Hi all,

Sunday as I was leaving town and as I got on the highway it would not drop into Overdrive on my 2004 Chevy Colorado and it has 461,500 miles and it has been running perfect until Sunday morning so I turned around and threw all my shit in the Rat and left.

Had the tranny fluid sucked out a few weeks ago and its been shiting perfect!

Here are some ideas I found from other Colorado owners having the same issue and plus the cruise control did not work either and prior it worked!

Hey folks. Long time reader, first time poster. First, thank you for all the previous help with all the forum posts.

Here's my predicament. For the last two months my truck would occasionally not lockup in fourth gear. The funny part is whenever this happens the cruise control also does not work. To add to the confusion every once in a while when driving at highway speeds the doors will lock, the torque converter will lock up and then the cruise works again.

Now the tranny doesn't lock up at all. Any suggestions?

2004 Canyon
3.5L I5 Crew Cab 2WD
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post #2 of 12 (permalink) Old 11-06-2014, 05:36 PM
WDEagle
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Tranny part is confusing but ...

When the cruise does not work, it is often a bad brake switch. When your cruise is not working, look and see if your brake lights are working. If not, it's probably a bad brake switch. Cheap to fix.
War Dang Eagle !!!

2016 Lazer Blue Long Bed Crew Cab
2004 Black ZQ8 Crew Cab <---Sold

Cut the Dang Wire Already!!!!!!!!!!!!!!!!!!!!
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post #3 of 12 (permalink) Old 11-06-2014, 05:58 PM Thread Starter
Jonx
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Thanks WDEagle. The brake lights work fine. I went out and checked again to make sure. Too bad, that would have been a nice fix.
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post #4 of 12 (permalink) Old 11-06-2014, 07:37 PM
cart7881
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to C'Fans.

The failure of the cruise control and the transmission converter lockup are probably related. Mounted on the brake pedal bracket, next to the brake light switch, there is a switch called the TCC Brake/Cruise Switch. TCC meaning:Torque Converter Clutch.

Item #6 here: BRAKE PEDAL MOUNTING | Nalley Buick GMC Brunswick

Power to the switch is from the cruise control fuse. The switch is connected to the PCM which monitors and controls the cruise control and the transmission. How this switch is related to the TCC is unclear, however it does affect the operation of the cruise control. It is closed when the brakes are off and open when the brakes are applied. If this switch gets stuck open, the cruise will not operate.

The door locking is a different problem. The doors don't lock when you put the truck in gear?
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post #5 of 12 (permalink) Old 11-07-2014, 10:25 AM Thread Starter
Jonx
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Wow! I had no idea a switch by my brake pedal would stop my overdrive from locking up. Seems weird. On a very positive note, I reached under the dash this morning and gave the switch a good wiggle and pressed the plunger in and out a few times for good measure. On the ride in, it shifted flawlessly. I'll be picking up a new switch this weekend. Thank you very much.

The door locks stopped locking a while back. I didn't really care as my boys are old enough not to play with the door handles. Not to mention I hate locks. I seldom if ever lock my doors.
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post #6 of 12 (permalink) Old 11-07-2014, 11:26 AM
cart7881
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I'm not sure that the switch in question would affect the converter lockup. The Service Manual is not clear regarding the association of that switch with the transmission. There is no doubt that it affects the operation of the cruise control. Let us know what happens with the transmission after you replace the switch.
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post #7 of 12 (permalink) Old 11-12-2014, 08:51 PM Thread Starter
Jonx
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So I took off the switch in question to bring it in and make sure I had the right part when I replaced it. After a little inspecting I saw one of the contacts was filthy. A little rubbing alcohol and a q-tip and it was good as new. I re-installed the switch and it has been running fantastic. It shifts great and the cruise control works consistently. Thank you everyone for the help. Now I should look into the door locks (but probably won't because I never lock the doors anyhow!)

Thanks again!!
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post #8 of 12 (permalink) Old 07-20-2015, 11:21 AM
topps
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That was my problem. I depressed my brake pedal and flicked the switch once or twice. Now my cruise and brake lights function. Now if it goes out again, which of the two switches that operate with brake pedal is the culprit?
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post #9 of 12 (permalink) Old 07-20-2015, 12:57 PM
cart7881
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Do you have the same problem as the OP, i.e. the torque converter not locking, or just a cruise control issue? Both of the switches, if defective, can cause the cruise to be inoperative. The switch that causes most of the problems is the brake light switch. That switch can be checked easily by verifying whether or not your brake lights are working.
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post #10 of 12 (permalink) Old 07-26-2015, 02:37 PM
topps
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Yes whether brake lights are working is how I check to see if cruise is working before I drive. The switch has stuck again a time or two. When cruise is not engaging, I hit the brake pedal a time or two and then the cruise works. How can cruise be both brake pedal switches? That seems like too much circuitry and logic for GM to put it on both switches. Also I would like a comment on how the poster above cleaned the switches to get them functioning again. They look enclosed to me when looking under the dash.
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post #11 of 12 (permalink) Old 07-26-2015, 02:38 PM
topps
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Do the switches on brake pedal bracket have open contacts? Mine look enclosed when glancing under the dash.
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post #12 of 12 (permalink) Old 07-26-2015, 05:20 PM
cart7881
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This is a copy/paste from the Manual under "Disengage": "The TCC brake/cruise release switch and the stop lamp switch are mounted on the brake pedal bracket. When the brake pedal is applied, the normally closed TCC brake/cruise release switch opens and the normally open stop lamp switch closes. The PCM detects a low signal voltage on the TCC brake/cruise release switch signal circuit and a high signal voltage on the stop lamp switch signal circuit. When the clutch pedal is applied, the normally closed clutch release switch opens and the PCM detects zero voltage on the CCP switch signal circuit. The vehicle speed stored in the memory of the PCM will be erased when the cruise control On/Off button is turned OFF, or the ignition switch is turned OFF."

I haven't done a closeup inspection of the switches. You would probably need to remove it/them to determine if cleaning is an option for you, as mentioned by Jonx. To remove the switch, just disconnect the connector and turn the switch to the left to unlock it. Both switches are mounted the same. CAUTION!!! When reinstalling the switch, hold the brake pedal all the way aft (toward the steering wheel), while you insert the switch as far as it will go and turn it to the right to lock it. Failure to hold the brake pedal all the way aft, can result in the switch being adjusted too far in and holding the brakes in a partially applied position, resulting in brake drag.