Tow/Haul switch

[Iracea911]

Ive noticed a few tow/haul threads recently. My question doesn't fall into any of the previously asked questions.

I think the momentary switch on the end of the gear selector shaft is failing, or there is an open in the somewhere else in the circuit that isn't constant.

The reason I think this is, sometimes I select "tow/haul" mode, by pressing the switch, and the trans does not go into tow/haul mode, and the tow/haul lamp doesn't illuminate. In other instances, I hit the switch and the lamp lights, and the trans behaves as it should.

Is the switch easily replaceable?

Should I look for faults anywhere else?

If I bring the truck to the dealer will they be able to find this fault using the scanner, or actually will I be able to find the fault using a scanner? I have access to a shop where we buil racecars, and have OBDll scanners , etc available..

[GregH]

The scanner required for this truck needs to be CAN compliant. Most generic OBDII scanners won't communicate.

As for the switch failing, it does happen. You would need to replace the gearshift lever. It's an easy job - no special tools required.

Take a close look at the harness where it routes over the steering column. I've seen a few that have rubbed through and are shorting intermittantly on the column. Although this usually results in blowing the fuse for the tow/haul switch. This also feeds the idle validation switch, and the engine will only operate at idle...