Krambo Posted January 18, 2005 Report Share Posted January 18, 2005 A while back my truck had a major issue with the tranny and threw a code. The issue was that the truck seemed to be stuck in 3rd gear. It would shift each gear if done manually however, when put in "D", it felt like it was in 3rd gear. The trans temp went a hair over 200* (atypical for my set-up). The situation corrected itself and things were normal after about 2 miles. The same situation happened 2x after that and has not happened for 8 months. I had the codes scanned for inspection and code p0742 (I think, trying to remember off the top of my head) came up. It stated that solenoid B was stuck in the open position. I am not much of a tranny guy so can someone explain the issues I had and possible causes? Was the tranny damaged? Link to comment Share on other sites More sharing options...
zippy Posted January 18, 2005 Report Share Posted January 18, 2005 some info... Circuit Description The torque converter clutch (TCC) solenoid valve is a normally-open exhaust valve that is used with the torque converter clutch pulse width modulation (TCC PWM) solenoid valve in order to control fluid acting on the converter clutch apply valve. The TCC solenoid valve attaches to the transmission case assembly extending into the pump cover. When grounded, energized, by the powertrain control module (PCM), the TCC solenoid valve stops converter signal oil from exhausting. This causes converter signal oil pressure to increase and move the converter clutch apply valve against spring force and into the apply position. In this position, release fluid is open to an exhaust port and converter feed fluid fills the apply fluid circuit. The converter feed fluid applies the TCC. When the PCM no longer provides a ground path, the TCC solenoid valve de-energizes and apply fluid exhausts, releasing the TCC. When the PCM detects low TCC slip speed when the TCC is commanded OFF, then DTC P0742 sets. DTC P0742 is a type B DTC. Conditions for Running the DTC No TP sensor DTCs P0122 or P0123. No VSS assembly DTCs P0502 or P0503. No TCC solenoid valve DTC P0740. No TFP manual valve position switch DTC P1810. No TCC PWM solenoid valve DTC P1860. The TP angle is 17-45 percent. The engine speed is greater than 450 RPM for 6 seconds. The engine is not in fuel cutoff. The TFT is between 20-130°C (68-266°F). The engine vacuum is 0-105 kPa (0-15 psi). The engine torque is 67-542 N·m (50-400 lb ft). The engine speed is 1,000-3,000 RPM. The speed ratio is 0.64 to 1.35. The vehicle speed is 24-80 km/h (15-50 mph). The gear range does not change within 5 seconds. The commanded gear is not 1st. The gear range is D4. The TCC is commanded OFF. Conditions for Setting the DTC DTC P0742 sets if the following condition occurs twice. The TCC slip speed is -20 to +20 RPM for 5 seconds. Action Taken When the DTC Sets The PCM illuminates the malfunction indicator lamp (MIL) during the second consecutive trip in which the Conditions for Setting the DTC are met. The PCM inhibits the TCC. The PCM inhibits 4th gear in Hot Mode. The PCM freezes shift adapts from being updated. The PCM records the operating conditions when the Conditions for Setting the DTC are met. The PCM stores this information as Freeze Frame and Failure Records. The PCM stores DTC P0742 in PCM history during the second consecutive trip in which the Conditions for Setting the DTC are met. sounds like you may have a wiring problem or a failing tcc solenoid. this can also be caused by a bad tc. Link to comment Share on other sites More sharing options...
Dylan06SS Posted January 19, 2005 Report Share Posted January 19, 2005 zippy... is there any trans question you can't answer? Link to comment Share on other sites More sharing options...
Krambo Posted January 19, 2005 Author Report Share Posted January 19, 2005 whewww! That was alot of info to digest in one sitting! Thank you for the information! Now, to investigate.... Thanks again Zippy! Link to comment Share on other sites More sharing options...
shadowsniper3006 Posted September 3, 2008 Report Share Posted September 3, 2008 sorry to bring up an old post guys but i'm trying to see what i have going on with my trans. After i put in a 3800 stall converter when i'm driving around town i got the p0502 and p0742 codes at different times. I also got the p0502 code when i brake stalled to 3800 for a longer time then usauly do. Krambo what did you find out about your trans? Where is the TCC solinoid on the trans? Is this something going bad or caused by the high amount of stall and the sensors are confused(much like me right now) and just needs to be tuned? Thanks guys! Brad Link to comment Share on other sites More sharing options...
