Th400 electronic issue

[Blue Ox]

If I understand right I have the one on the exterior of my trans and the internal one. They are fired by the pcm what tells the pcm when to fire? TPS sensor haven't found I diagram yet.

In the dinosaur world pre "E" anything the kickdown switch was near the top of the gas pedal.

 

[Falkasorus]

It's now throwing codes 21 22 tps high and low voltage any specific place to start have a new sensor coming?

 

[Bextreme04]

It's now throwing codes 21 22 tps high and low voltage any specific place to start have a new sensor coming?

LOL, so it has both high and low voltage at the TPS??? Thanks OBD1

 

[Bextreme04]

Supposedly that can happen from large vacuum leaks, but I'm not sure how. Make sure the vacuum line from the manifold down to the modulator on the trans is hard line with just a short section of rubber and that the rubber isn't soft and weak or brittle/broken. That will cause large vacuum leak and problems with shift points at the same time.

 

[Falkasorus]

Checked that and replaced the modulator. Hopefully new TPS helps

 

[Matt69olds]

It's now throwing codes 21 22 tps high and low voltage any specific place to start have a new sensor coming?

The TPS is a simple 3 wire sensor. One wire will have 5 volts, one wire is ground, the other will be the signal wire to the PCM. Since it’s setting high and low voltage code, most likely either the wiring is screwed up, or the sensor is defective.

The kickdown solenoid connector is on the drivers side of the transmission car, just above the transmission oil pan rail. I’m pretty sure it’s a orange wire. Unplug it, it has zero effect of shift quality other than commanding the trans to downshift at WOT.

 

[rt66paul]

You could always wire it to a switch you control for kickdown. In the old days with manual transmissions, we actually used to downshift manually to get a passing gear. Manual valve body automatic transmissions did the same.

Imagine that! being able to drive a vehicle without sensors that vibrate your ass telling you there is a car to your right or left - you might have to drive the vehicle.

 

[Falkasorus]

I took it out the this weekend and drove it when it started acting up I pulled the guage/idle fuse and it went away plug it in and it was back immediately. Crawled under it and unplugged the selenoid and problem gone... now I have to figure out if my ecm is messed up and telling it to fire or if the selenoid wire isn't hooked up right. I vin searched my truck and it's a factory 305 that I would imagine paired with a th350 so wouldn't surprise me if when they put the new 350 in and paired it to a 400 they didn't do it right