[2drtahoe4x4]

Have a 97 tahoe with a 4l60e transmission with less then 10,000 miles on it. It was a reman from GM. Only code I'm getting is the p1860 one. It sets with in a few seconds of being cleared no driving needed. Driving me nuts trying to figure out what it is. Dropped the pan and tested the tcc solenoid. It did seem to be stuck closed at first so I thought that was the problem. Reinstalled it and same code all over again. Any trouble shooting list or ideas would be greatly appreciated. Thanks in advance,
Matt

[joshp83]

ignition switch most likely check fuse that powers the trans first

[LATECH]

The solenoid should have a resistance of 10-16 ohms.
Be sure the trans fuse is not blown.If it is then there is a short to ground which may be intermittent .
Could also be short or open in wiring from PCM to solenoid
PCM could be faulty

[2drtahoe4x4]

Wouldn't the ignition cause more problems then just the p1860 code? If not is there a way I can test to see if its good or bad? Trans fuse is good. I'll check the solenoid tomorrow. If that's good I guess its onto checking wires. Thanks for the quick replies.

[joshp83]

only 2 symptoms occur intermittant hard starting and fuel gauge acting wierd the switch controlls current to the ecm. most gm vehicals that come to my shop with a 1860 code it is in the ignition switch not the lock were the key goes the switch is on th e bottom of the column but check basics fuse and trace the wiring

[2drtahoe4x4]

Originally Posted by joshp83

only 2 symptoms occur intermittant hard starting and fuel gauge acting wierd the switch controlls current to the ecm. most gm vehicals that come to my shop with a 1860 code it is in the ignition switch not the lock were the key goes the switch is on th e bottom of the column but check basics fuse and trace the wiring

Sorry for the misunderstanding. Could you please elaborate on this switch as I'm not familiar with it. So if you could let me know what I'm looking for and how to test it that would be great. I traced the tcc pwm solenoid wiring back to the computer and when I unplug and ground it the solenoid works. So maybe a problem in the pcm? Thanks again for all the help.

[66GMC]

Originally Posted by 2drtahoe4x4

Sorry for the misunderstanding. Could you please elaborate on this switch as I'm not familiar with it. So if you could let me know what I'm looking for and how to test it that would be great. I traced the tcc pwm solenoid wiring back to the computer and when I unplug and ground it the solenoid works. So maybe a problem in the pcm? Thanks again for all the help.

NAPA Echlin # KS6201

This what the ignition switch should look like. It's not the type mounted down the column, and controlled by a rod.

I almost hope this isn't your problem, because it retails for about $400.00 here in Alberta Canada.

[2drtahoe4x4]

Any advice on trouble shooting the ignition switch?

[2drtahoe4x4]

Just and update for anyone who was following or may be having the same problem. Got a used re flashed PCM to my VIN number and the problem seems to be fixed. Thanks for all the help everyone.