04CHASE Posted September 3, 2008 Report Share Posted September 3, 2008 i know with a loose converter , i think its p0757 code thats for solenoid b and i and others have had it thrown when going with something looser than around 3k. but not always. i have an aeroforce so i can always clear it and it would be ok , it would only occur when there was a slight load ont he engine and not giving it slowly increase throttle. where it would want to downshift yet throw the code , usually going up hills. Link to comment Share on other sites More sharing options...
shadowsniper3006 Posted September 3, 2008 Report Share Posted September 3, 2008 wow thats right when it threw the code, i was stopped on hill and started to roll backwards and i gave her a little gas to get to the stop sign again. I have the scan gauge to reset it and went right back to normal. So this is not a mechanical problem that needs to be fixed? Just something i might have to live with, or can it be tuned out? Thanks Chase! Brad Link to comment Share on other sites More sharing options...
misterp Posted September 3, 2008 Report Share Posted September 3, 2008 i know with a loose converter , i think its p0757 code ... it would only occur when there was a slight load ont he engine and not giving it slowly increase throttle. where it would want to downshift yet throw the code , usually going up hills. My converter does the exact same thing, if I the truck kicks down from 3rd to 2nd under *very* light throtttle it'll trip this code. Imagine, stuck following a little old lady going up a 3-5% grade at almost no throttle, the truck will ever so gently downshift and the MIL comes on. Mr. P. Link to comment Share on other sites More sharing options...
Krambo Posted September 3, 2008 Author Report Share Posted September 3, 2008 I was able to get rid of this issue (at least it hasn't happened since,...3+ years) by doing three things in my tune: 1. Narrowed my TCC lock up / release MPH points in my tune. I had them farther apart (about a 10MPH+ spread) than most people, which I liked due to not having the converter lock and unlock when cruising around in my "hilly" area however this was suggested to me by a local LS1 tuner. I now have about a 5 - 8MPH spread under 50% TPS. 2. I also Zero'd my shift times since I had a shift kit. 3. I set my TCC duty cycle MAX table to 100 and the TCC duty cycle MIN to 90. Maybe Zippy can comment on what I did and if that was appropriate for this situation. Since I haven't had this issue since, I figured it worked. However could be wrong... Link to comment Share on other sites More sharing options...
shadowsniper3006 Posted September 3, 2008 Report Share Posted September 3, 2008 Thanks for the reply Krambo. Hopefully at the end of the month Zippy will be tuning my truck again so if he doesn't check in here i'll print this off for him. Thanks guys Brad Link to comment Share on other sites More sharing options...
misterp Posted September 3, 2008 Report Share Posted September 3, 2008 Thanks Krambo, I'll experiment with those params. - Mr. P. Link to comment Share on other sites More sharing options...
zippy Posted September 4, 2008 Report Share Posted September 4, 2008 Thanks for the reply Krambo. Hopefully at the end of the month Zippy will be tuning my truck again so if he doesn't check in here i'll print this off for him. Thanks guys Brad We should be able to fix this. I was wondering if you'd run into this problem or not. Call me if you get some time and we'll get a jump on it. You still have an extra pcm right? Link to comment Share on other sites More sharing options...
shadowsniper3006 Posted September 4, 2008 Report Share Posted September 4, 2008 We should be able to fix this. I was wondering if you'd run into this problem or not. Call me if you get some time and we'll get a jump on it. You still have an extra pcm right? I have 2 extra PCM's. Right now one programed for the larger tires and 2 for the 245-45's. I'll see if i can give you a call tonight, are there any times i should not call, like what time you eat dinner, after 8pm or 9pm or ??? Tonight it would have to be after 6:30ish. If you check my sig. out you'll see the other stuff i hope to have done before you come to town to. Thanks Zippy! Brad Link to comment Share on other sites More sharing options...
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