HEY ALL! Great site. Looked at a lot of past posts, but have following problem on 1989 SE 120k miles:

Only code is 26, quad driver. SES on only when OD should kick in, light turns off when foot off gas pedal. Does not go into OD. Otherwise, does and always has run strong. ATF just flushed/changed as per info on this site. Old fluid was just slightly dirty; no chunks in pan. ATF Level good. Have also cleaned EGR.

Bought new computer off ebay, swapped, but same problem as before: no OD

How can I find out exactly what the problem with OD is? Can I clip OD wire, and force solenoid/transmission into OD with a toggle switch by hand (at the appropriate speed, of course), to test whether it is wiring or solenoid or if OD is just "broke"?

Really would like to get OD back...

Thanks
rm in raleigh

Thanks for the reply...

Pretty sure EGR ok, fans run, ac is off and not sure about canister.

SES will not light until engine comes up to temp, and speed is over about 45. Shifts normally up until then, but rpms don't drop to around 2k on the highway like it used to. I think we're on the same page.

Can solenoid be tested?
Can solenoid be changed with engine/trans in place?
Can canister be tested?

Can the TCC control wire be monitored with a volt meter if no scan tool is available?

I assume the OTC 2000 is the tool of choice to help with debugging...will I need the GM module for 1989 exactly? There seems to be a unit on ebay righ now but it goes to 1988...

thanks again,
rm

I just like the OTC 2000 (have two and are pretty cheap). Believe I have used an 88 GM cartridge (first year for "C" 3800) to check our 90 SE.

Can also just connect a DVM or even a test light to the TCC connector (is a 5v signal AFAIR). Should turn on when ECM commands. Keep in mind that the coolant temp must be over 146F and speed over 50ish mph with steady throttle.

I had an 84 Fiero for several years and the TCC never worked, even drove to Atlanta once that way. Just wound a bit higher.

Yea the lockup doesn't work in my car either, it never bothered me and i don't plan on removing the tranny again just to fix it. I wouldn't worry about it if i were you, it won't have any negative (mechanical) effects. Your mileage might be less though, but not much. maybe 1-3 MPG'*.

Ok...

I hear ya about lettin' it go, BUT, it not working now has driven me nuts for a while. Stupid light is just too bright at night, and since a 16yr old is scheduled to drive it, I really do not want any further distractions. Just don't think telling a kid to igore the light sets the right precedent...

I did have to repair a couple wires down around the cam sensor...apparently squirrels think wires taste good. Had to repair a bunch of wires on my Bronco for same reason, but that'* another story... Have traced tranny wires back to firewall, and looked pretty hard at other wires under hood but do not see any more damage.

SO....

When I looked at the Bonne schematic in the Haynes manual, the 5-pin connector on the tranny was not obviously called out...it appears kind of generic (unless I am blind...which I have been accused of before...) Does anyone know which wire in the 5-pin to look at for TCC?

And also, still trying to find out:
Can TCC lockup solenoid be tested?
Can TCC lockup solenoid be changed without pulling engine/tranny?

Thanks again,
rm

Look up in your Haynes troubleshooting for this condition.
I believe it said 2 conditions have to be met for lockup but don't remember which.
Temp.?

146*F, and 48mph [varies slightly by vehicle], in 3rd or OD, and with low throttle. I forgot the actual TPS voltage, but it'* the throttle you'd see on the highway or such. Light throttle.

According to my 1990 FSM, the torque converter solenoid is located inside the side cover of the transaxle, however, it is listed as a repairable item "on car". The solenoid receives straight 12 volt + through pin "A" on the connector (power comes from the brake switch), which is the lower left side when facing the connector on the trans. The ECM switches the ground on and off to activate the solenoid. The switchable ground is pin "D" , which is the lower right side facing the connector, in other words they are side by side. The wires color listed in the FSM are red (+) and black for ground. Essentially it should give an audible click if you apply power and ground to the connector. That doesn't guarantee it is completely functional, there can still be faults inside the transaxle but it is a start. Testing directly at the connector will bypass all of the conditions that must be met to cause lockup.