OVer Drive Problem and Codes

[Sentry6]

Have several problems perhaps all related:

NO OD, NO Converter Lockup, No Speedometer (cable driven?), no cruise

Codes:
629 - TCC solenoid circuit failure
566 - 3-4 shift solenoid circuit failure
452- no input from speed sensor

im guessing i have a bad speed sensor, but can a bad sensor cause the other codes, or could they be an idependant problem, also speedometer was working befor and i didnt have OD or tcc lockup

Thanks

 

[MrShorty]

A bad speed sensor can cause it not to shift into 4th gear or not to engage the torque converter lockup clutch (TCC), but it will not cause those codes. Really, there are only two things that cause the solenoid circuit fault codes: 1) the circuit is open or 2) the circuit has a short to ground.
I'm going to ask, in part because I ask everybody. Are those KOEO codes or continuous memory (CM) codes? If you don't know how to distinguish them, read through your instructions (a good set is at www.dalidesign.com/hbook/eectest.html) for the KOEO test. KOEO codes indicate a hard fault that is always (or nearly always) present. A CM code without and accompanying KOEO code indicates a more intermittent fault, and you need to adjust your diagnosis strategy accordingly.
For diagnosing the solenoid codes, you need to get a wiring diagram and go through each circuit until you find what is shorted or open or which connector isn't plugged in. Because you have both transmission solenoid codes, I'd start with what they have in common: the power supply from the EEC relay.
For the VSS code, check the wiring between the VSS and the PCM first, then check the sensor. If it's a KOEO code, then the fault almost has to be electrical. If a CM code, then it's also possible that one of the gears to the speed sensor is stripped and the VSS is therefore not getting any data.

 

[Sentry6]

Thanks for the info and quick reply, the first 2 (solenoid codes) are koeo, and VSS is a CM code.

Update: ***

i went to remove the old vss, and it fell apart lol.. 2 half's... anyways removed it and installed the new vss, also checked connector at transmission seems slightly loose.. will drive it later and see what happens

thanks again for the info

 

[Sentry6]

Ok, i checked power all the way to the transmission, and no problem found, also checked harness for rubbing and didnt find any broken wires, is it possible that both solenoids have failed? one thing i havent checked is the connector contacts at the transmission (little hard to get to).. maybe drop the pan and check continuity on the inside of the transmission?

Thanks!!!

by the way, speedo, and cruise work fine now...

 

[MrShorty]

That works. It depends on if you think it's easier to drop the pan to check the continuity of the solenoids or easier to find someplace else to tap into the wires. If it were me, I'd probably go to the wires between the solenoids and the PCM and see if I had 12 V there. If you have 12 V before the solenoids (the red wire going into the transmission) and 12 V after the solenoids, that suggests that there is continuity through the solenoids. After that, it would be easier to check (in my opinion) the solenoids by testing the voltage drop across the solenoid while open and closed. This is easily done using the output state EEC-IV test. Output state test comes up just after the KOEO test: see instructions.

 

[Sentry6]

make sure im doing this right, checked for continuity between red wire (+side) and switching side forgot colors purple w/yellow etc. (- side) both solenoids have "0" continuity.. or am i testing wrong?

 

[Sentry6]

sorry to keep adding to the post, but i have more info...

hooked up a multi meter to the purple/y orange/y (1 at a time) and drove the xp.. noticed that at the purple/orange wires i always have 12neg. is this normal? IE does the selenoid always have 12volts to it, and the computer switches it off to release selonoid to activate OD or TCC?

 

[MrShorty]

If I understand your last question and you've hooked it up backwards (negative lead to the p/y or o/y. positive lead to ground), then that sounds normal. The solenoids are ground side switched, which means they are always connected to B+ when the key is on (review your wiring diagram to see that this is true).
Not sure where you are connecting your continuity tester for the continuity test, but there should be a measurable resistance (don't have the exact value in front of me) through each solenoid.

 

[Sentry]

Ok, first item , what i ment was that i hooked negative lead to p/y or o/y yes and red lead to battery + and i always have 12volts with the key on or off..

second item, yes i was measuring continuity accross the solenoid, and i have non at all, on either one..

 

[Sentry6]

I guess all i need to know is whats the normal output state from the computer when there is no call for tcc or OD, is it grounded signal, and when it calls for od/tcc it turns the ground signal off and allowes the solenoid to spring open?

 

[MrShorty]

To answer your second post, you have the basic idea, just backwards. When the "switch" inside the computer is open (ie "off" ie no current flowing through the circuit), the transmission is in 3rd gear/TCC disengaged. When the computer decides to shift into 4th/engage TCC, it closes the "switch" (ie turns "on") and allows current to flow through the solenoids, which causes the transmission to shift (assuming the hydraulic and mechanical mechanisms are all functioning properly). This could be exactly what you described, and I just misinterpreted your last post. If so, then my apologies for misunderstanding; I just want to make sure we're understanding.
As for the previous post, your voltage test key off is normal. KOEO, I would expect that voltage test to show a very low voltage (almost 0) since both of those points are on the + side of the computer "switch," and no current is flowing.
Depending on exactly where you measured the continuity, it appears to me that you've isolated the circuit fault to be between those points. If there was any wiring external to the transmission in that continuity test, make sure it's good before opening the transmission. If the continuity test was performed at the case connector, then it sounds like it might be time to drop the pan, check the wiring between the case connector and the solenoids, and check the solenoids themselves.
Considering the timing of your posts, you might already be ahead of me, but in any case, good luck, and let us know how it goes.

 

[Sentry]

hi thanks again for the quick reply, hate to be a pain, but i think im a bit confused lol... with the key on and engine off, if i put negative lead on orange yellow, and red lead on red wire, i have 12v, not till i turn the key off do i lose the 12v.

now i know the red wire will always be hot with the key turned on because that is feed by the eec relay. what im wondering is, is it normal for the p/y o/y wires to always be grounded?

 

[MrShorty]

No, that would not be normal. Those wires are grounded through the "switch" in the PCM, and then only when the computer decides to shift into 4th/engage TCC.

 

[Sentry]

ok great thanks, now im starting to get to the problem

ok,if there grounded wouldnt OD/TCC be always engaged?

so first step in diag would prob be disconnect pcm and see if i lose continuity to ground..

Thanks again, have been a great help