Random tc lock
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From: Las vegas
Random tc lock
My torque converter started locking and unlocking at random while driving it seems to mostly do it when i hit bumps also some times while coming to a stop it stays on untill i hit the brakes.
I checked the flps and the signal was smoth even when i tapped on the side of it any ideas?
I checked the flps and the signal was smoth even when i tapped on the side of it any ideas?
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From: Las vegas
I've been driving around for a while with my manuale TC lock swich and TC lock LED un hooked and at first it seemed to not do it as much and now it seems to have stop????????This is how i wired it, I dont see how it could cause this. Maybe its harder to notice with out the light flashing.
Lead Driver
Joined: Nov 2003
Posts: 6,900
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From: Campbell River, B.C.
The switch by the master cylinder; If we are thinking about the same thing, than that is the switch that activates the brake warning light in the event of fuid loss from the hydraulic system. No relation to the transmission as far as I know.
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From: Las vegas
So the swich for the lights, tc and brake controller are all the same one is it on the pedal? I thought the brake warning light was activated by loss of vacume, I dont have hydoboost/max, the swich I'm thinking of is in the brake line I think I will have to go look at it I may be thinking of my budies F150 that had the brake swich for the cruse controll in the brake line, but I'll have to go look at it tomarow.
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Lead Driver
Joined: Nov 2003
Posts: 6,900
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From: Campbell River, B.C.
You have the brake light com on from the E-brake being applied, from low vacuum, or from a low hudraulic pressure in the brake system. If you have a brake line burst (see that often with all the rust that happens up here) and the pressure drops, the light comes on, the switch that controls that warning is located at the master cylinder. Both my trucks are vacuum boost and they each have it. And they have each popped the rear lines at one time or another
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And yes, the switch at the pedal should be one and the same.
.And yes, the switch at the pedal should be one and the same.
Fleet Mechanic
Joined: Sep 2005
Posts: 1,509
Likes: 3
From: Ladner, British Columbia
Brake Light Swith
From everything I have read above I would agree, check or better yet replace your brake light switch above the brake pedal.
My dad had the same problem with the OD going in and out and it turned out in the end that the brake light switch was coming in and out intermittently.
Note you need to fix this as not only is the OD coming in and out but other gears are shifting funny which is burning up your clutches in the tranny. I had changed the oil not long before the trouble with the OD coming in and out started and the oil was already burnt again. Once I changed the switch all went back to normal.
The tranny controller uses the signal from the brake switch to control shifting. The OD is supposed to drop out when you apply the brake under normal operation.
A last note, faulty trailer wiring will also give you trouble if it in any way affects the brake light circuit.
Best of luck,
Seb...
My dad had the same problem with the OD going in and out and it turned out in the end that the brake light switch was coming in and out intermittently.
Note you need to fix this as not only is the OD coming in and out but other gears are shifting funny which is burning up your clutches in the tranny. I had changed the oil not long before the trouble with the OD coming in and out started and the oil was already burnt again. Once I changed the switch all went back to normal.
The tranny controller uses the signal from the brake switch to control shifting. The OD is supposed to drop out when you apply the brake under normal operation.
A last note, faulty trailer wiring will also give you trouble if it in any way affects the brake light circuit.
Best of luck,
Seb...
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From: Las vegas
The one thing that makes me think it isn't the brakes it that some time when I let off the throtle it will unlock the tc then down shift and lock the tc untill I press the brake pedal also if I tap the throtle it will unlock it.
Also I think my brake controller might be junk the light stays on even when i unplug the brake swich. This weekend I'll check to see if it is getting a signal to turn the brakes on or not.
Thanks for the help.
Also I think my brake controller might be junk the light stays on even when i unplug the brake swich. This weekend I'll check to see if it is getting a signal to turn the brakes on or not.
Thanks for the help.
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From: Las vegas
Also another thought the brake light come on as soon as i put presure on the pedal so maybe when i hit bumps the pedal moves and the swich comes on is ther an adjustment for the swich?
And I forgot to mention occasinaly it will go to 3000rpm befor it shifts on light throtle.
And I forgot to mention occasinaly it will go to 3000rpm befor it shifts on light throtle.
Lead Driver
Joined: Nov 2003
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From: Campbell River, B.C.
Downshifting when you let off the throttle is not normal. Neither is upshifting at 3000 RPM under light load. Have you checked the FILP sensor? (throttle position) Ideally, you would check it with an analog multimeter, that way you can see if the reading is erratic across the throttle range.
Fleet Mechanic
Joined: Sep 2005
Posts: 1,509
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From: Ladner, British Columbia
OD in and Out
As a precaution I would also chance your ABS-speed sensor. For the 94 it should be located in your differencial. I had some build-up of metal shavings on the magnet once that caused all kinds of funny shifting. The sensor is really cheap and easy to replace.
I have been having trouble with my hazard light button (bad/loose contact) on my 93 (same as 94) and this again could interfere with your brake light circuit. Next time you use your hazard lights notice the truck will not shift into OD while the Hazard lights are on.
Seb.
I have been having trouble with my hazard light button (bad/loose contact) on my 93 (same as 94) and this again could interfere with your brake light circuit. Next time you use your hazard lights notice the truck will not shift into OD while the Hazard lights are on.
Seb.
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From: Las vegas
First thing I did was check the FLPS it showed good only thing I can think of is my blue point DMM isn't fast enough If I only had a scope. The FLPS is realy the only thing that seems to to fit in my head. If it is reading too high intermitently at idle the TC clutch will stay aplied until I hit the brakes if the signal drops on acceleration or cruise TC will dis engage also explanes late shifts.
Another thing I noticed today is the TC seems to come on and off at random more between 30-35MPH and isn't so bad between 40-45MPH but will stay on on decell at random.
Another thing I noticed today is the TC seems to come on and off at random more between 30-35MPH and isn't so bad between 40-45MPH but will stay on on decell at random.