TCC Solenoid again

[Sunshine]

I hope you help me out here, the new solenoid # 24210864 TCC PWM that i ordered measures 10.3 Ohms more or lest the same as the old one, understanding from a Component Resistance Chart i have it should be between 20-40 Ohms. Have got a bad egg..?

Thanks for any help.

/Paul

 

[gmctd]

Hi Paul -

#1 - Where did you get the resistance values for that solenoid

#2 - What were your original symptoms?

 

[Sunshine]

Hi Paul -

#1 - Where did you get the resistance values for that solenoid

#2 - What were your original symptoms?

Hi gmctd

#1- The 4L80-E Component Resistance Chart was sent to me from DTR member
docdray


#2- It is in my process to try and eliminate the hassle i have with the ABS, in
which i have read that this could be the problem with some of the
solenoids in the tranny.

As they are a few months away from being 14yrs old while the pan is down i decided to re-place all..

 

[gmctd]

There are two TCC solenoids, one 20-40ohm for the 4L60E, strictly on or off, and one 10-15ohm for the 4L80E, which is PWM - their impedance values are not similar, and they are not physically interchangeable - iirc, the value was changed between OBD1 and OBD2 - if your oem solenoid is 10ohms, the replacement should match that - if they have the commutating diode installed, switch the meter leads to reverse-bias the diode and get the actual coil dc resistance

Any DTC's? Have you disconnected and reseated the various wheel-speed sensor connectors, incl the main ABS module connector?

 

[Sunshine]

There are two TCC solenoids, one 20-40ohm for the 4L60E, strictly on or off, and one 10-15ohm for the 4L80E, which is PWM - their impedance values are not similar, and they are not physically interchangeable - iirc, the value was changed between OBD1 and OBD2 - if your oem solenoid is 10ohms, the replacement should match that - if they have the commutating diode installed, switch the meter leads to reverse-bias the diode and get the actual coil dc resistance

Any DTC's? Have you disconnected and reseated the various wheel-speed sensor connectors, incl the main ABS module connector?

jd, I`m on my way,,the milkyway, boy you impress me. you`l have to slow down a bit, y`ll giving me brain (1 cell) damage.

 

[Sunshine]

There are two TCC solenoids, one 20-40ohm for the 4L60E, strictly on or off, and one 10-15ohm for the 4L80E, which is PWM - their impedance values are not similar, and they are not physically interchangeable - iirc, the value was changed between OBD1 and OBD2 - if your oem solenoid is 10ohms, the replacement should match that - if they have the commutating diode installed, switch the meter leads to reverse-bias the diode and get the actual coil dc resistance

Any DTC's? Have you disconnected and reseated the various wheel-speed sensor connectors, incl the main ABS module connector?

Mike L. ,,,,hello,,MIKE do i have to shout can you chime in here, it`s Christmas, if it`s food ,, let me know... sometimes your worse than my Viking Wife,,,Mike forget about the Party Zone

 

[docdray]

my 94 4l80e shop manual lists tcc as 20-40ohms(as mine tests), since his vehicle is 95 and obd-II started in 96, is there a solenoid design upgrade or change? possibly a technial note i have missed on OBD-I as I really don't delve into OBD-II until 2006 models and do not have full info on trannys for them?

the original problem sounded like vss sensors affecting ABS, or a bad ABS bpmv. have you ben able to check those issues, sunshine?

 

[Sunshine]

my 94 4l80e shop manual lists tcc as 20-40ohms(as mine tests), since his vehicle is 95 and obd-II started in 96, is there a solenoid design upgrade or change? possibly a technial note i have missed on OBD-I as I really don't delve into OBD-II until 2006 models and do not have full info on trannys for them?

the original problem sounded like vss sensors affecting ABS, or a bad ABS bpmv. have you ben able to check those issues, sunshine?

Put in a new vss, to put in a new brake switch & to check the bpmv is next on the list.

I would not have thought there was a change between 94-95..?

 

[docdray]

if vss's are bad, that could throw codes indicating bad bpmv. might save money by clearing codes and then see if the bpmv is bad.

 

[gmctd]

The FSM's are fraught with unpardonable errors - certainly not the least of which concerns the 4L80E TCC solenoid dc resistance value: indicated value is 20-40ohms - real-life works-fine-lasts-a-long-time value = 10-15ohms - read and heed - also, now would be prime time to correct your books'n'charts, kiddies

Now, since you've rattled my cage, and as long as I'm on this kick, a word or several vis a vis the differences in lockup function between the 4L60E and the 4L80E:

4L60E TCC is direct lockup, where +12v is placed on the TCC solenoid to apply the TC clutch for hard lockup - the TCC solenoid is higher impedance at 20-40ohms so as not to overheat and self-destruct with constant applied power - not much torque is being applied thru the hollow input shaft, so this method is entirely functional in the wimpy 4L60E

4L80E TCC is soft-apply by modulation of the TCC solenoid according to torque requirement, which means the TCC is never fully applied - the TCC solenoid is lower dc resistance to achieve quicker response with the effectively lower voltages applied via the Pulse Width Modulation scheme - PCM applies a fixed frequency, varying the width of the pulses according to torque requirements - narrow pulses = low averaged voltage, TCC is lighty applied - wide pulses = higher averaged voltage, TCC is more firmly applied - there is no hard lockup due to large amounts of torque that can be applied to the hollow input shaft - the 4L80E hollow input shafts have a history of breakage in 3500-series wrecker and dump-truck service, thus the soft-apply scheme - the direct dc solenoids are 20-40ohms - the modulated solenoids are ~10-15ohms.

So, after that long slow curve, now for the quick pitch - read and heed, kiddies: there are several hard-lockup schemes available, whereby a simple switch applies direct battery power to the low-resistance PWM solenoid - not good, as the resistance is too low for sustained constant +12v service, overheating the solenoid coil, and hard-apply increases probability of input shaft failure - while there has been some success in using the schemes, you should still be aware of the imminent danger and probability of failure

Basically, by improving the venerable T400 HD 3sp turbohydramatic trans with overdrive and a lockup convertor, engineering created a fatal error by boring several holes (hydraulic fluid passages) in the input shaft in that bad boy - hard evidence of that error is: soft-applied TCC unlocks anytime the driver eases up on the go pedal, any speed, any load

That's my story, and I'm stickin' to it.......................