Back in May my truck suddenly died when coming to a quick stop. It did it two more times that trip and since then when the truck is hot (not overheating), when the temp outside is hot (here in Texas) it will die while braking to a stop almost without fail - after running about 30+ miles. Also, lately the transmission will do occasional hard shifts at unexpected times and I also hear some knocking or plinking noises at times under the undercarriage while driving. Another thing is the idle seems very low - around 550 at a dead stop whenever it doesn't die. Any ideas? It's not putting out any codes and all systems seem normal. I'm thinking either a throttle position sensor or a vacuum line issue to the transmission.

 

Plugs, wires, coil packs need replaced?

 

Continue checking for codes...could be the following:

• A throttle position sensor
• A bad IAC valve.
• Also make sure your MAF sensor is not coated in gunk.

When was the last time you changed your fuel filter?

 

Time to clean the TB and IAC valve.

 

I changed the fuel filter about a month ago - attempting to stop this problem. It was very gunky, but didn't stop it. I'm taking it in the shop today since I have an extended service plan on it. My dealer is pretty good if you can fight through their tendency to try to sell you on stuff.

 

Let us know what you find out. It could have some tranny codes. Not all scan tools will access tranny codes. It could possibly a torque converter problem also.

 

Well. The dealership called. Service Advisor said they can't get the truck to duplicate the problem - and, as I said before, it's not throwing any codes. I guess I'll go pick it up and just try to work on it myself.

 

dude try and clean the throttle body with tb cleaner and wipe it out take the tube off i had the same problem with my o6 the airbox was cracked on the bottom letting dirt and dust in take the intake tube off and sray away and wipe out cause it gunked mine all up .

 

The dealer let me have the truck with a "flight recorder" installed on it. All I had to do is press a button when the problem occured. Two days later it did and I pressed the button. This time the truck actually had the check engine light on aso I knew a code was registered. I was 35 miles from the dealer, but I drove straight there and turned the truck over to them. They ended up replacing the throttle body and I was happy, but two days ago the truck died on me again and then the next day the transmission was acting up in cruise control - several little hitches or jumps at a time. I guess I'll have to take it back.

 

I don't know if you would get a code or not, but it could be the tourque converter not unlocking. That would be just like stoping a vehicle with a manual transmission and not disengaging the clutch.

 

Torque converter not properly unlocking should throw a code. That's what it sounds like it could be to me.

 

I 've been saying its like trying to pull up to a stop sign in fourth gear without pushing the clutch in - it dies like that.

 

Okay. I think it's fixed now. After putting it in the shop for the third time, same problem the mechanic found a wiring harness that was pinched in between an A/C line and the valve cover and had rubbed throught the protective sleeve covering the harness and had rubbed through the wire pair that goes to the "crank position sensor" or "crankshaft position sensor". Apparently the cold A/C line in hot weather condensed enough moisture in hot weather that it grounded the wire and would cause the problem. I'll be driving a lot this week and will know if it got fixed.