Engine/Transmission (1994 - 1998) No overdrive and no cruise control

[WadePatton]

Sorry, I've searched several time and I have to admit I still don't fully understand the seach engine here.







1995 RH Suncoast transmission. I've lost overdrive and noticed that cruise (I don't ever use) doesn't work. The flashing dash codes indicate, battery disconnected, short/open converter clutch circuit, and high/low voltage from transmission temp sensor. I forgot the nummers. transmission works fine in other gears AND lockup clutch works in normal postion and locks on demand via switch.



So I'm looking at transmission fluid/oil temp sensor and or speed sensor. Could the temp sensor affect the cruise? Is the speed sensor on the transmission? What's that thingy in the diff housing?



And parts numbers would be good. My guys are head scratching...

Thanks.

 

[SKnapp]

sounds like a tps or a short. on my first gen i had a bare wire @the back of enginealso caused the speedo to quit on that truck. just my 2 cents trying to help.

 

[BigPapa]

My money's on your brake pedal switch there Pres. Try taping something around the brake pedal where the switch makes contact to build it up. It doesn't need to be real thick, probably @ . 060-. 080" will do it. If that works, get you a new switch.



Scott

 

[WadePatton]

My money's on your brake pedal switch there Pres. Try taping something around the brake pedal where the switch makes contact to build it up. It doesn't need to be real thick, probably @ . 060-. 080" will do it. If that works, get you a new switch.



Scott

That makes some sense. I'll look into it.

 

[DRAG DIESEL]

Your code for short in the TC is from your switch. I'd be looking at the temp sender for the trans. I lost mine, same symptoms. But you could have 2 seperate issues. The trans will go into OD, even if the brake switch is depressed... but it wont lock up. I bypassed my temp sender with a resistor... that's what the gauges are for right?

 

[WadePatton]

Yeah, thas the ticket. I knew somebuddy would nail this one down. Yeah, I figgered out that the switch was my LU clutch code.



Be a day or two before I can fool with it again. Have two other trucks needing attention.

 

[wtfd6]

Your code for short in the TC is from your switch. I'd be looking at the temp sender for the trans. I lost mine, same symptoms. But you could have 2 seperate issues. The trans will go into OD, even if the brake switch is depressed... but it wont lock up. I bypassed my temp sender with a resistor... that's what the gauges are for right?

what resistance value did you use? thanks.

 

[Howard Durand]

Anything between 1000 and 5000 ohms would work fine.

 

[Joe G.]

wtfd6, the resister in place of the temp sensor applies to a 47RH transmission used on a '94 or '95.

 

[wtfd6]

oh ok. thanks. I was trying it on a 93. it has no o/d or lockup. actually the complaint was a delayed o/d and lockup. the engine mounted cooler has been bypassed. I guess it leaks. and they couldnt find a replacement.

 

[WadePatton]

Anything between 1000 and 5000 ohms would work fine.

As there are no electronics stores around here, I'm digging through power supplies and other junked out devices trying to dig up a resistor.



Hmm. . what about these big ones with numbers on them? I can read color band codes. This here writing isn't making much sense to me:-laf

 

[WadePatton]

okay, I gots a 1000omega and am going to try it here in a minute or two. report in a few.

 

[WadePatton]

That didn't work. The "tranmission temp" light came on(it hasn't been illuminated before--but did set a code) and it shifted as before 1. 2. 3.....

Is there some other value that I need to be concerned with on the resistor? I know the "tolerance" rating is irrelevant. #@$%!

 

[Joe G.]

If the transmission temp light came on the resistor was too high. You want a 1K not a 1M. I use a 750 ohm.

 

[WadePatton]

According to the bands, the resistor I used is 1K ohms +/- 10%



I suppose I'll have to BUZZ down to the big city. Or find some more components to shred.

 

[Joe G.]

Just checking. My 1K ohm bag of resistors has brown, black, red bands. The way to hook it up is to remove the connector and insert the resistor in the two cavities of the connector. Leave the temp sensor out of the hook up. The resistor fakes a reading from the temp sensor so it appears to be warmed up to operating temp but not too hot.

 

[WadePatton]

That's just how I did it. Cept I beefed up the "legs" of the resistor to fit the connector. Maybe I got it too hot.



Will try again Monday. Have poker tonight and fishing sunday night.

Just checking. My 1K ohm bag of resistors has brown, black, red bands. The way to hook it up is to remove the connector and insert the resistor in the two cavities of the connector. Leave the temp sensor out of the hook up. The resistor fakes a reading from the temp sensor so it appears to be warmed up to operating temp but not too hot.

 

[WadePatton]

ALLrighty then, put in a proper 1000 ohm resistor, same problem.



Fixed my DVOM as well.



Any more idears?

 

[Joe G.]

That's about all I can suggest without looking at it.

 

[Howard Durand]

Wade,



If your ohm meter is working, check the black wire on the ground side of the temperature sensor to see if it is really grounded.



The temperature sensor, when cold, applies a high resistance to the OD control circuit at the PCM. As the sensor temperature rises it's resistance drops and at some point, allows the transmission to shift into OD. lf the grounded side of the sensor is open, the transmission will not shift into OD no matter what resistor you put in.



Also, if the wire between the PCM and the sensor is open, that will have the same effect.



In that case, you could find the wire where it comes out of the PCM and attach the 1000 ohm resistor between it and ground.