Lildj2983

ok. i still have my 1999 honda prelude base model auto.
i put the auto trans back in. got ride of the p0740 i think it was. now having a p0715. DO NOT SAY TRANS IS FAILING NOT EVERY CODE MEANS ITS FAILING. so dont say that please.
ok i had to adjust the tps. from 11.7 at idle down to 8.4 at idle. trans shifts great but when i hit passing gear it feel like im hitting the brakes. and my speedomoter,temp gauge,fans all work and looking at freezeframe data when it throws a code nothing looks out of place. and i cleaned and tested the soleniods and that cleared the other code it was throwing. so any REAL ideas of what to take a look at?

backinblue92

iTrader: (1)

Your trans is failing.


Lol jk. I had to look it up but that code is your input shaft speed sensor. Which ur having speed-related issues with the tranny.

Lildj2983

well i believe the speed sensor is fine. it works and i unplugged the speed sensor closest to the passer frame rail to check and see what happened. it threw a completely different code. still trying out different things now. trying to see what the voltages and ohms should be on everything now.

minilogoguy18

It's not going to drive right until you fix that DTC, that sensor is there to monitor gear slip. The PCM is programmed to know the gear ratios of the transmission so if it sees that input shaft speed is too fast or slow compared to output shaft speed in any gear the car will not shift correctly. The VSS is pretty much your output shaft speed sensor that the PCM monitors as well to detect gear slip.

The values you're giving for what I'm assuming is throttle position are odd. The circuit is only a 5V circuit using 0V and 5V for diagnostic purposes while everything else in between is used to calculate throttle position which should be 0.45V closed and 4.5V WOT.

Lildj2983

guess i should have specified. i used my code scanner to get those numbers so i believe its not actual voltage more like a percentage and i already know it wont drive right until i fix that dtc. i just bought a volt multi meter so when the rain stops i will be able to start writing down my sensor info.

minilogoguy18

Well the throttle should not be open at all at idle, only newer cars do this by using the electronic throttle body to idle the car rather than an idle air control valve. If the throttle is open at all at idle you need to address that problem as well, the air bypass screw lets the car idle while the IACV just keeps it steady.

That DTC btw can mean there is a mechanical problem, metal particles in the transmission can affect the sensor reading. Use this and just in case you are new to electrical diag, NEVER, EVER measure resistance/continuity of wires with components or control units connected and NEVER measure a control unit directly. To measure resistance a DMM sends a small amount of amperage and voltage and this can damage solid state control units. Yes, I have seen rookies do this many times when working at the dealer.

https://www.dropbox.com/s/mkx9t5kqax...4074A.pdf?dl=0

Lildj2983

you have one of those that are readable? i cant read that honestly. im not new to electrical testing. i scored perfect in the electrical class at UTI back in 2008. im really good with wiring diagrams and understanding it all. and yes i agree. i also have seen many ASE master mechanics screw up making rookie moves. ASE certification dont mean anything if you dont have the knowledge lol. since the rain has stopped i will be going out there and pull some tests on the tps and speed sensor and check the wiring real good. looking at a diagram i know which wires to check at the PCM.

minilogoguy18

I just uploaded it to my dropbox as a downloadable pdf, it got messed up when trying to upload it as an image.

Lildj2983

ok the tps did test out fine. will test more when the rain stops again. can you email it to me?

minilogoguy18

The link is in the post above, it works, I edited the post.

Lildj2983

ok. well i got it figured out. it shifts ok. not the best but when i hit passing gear at 60mph in the rain it spun the tires to 70 then caught traction. ok for clarification the main shaft speed sensor is not mixed in with the VSS like everyone says it is. on the prelude its mounted under the battery tray. i had to remove the battery tray. looked at a schematic of the trans itself and found it. im assuming when i put in the battery trade i must have knocked off the plug because it backed off just a little bit.so now its not throwing a single transmission code. thanks for everyones help. now just have to do some body and paint work then put a new EGR valve then i will be selling my prelude.