i bought an '88 b2 with an earlier a4ld (2 wire). trans had serious previous owner problems (BROKEN FLEX PLATE AND CRUNCHED TORQUE CONVERTER PILOT DUE TO INCORRECT INSTALL. MAJOR PROBLEM WAS SEVERE SLIPPAGE IN 3RD. TCC WIRE WAS HANGING LOOSE, BUT 3-4 WIRE WAS ON ITS PIN. SWAPPED TO AN '89 TRANS AND ALL WORKS WELL EXCEPT THE COMPUTER WILL NOT (sorry about the caps) activate the solenoids. i tied in 3 test leads on the control wires and if i switch the tcc and 3-4 wires to ground, they work ok. if i do the output state test with a voltmeter tied between tcc or 3-4 wire and 12v lead, there is a 1 1/2 - 2 volt drop as i activate the test with the throttle. i am guessing this means in test mode, the solenoids are being activated, but i don't get the 0-12v i thought i would get. when i watch the meter in place while driving, i can't tell if anything is changing, but the computer does not activate the shifts. the engine sensors all seem ok and the vss ohms ok, but i didn't check it to the computer. only codes are 89 and 86. i did check continuity from the eec connector to my test leads.
anything i am missing? how do i get the 0-12v change on the output test?

 

Sometimes it is hard for me to picture exactly what other people are doing based solely on a brief written post on the internet. If I've understood correctly, it looks to me like there is something still wrong with the TCC and 3-4 shift solenoid circuits -- the PCM would not set a KOEO or CM 89/86 unless there was a pretty obvious fault in those circuits.

If I can suggest a very specific test (which you might have already done, it is hard for me to tell), we should be able to narrow this down.

0) Check and be absolutely certain the solenoids are getting power (red wire) at the transmission.
1) Hook up your voltmeter so you are measuring the voltage drop across the PCM -- pos lead going to the wire/pin for either the TCC solenoid or the 3-4 shift solenoid and neg lead going to ground. This arrangement should allow you to see what the "switch" inside the PCM is doing.
2) Enter output state test. As you cycle the throttle, you should see the voltmeter switching from 0 V (switch closed) to 12 V (switch open).
3) If you are seeing a "high" voltage (10-12 V) all the time, that suggests that something has failed inside the PCM (or in the connector or in the grounds)
4) If you are seeing a "low" voltage all the time, that suggests some fault up stream of the PCM - perhaps a bad connection between the trans and the PCM, or a bad connection in the power wire to the trans, or the solenoids have failed together.

 

0) there is 12v at the red wire
1, 2,3,4) with a cold engine, there is 11.95 v to 11.85v in output test activated/unactivated
so i guess its the pcm.

does a warm engine make a difference?
seems the last time i did it it was warmed up.

 

Not the times I've done it.

 

i pulled the computer apart and found a burnt circuit on the board. wired in a jumper and it still doesn't go into od. hard to tell if it does tcc, and now the voltage stays low while driving. more than likely whatever took out the circuit took out something else.
thanks for the help

 

According to those who dig inside these computers, that's usually what they describe -- something burnt out a specific component (or a few components) which takes out certain circuits.

 

fwiw, i got a rebuilt eec and all is now well.

thanks again