BRK]

Since I have no symptoms, I'll wager that's the reason. I'll still do the logging as you prescribed - thanks again!

 

[N2BRK]

I got a shift range inhibited message and the code came back today Looks like it wasn't a fluke.

 

[Mike L.]

I got a shift range inhibited message and the code came back today Looks like it wasn't a fluke.

If the turbine sensor does not go to zero when the truck is standing still in gear, you will get Shift range inhibit. The TCM must see a gear pull down at a stop or it will throw the code. It appears your TCM is still seeing rpm's at the turbine sensor at stand still.

 

[N2BRK]

I'll log it again, but when I logged last time it was dropping right down... which caused me to suspect it was possibly the lockbox. I'll log again. Thanks Mike!

 

[N2BRK]

I checked again with what I have (Edge Box, code reader, and Efilive V2). Just like last time, the Edge is the only reader that shows the DTC! EFI Live doesn't even pick it up. No CEL and no freeze-frame data. I put in a call to my buddy for a better scanner and hopefully some insight. Maybe this converter is already going tits up? Ugh.

My wife's fish tank leaked this morning and I've spent all day taking care of that crap. New 150gal tank and all the fish are presently alive... so other than my wallet being light and my frustration level high between that and this issue, at least I'm not in trouble today, LOL. Well maybe not for a few minutes today, I don't want to overstate my hand.

 

[WVRigrat05]

I've been very very mean to my ML converter, I'd be surprised if it's bad, mine hates staying locked, if yours is sticking I'll trade ya, haha.

 

[Mike L.]

I'll log it again, but when I logged last time it was dropping right down... which caused me to suspect it was possibly the lockbox. I'll log again. Thanks Mike!

I thought you already disconnected it. Disconnect the box and clear the code. See what happens.

 

[N2BRK]

No I just cleared the code last time. I'll disconnect it tomorrow. The truck can't get out of its own way without it, lol.

It's not an ML. I was told that it's similar though. George thought it would be good for the stg2r but without the box it's awful with this setup. Might be great in a stock truck though?

 

[WVRigrat05]

No I just cleared the code last time. I'll disconnect it tomorrow. The truck can't get out of its own way without it, lol.

It's not an ML. I was told that it's similar though. George thought it would be good for the stg2r but without the box it's awful with this setup. Might be great in a stock truck though?

I have the ML, it clicks right along on anything 120 hp and under, 175 and 230 you really have to beat the shit out of it for a few take offs to want to lock up in 3rd. If you baby it for days and days and punch it one time it's lost in a goats ass, I've just relied on tow/haul like always and it works most times.