Stylemobile

Found bits and pieces here on this issue but i am still not clear.

Kickdown issues. My trouble is it won't kick down fully. I get a one gear down 'kickdown' at WOT but i cannot get er to kick down to second like she used to when I stabbed the Go peddle. Issue came on suddenly. Fuse is OK. Also, my manual kickdown switch in parallel with the go peddle switch has no effect now when switched at any throttle load. Used to work great. Hmmnnn......
No 'clicks' at trans area when ignition on, in drive and pushing the KD switch behind the Gas peddle. KD Relay or KD solenoid at trans?
Indications on other posts seem to indicate it not related to the relay which is really a KD 'bypass' or sorts to upshift the trans at redline.

Your 2 cents?

Thanks,

Allen

Mongo

Can you confirm that the gas pedal is making contact with the kickdown switch fully? I had this issue too. It was solved with adjusting the pedal.

However, since you have the kickdown bypass mod, that would make adjustment irrelevant when it's activated. Try the relay. There are ways to test continuity with an ohmeter to verify connection.

WallyP

Quiet place, ignition on, flip the parallel kickdown switch - there should be a click from the solenoid on the transmission.

If there is no click, check for 12 vdc on the throttle switch - there should be power on one side. If so, press the switch (ignition on) - there should now be power on both switch terminals.

If you have power on both sides of the switch, move to the solenoid and check for 12 vdc on the solenoid wire with ignition on and throttle switch depressed. Repeat with the parallel switch.

If you have power at the solenoid, but no click, solenoid is faulty or sticking.

pcar928fan

I bet it is the solenoid! I used to burn mine out pretty regularly with all my track days! They have a limited life expectancy and it seems pretty low in my experience!

Stylemobile

Thanks for the step by step on how to diagnose, Wally. And thanks James for the personal experience synopsis. Good to know what can be typical or problematic. (As well as what is pretty reliable.)
I will post my investigation and remedy results here for all future searchers of this issue. These forums are a life saver (or at least a mechanical headache saver.)

Best,

Allen

Stylemobile

OK. Spent a bit more time on this. I checked voltage at either terminal socket 30 or 87 for relay #XV. I had voltage there (11.3V) with key on and in drive (engine not running). I next carefully opened the relay and applied 12VDC acros these terminals. The contacts did not move. Continuity between the terminals was open at rest and closed when I gently pushed the conyacys together. I tried jumpering terminals 30 and 87. There is no difference in the shift points when I drove her. The shift points remain as if there is still no kickdown response. I am not sure what unit is the solenoid on the transmission. I did check the single wire at the back with the push on (in) courrogated conector. I had no voltage there in any position.

Any more guidance?

WallyP

The kickdown solenoid is just above the left front corner of the transmission oil pan.

Quiet place, ignition on, flip the parallel kickdown switch - there should be a click from the solenoid on the transmission.

If there is no click, check for 12 vdc on the throttle switch - there should be power on one side. If so, press the switch (ignition on) - there should now be power on both switch terminals.

If you have power on both sides of the switch, move to the solenoid and check for 12 vdc on the solenoid wire with ignition on and throttle switch depressed. Repeat with the parallel switch.

If you have power at the solenoid, but no click, solenoid is faulty or sticking.

Stylemobile

Wally,
Thanks for informing me of the KD solenoid location.
So far I checked the throttle switch. It is functioning fine. Took her for a quick test drive. Trans kicks down from 4th to 3rd under throttle load but will not kick down to 2nd at any RPM or road speed. KD switch at throttle pedal and at parallel bypass still are inoperable. Have not checked solenoid voltage at trans yet (raining and have to do this outside for a while) but there was no click sound when checked before.
Question: If trans downshifts under throttle load from 4th to 3rd, could this still be a solenoid issue? I am confused about system operations and how they relate to each other.

Stylemobile

Although laying under the car with the *** end only 6 inches higher than normal and having eyes older than a youngsters may have something to do with it, I cannot locate the solenoid or it's electrical connection on the transmission. I cannot also find a decent image of it to document where it resides.
Anyone???

Mrmerlin

here is another link ,
https://rennlist.com/forums/928-foru...uto-928-a.html

Stylemobile

OK Here is a brief and uninteresting conclusion to my KD issue. I was cleaning contacts on the fuse panel and put the KD relay in the wrong position. Then I was trying to figure it out with the wrong relay chart for my model year. Duh.... I feel like qiute an idiot. (But I did learn alot and got great advice from patient and knowledgeable people. -and THAT"S why I love my 928!!!!)
For all future 928 people with a KD issue: Your KD will not work without the relay in it's proper place.

Thanks everyone!!!

Allen