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1987 Jeep Cherokee : AISIN Warner : Question

1987 JEEP CHEROKEE CHIEF, 4Door,4WD, 6 cyl 4.0L Automatic VIN# xJCMRxxxxHTxxxxxx with a RENIX ECU and

Aisin Warner 30-40LE Transmission ============================================================

Any AISIN Warner Wizards out there?

What would be the reason the overdrive mechanism will not activate?

6 months ago I had a leak on the transmission line to the radiator. I temporarily lost all but 1st and 2nd gear while driving on interstate, repaired the leak, and refilled with proper fluid. No burn smells from the old fluid. I have all 4 gears and they upshift and downshift as if it is brand new ?-smooth, no noise, no vibration. Reverse sometimes has a slight engagement kick ( one in a blue moon ).

At 70 mph, I am in 4th @3100rpms and Overdrive isn?t taking over to bring rpms down to normal 2300rpms. Mechanical? Electrical? Internal? External?

Wizard advise is appreciated !!!

Thanks, Ken

Reply to
kjlouisiana
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Just a punt here, but it might be the computer needs resetting because you went into "limp home mode". So disconnect the battery for about half an hour then reconnect. Drive around the block a few times (no heavy use of the pedal) Then get out on the highway so it can go up through all the gears.

Reply to
DougW

Hi Ken, I only see your post via Doug's. You have an electronically controlled four-speed automatic transmission. Features selectable shift modes, power and comfort. The power shift provided better performance through higher-rpm up-shifts and faster downshifts, while the comfort mode was a much more relaxed shift, and also much more economical in its operation. If you are operating your transmission in the "Tow / Haul" mode, (switch on dash) the transmission will shift to 3rd gear and 4th only will be enabled under steady cruise conditions. God Bless America, Bill O|||||||O mailto: snipped-for-privacy@billhughes.com

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Reply to
L.W.(Bill) Hughes III

Reply to
L.W.(Bill) Hughes III

Thanks, Peter, Doug, Bill for responding.

I know I have a TCU under the passenger dash, a Renix under the driver dash, and a yellow adjustable AMC box (i think it has something to do with the cruise control -- but not too sure). Could my problem be in the Neutral safety switch (mounted on the passenger side of the transmission? I have changed out the ECU recently and the TPS having the battery disconnected for hours at a time, and grandma type driving after reconnecting it.

If it weren't for noticing the higher rpms, not feeling the OD planetary engaging in (a 5th gear of sorts), and having to milking out 16mpg with a light foot, there would no way be to realize a problem.

I do have a comfort switch only (I driven it through tanks of gas on both settings; no other transmission switch on the dash. "Tow/Haul switch"??? I do have a 4WD shifter, 2WD, 4H, N, 4L (all of it's functions are excellent)

Any of this stirs any additional ideas where a problem would likely be?

Thanks In Advance, Ken

L.W.(Bill) Hughes III wrote:

Reply to
kjlouisiana

Hi Ken,

Reply to
L.W.(Bill) Hughes III

Could be the brake light switch, remotely... At least some vehicles unlock the TCC, and drop out of OD when brakes are applied.

Reply to
PeterD

Hi Peter,

When you posted TCC, are you saying the transmission control unit (TCU) (also known as the TCM or TCC ? I understand your reply post as such....

Now you may be on to something!!! The BRAKE LIGHTING (as screwed up as it may sound) is wired through the transmission's neutral safety switch (NSS) on the side of the transmission. I have had suspicions about the contacts in it since the summer (aged case seal and contact point erosion).

The truth is I have had suspicions about EVERY PART OF THE DAMNED THING (smiles).

The more I think about it, I fiddled with the steering column around May to (1) tighten the swivel, and (2)replace the ignotion switch below, and YES, I remember adjusting the brake sensor at the peddle!!!! OUCH!

I think you've have given me the solution... I'll post when I get a result one way or the other.....

Thanks, Ken

(PS: Thanks Bill too)

PeterD wrote:

Reply to
kjlouisiana

Torque converter control AKA torque converter lockup... Found on some older automatics, and most newer ones. May not be applicable on your vehicle, I'm not sure.

Please do keep us updated!

Reply to
PeterD

Hi Peter,

When you posted TCC, are you saying the transmission control unit (TCU) (also known as the TCM or TCC ? I understand your reply post as such....

Now you may be on to something!!! The BRAKE LIGHTING (as screwed up as it may sound) is wired through the transmission's neutral safety switch (NSS) on the side of the transmission. I have had suspicions about the contacts in it since the summer (aged case seal and contact point erosion).

The truth is I have had suspicions about EVERY PART OF THE DAMNED THING (smiles).

The more I think about it, I fiddled with the steering column around May to (1) tighten the swivel, and (2)replace the ignotion switch below, and YES, I remember adjusting the brake sensor at the peddle!!!! OUCH!

I think you've have given me the solution... I'll post when I get a result one way or the other.....

Thanks, Ken

(PS: Thanks Bill too)

PeterD wrote:

Reply to
kjlouisiana

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