Tow/haul Not Working

MikeNH · September 3, 2014

Not the steering column switch or harness. Check them visibly and with continuity light. Tell me more about the brake pedal switch. Is it part of the stop light switch or a separate device? When I push on the tow haul button the indicator on the cluster is on but it has no effect on the transmission. Loaded or unloaded at any speed. It hasn't worked since I got the truck. The dealer said it is just fine. Quote .."It is operating within the parameters set by GM for that truck that year" I have driven other 09 Silverado's and they work just fine. Mine is a 1500 WT 4.8. Did GM tamper with them in an effort to raise fleet mileage numbers or for some other reason. If so what can be done? I bought this truck to tow an RV so the tow haul is important. Thanks..Ziffel

Real world mileage doesn't matter to GM. For what it's worth, tow/haul is much less obvious in my 2011 than my 2003 was.

ziffel · September 3, 2014

Thanks, Do you know if the sensitivity of the Tow Haul can be adjusted up and down and how is it done. Is it something I can Do? I am used to my 99 Silverado. It works very well. This one has never worked. Thanks Ziffel

ziffel · October 7, 2014

Got truck back from dealer. After extensive testing and a call or two to GM Engineering it has been decided that there isn't anything wrong with my truck. On the way from a dead stop using moderate throttle and with tow haul activated the 4L60E shifted thru all four gears and locked the converter. Doesn't seem right. Also noticed the converter doesn't unlock when tapping brake pedal. All fuses are good and the brake lights work. I was unable to find anything about it in the owners manual. My 99 does but I don't know if this 09 should. Thanks..Arnie

09 Silverado WT 4.8 4L60E manual transfer case. 3.42 gears and 18" tires. 66K

02suburbanZ71 · October 7, 2014

I thought that T/H locks out 4th gear?

Chris · October 8, 2014

I thought that T/H locks out 4th gear?

It does not. It avoids 4th unless conditions are right

ziffel · October 8, 2014

~~If the steering column wires are the problem; it also could be your brake pedal switch as well. They have been known to give out from time to time.~~

Totally disregard this post, I was thinking cruise control...brake light switch and tow/haul have nothing to do with each other...my apologies.

Doesn't stepping on the brake pedal unlock the convertor?

gmtech4 · October 8, 2014

Doesn't stepping on the brake pedal unlock the convertor?

yes but its not as obvious like ear;ier yrs where ya can see the 200 rpm jump ....its PWM now and that means its ramped up and ya dont feel it ,,,,

somebody needs to post a description and operation for the tow/haul system,,,i cant right now

ziffel · October 8, 2014

Evan if I can not feel the convertor unlocking, it should show on the tach. Also if I apply throttle should the RPM'''s rise until it relocks? Thanks Arnie

gmtech4 · October 9, 2014

the old days yes ,now ,not so much ,ya want to know ,? get a scanner and watch the data

Scsllc386 · November 12, 2015

My tow/haul light on dash comes on in park but after you put it in gear you can't shut it off or turn it on.

davester · November 12, 2015

My tow/haul light on dash comes on in park but after you put it in gear you can't shut it off or turn it on.

Weird. My '04 Sierra 3500 can switch on the fly, even at highway speed. And it actually switches gear, turning it on will generally make it downshift unless I'm going downhill, and then turning it off will shift back, at highway speeds.

Scsllc386 · November 12, 2015

Used to work the same as yours davester. If you put it in gear the light will not come on. Going to take the steering column apart tomorrow and see if the orange wire is broke. But if the wire is broke why does the light come on in park?

davester · November 12, 2015

shift lever moves the wiring harness in the steering column a bit, making/breaking the connection?

Scsllc386 · November 13, 2015

Thanks to everyone for your input. I've seen the orange wire broke in half before. Now I've heard the two wires in the orange insulation can actually be broken with no visually way to detect the break. So I am going to put the multi meter on it and check the leads to see what the continuity is and the resistance. I also have one more problem. My direction/temperature readout on my rearview mirror is not working. Everyone had great input on the tow/haul problem and made my life much easier. Hopefully someone has ran into my second problem also. Thanks to all of you.

06jimmy · November 21, 2015

I just bought a 06 Sierra and compared to other Chevy trucks I have owned with tow/haul option it seems odd the way it works. I thought at first it did not work at all, I would push it and indicator light would come on but nothing would happen ! Then I discovered it would only lock up at speeds of 50 mph or below and would automatically shift out at 58-59 mph on it own !

I had it in the Chevy dealer for a follow up on another subject and described it to the service writer, they drove it and said it worked correctly and they could not find a service adviser on tow/haul problems. And here I have read several different problems on them!

Can anyone tell me if the way mine works is correct or not !? I have had vehicles with tow/haul and they all pretty much engaged and stayed engaged until you would turn it off.