Tow/Haul won't engage

[Boz86]

This seems to be a common problem based on all the videos out there.

There's a wire that runs inside the transmission shift lever from the button. As it comes out of the lever it goes under the steering column and to a connector on the left side. That wire gets pinched sometimes and fails or it flexes every time you move the lever, and eventually many fail.

The button on mine quit engaging the tow/haul mode. I didn't have a good enough scanner to see if the button was sending a signal to the transmission or if I just had a burnt out dash light. It didn't feel like the transmission was changing but that was just a feel.

Rather than pull out the parts cannon I followed the videos and disassembled the dash. The wires weren't broken that I could see with the lever in the truck. I disconnected the wire from the connector.

With a bent paper clip and the key on I jumpered the engine/transmission side of the connector momentarily. Light came on. Jumpered it again, light went out. Continuity check on the lever button failed.

New lever fixed it, but I liked narrowing the problem to the lever before spending money on it. If this was a farm truck or just my beater I'd fix it differently but I went with an OEM replacement.

The truck side of the connector I jumpered:

The broken wire I couldn't see until I pulled the lever out:

 

[Big Mama]

Nice. Do you think it breaks as a result of using the tilt wheel or ? I haven’t had this yet but I’m sure it coming.

 

[Rocket Man]

Mine broke a little further down from the lever. I soldered and used heat shrink on it.

 

[Joseph Garcia]

Thank you for your detailed description and pics. Much appreciated. Our collective knowledge base has been increased.

 

[Mudsport96]

Had this happen on my dads 02 Sierra HD, i hit the junkyard for a good lever so i had plenty of wire and the connector. Disassembled new shifter and removed the wiring, then since his fog lights were broken and he wasn't replacing them, i wired to the fog light button since it is also a momentary button. Marked it tow/haul with a lable maker and away he went. 10 years and even the new owner had no issues with it. The way it should have been from the factory with no moving wires to break

 

[Doubeleive]

ya you can do what you did or just use a meter on the wire out of the shifter has continuity when you press and hold the button.

 

[Boz86]

Nice. Do you think it breaks as a result of using the tilt wheel or ? I haven’t had this yet but I’m sure it coming.

I read that it can either be pinched with the tilt or it just fatigues from working the shift lever.

 

[Boz86]

ya you can do what you did or just use a meter on the wire out of the shifter has continuity when you press and hold the button.

I did a continuity check on the old lever before pulling it. The jumping to activate just verified everything else seemed operational. Maybe overkill but it's easier IMHO to jump that one harness than try to hold the multimeter leads while pushing the button (probably an amateur error....).
If I could have seen the break in the wire I wouldn't have done any of this.

 

[Big Mama]

I read that it can either be pinched with the tilt or it just fatigues from working the shift lever.

thanks for clarification. I use my tilt constantly so I’ll have a look.

 

[bigdog9191999]

yep have had to fix that in a couple, thankfully the switch has always been good so reconnect and on my way. but I need to do my suburban ( not that I need it much with the 8.1 and 4.10's) and am considering doing a dash mounted push button instead of the shifter.